Device, method, and graphical user interface for extending functionality of a host application to another application

A host application executing on a client device includes a content processing extension that extends its functionality to process content items to a requesting host application executing on a client device. The content processing extension is an executable file that includes data conversion code and application code. The data conversion code, when executed in requesting host application, identifies content items provided by the requesting host application and formats the identified content items to be received by the content processing extension. The application code is native code executable by the host application associated with the content processing extension. The application code processes the results from execution of the data conversion and the identified content items in accordance with one or more functions of the host application, and returns the processed content items to the requesting host application via the content processing extension.

TECHNICAL FIELD

This relates generally to a host application executable by a computing device. More particularly, the disclosed embodiments relate to providing an extension of a host application extending functionality of the host application to another host application executable by the computing device.

BACKGROUND

Security concerns for all types of processor-based electronic devices, and particularly for computing devices, have become a significant concern. While some concerns may relate to detrimental actions which may be undertaken by defective code implemented by such devices, the greater concerns relate to the ramifications of various types of attacks made upon such devices through malicious code, including code conventionally known in the field by a number of names, including “viruses,” “worms,” “Trojan horses,” “spyware,” “adware,” and others. Such malicious code can have effects ranging from relatively benign, such as displaying messages on a screen, or taking control of limited functions of a device; to highly destructive, such as taking complete control of a device, running processes, transmitting and/or deleting files, etc. Virtually any type of imaginable action on a processor-based device has been the subject of attacks by malicious code.

Many of these attacks are directed at computing devices, such as workstations, servers, desktop computers, notebook and handheld computers, and other similar devices. Many of these computing devices can run one or more application programs which a user may operate to perform a set of desired functions. However, such attacks are not limited to such computing devices. A broader group of various types of devices, such as cell phones; personal digital assistants (“FDA's”); music and video players; network routers, switches or bridges; and other devices utilizing a microprocessor, microcontroller, or a digital signal processor, to execute coded instructions have been the subjects of attacks by malicious code.

In one particular situation, one application such as a browser application may have to invoke a plugin (also referred to as an application extension), which may be developed by a third party. Typically, when an application invokes a plugin that is associated with the application (also referred to as a host application), the operating system launches the plugin within the same process address space of the application, as shown inFIG. 1. Referring toFIG. 1, when application104invokes plugin105, application launch module102of an application manager101loads plugin105within the same process address space106of application104. Since application104and its plugin105are running within the same address space106, plugin105may be able to access resources that are accessible by application104, where the resources may be managed by resource manager103. From the view point of resource manager103, application104and plugin105are the same process. That may cause application104to be vulnerable if plugin105turns out to be malware.

For example, if plugin105is a third party plugin developed for application104and if application104can access a local storage and a network, plugin105may exploit and attack the files stored in the local storage and the network. In addition, even if plugin105is not malware, when plugin105crashes, it may bring down application104or cause application104to malfunction. Furthermore, when plugin105is terminated by launch module102, the termination of plugin105may cause application104unstable since they are in the same process address space106.

A conventional system utilizes a customized universal resource locator (URL) scheme for inter-process communications between two applications, which suffers from discoverability limitations, security concerns, and a general lack of flexibility where bi-directional communication is difficult and fragile. The URL schemes may cause an application to switch to the host application, which may bump the user out of the initiating application and destroy any of the visual context and the associated workflow will be lost. It is very difficult to detect such a situation.

A number of methodologies have been used in an attempt to reduce or eliminate both the attacks and influence of malicious or defective code. Generally, these methodologies include detection, prevention, and mitigation. Specifically, these methodologies range from attempts to scan, identify, isolate, and possibly delete malicious code before it is introduced to the system or before it does harm (such as is the objective of anti-virus software, and the like), to restricting or containing the actions which may be taken by processes affected by malicious or defective code. However, there has been a lack of efficient ways for handling a plugin associated with an application that invokes another application in a secured manner.

SUMMARY

According to some embodiments, a host application includes a content processing extension that extends its functionality to process content items to a requesting host application executing on a client device. The content processing extension is an executable file that includes data conversion code and application code. The data conversion code, when executed in requesting host application, identifies content items provided by the requesting host application and formats the identified content items to be received by the content processing extension. In some embodiments, the data conversion code comprises a set of instruction written in a scripting language such as JavaScript™, or any other programming language that is executable by the requesting host application. The application code is native code executable by the host application associated with the content processing extension. As used herein, native code refers to code that is executable by a specific application or without additional components. The application code processes the results from execution of the data conversion and processes the identified content items in accordance with one or more functions of the host application and returns the processed content items to the requesting host application via the content processing extension. The application code also launches the content processing extension in a separate sandboxed environment and facilitates an inter-process communications (IPC) mechanism or framework between the requesting host application and the content processing extension. The IPC communication mechanism allow the requesting application to access the functionalities of the content processing extension via the IPC communications mechanism, while preventing unauthorized access by the requesting host application of sensitive information about a user accessible by the host application.

DETAILED DESCRIPTION

Application Extension Framework

The extension framework includes a set of extension interfaces, referred to herein as extension points, to allow a first application (e.g., a requesting host application) to invoke an extension of a second application to access a set of predefined functionalities associated with the second application, which is extended by the extension (referred to herein as an extended service or extension service). The set of extension points may include various commonly used or popular functionalities or services associated with the operating system. An extension point defines a set of predefined application programming interfaces (APIs) or communications protocols that allow a client, either being the first application or the second application, to access or provide a service from and to another client. A service provided by an extension point may be provided by a standard component of the operating system or a third party function provided by a third party vendor.

In one embodiment, the extension framework operates as a connecting operator between two processes (e.g., an extension and a host application). The extension framework provides the discovery aspect and extends the security domain. When a first application is configured to access a predefined functionality (e.g., photo editing or photo filtering) provided by another application, the first application communicates with the corresponding extension point associated with that predefined functionality to inquire about who can provide such a service. The extension framework in turn searches and identifies a list of one or more extensions provided by other applications that have been registered with the extension framework to provide the requested service. The extension framework may return the list of the identified extensions to allow the first application, such as a content viewing application or web browser, to select one of the second applications, such as a messaging or social networking application, in the list for the requested service. In response to a selection of one of the extensions, which may be provided by or associated with a second application, the extension framework launches the selected extension in a separate sandboxed environment and facilitates an inter-process communications (IPC) mechanism or framework between the first application and the selected extension to allow the first application to access the functionalities of the selected extension via the IPC communications mechanism.

According to one embodiment, an extension point acts as an interface for a software developer for an extension and provides a domain that the extension operates. Each extension point is associated with a predefined set of policies (e.g., resource entitlements or restrictions) and specifies what messages can be exchanged between the host application and the extension. All extensions designed for a particular extension point must comply with the specification set forth in the predefined policies of that particular extension point. All extensions, when executed in an operating environment, are entitled to or restricted by the same set of operating environment parameters defined by the associated extension point. When the extension of the second application is developed, a developer can utilize an extension template associated that particular extension point as part of a software development kit (SDK) to generate executable images of both the second application, referred to herein as a container application, and the associated extension. The extension and the container application may be released in a bundle. The bundle includes the container application and its metadata describing the container application, and the extension and its metadata describing the extension. However, the container application and the extension can be launched in separate sandboxed environments and operated independently, which may be configured based on their respective metadata and/or the corresponding extension point, although they may access or share a common library or framework.

FIG. 2is a diagram illustrating a system architecture for managing application extensions in accordance with some embodiments. Referring toFIG. 2, system200represents any kind of data processing system including a processor, such as, for example, a server, a desktop, a laptop, a tablet, or a mobile phone, etc. System200includes an application manager201having an application launch module202and a resource manager203for launching and managing applications, such as application204and application extension205, executed within system200by processing resources (not shown). Processing resources may present one or more processors or processor cores. A physical processor typically refers to an integrated circuit, which potentially includes any number of other processing elements, such as cores, accelerators, or hardware threads. A core often refers to logic located on an integrated circuit capable of maintaining an independent architectural state, where each independently maintained architectural state is associated with at least some dedicated execution resources. A processor configured to execute instructions to extend the functionality of container application to another host application executing on a client device is disclosed herein.

Application manager201may be a part of an operating system (OS) running and executed by the processing resources within system200. An operating system is a collection of software that manages computer hardware resources and provides common services for computer programs. Application programs usually require an operating system to function. Amongst many functionalities of an operating system, scheduling is the method by which threads, processes or data flows are given access to system resources (e.g. processor time, communications bandwidth). This is usually done to load balance and share system resources effectively or achieve a target quality of service. In addition to application manager201, an operating system may further include other core components, such as a scheduler, a device manager, a kernel, etc. In order not to unnecessarily obscure the embodiments, these components are not shown herein. Note that application launch module202and/or resource manager203may be executed as a separate component outside of application manager201or integrated with another component of the operating system. The operating system of system200may be any kind of operating system, such as, for example, iOS™ from Apple®, Android™ from Google®, Windows™ from Microsoft®, or other operating systems (e.g., UNIX, LINUX, real-time or embedded operating systems).

According to one embodiment, each of applications may be executed within a respective dedicated or isolated operating environment, such as a sandboxed environment, and managed by application manager201. For example, application204is launched and executed as a first process within a first sandboxed environment206as a first process address space. Application extension205is launched and executed as a second process within a second sandboxed environment207as a second process address space. A process address space refers to a virtual address space or address space that is the set of ranges of virtual addresses that an operating system makes available to a process. The range of virtual addresses usually starts at a low address and can extend to the highest address allowed by the computer's instruction set architecture. This provides several benefits, one of which is, if each process is given a separate address space, security through process isolation.

Application204may be a content viewing application such as a browser application as a first application, such as Safari™ from Apple Inc.®, Internet Explorer™ from Microsoft®, or Google Chrome™ from Google Inc.® Application extension205may be an plugin of a second application215, such as Adobe Acrobat™ from Adobe System®, where the plugin is specifically designed for the first application to access functionalities of the second application (e.g., container application215). Application extension205and second application215may be developed by a third party and released to the market as a bundle220. When second application215is installed in system200, an application installer (not shown) parses the metadata of bundle215and recognizes that application extension205is designed for application204. Application extension205is then associated with or mapped to application204, for example, in launch database208or in a registry of an operating system. As a result, application extension205may be installed and available to application204to allow application204to invoke application extension205at runtime.

According to one embodiment, application extension205and application204hosting application extension205are loaded and executed in separate process address spaces206-207and treated like separate processes by an operating system. In one embodiment, application204is launched and executed in a first sandboxed environment as a first sandboxed process and the application extension205is launched and executed in a second sandboxed environment as a second sandboxed process. The first sandboxed environment and the second sandboxed environment are configured based on a first security profile209and a second security profile210(which may be as part of launch database208for some or all of applications installed in system200), respectively. Application204and application extension205communicates with each other via an inter-process communications (IPC) framework (not shown), which may be brokered by corresponding extension point225.

According to one embodiment, application204, application extension205, and container application215are executed in their own security contexts. A security context may process resources, security configuration, sandbox environment, and any other measures or policies that ordinarily separates applications from each other. With separate security contexts and the extension framework, the system provides an ability to separately constrain each extension to its minimum needed security profile, for example, using sandboxing, entitlements, and other existing system technologies. Extension point225may be one of various extension points that have been defined by the operating systems. To allow application204and application extension205to communicate with each other, application204and extension205conform to a set of specified policies and/or communications protocol(s) (e.g., APIs) that are specifically designed for extension point225. Thus, application204and application extension205are compiled using an SDK or libraries specifically for extension point225.

The operating system enforces the security and manages resources of application204and application extension205individually or independently based on the first and second security profiles209-210, respectively. Note that second application215, when executed, may be launched in a separate sandboxed environment217, which may be configured based on its respective security context. When application204accesses a functionality provided by application extension205, there is no need to launch container application215as they are treated as separate programs, although application extension205and application215may share the same library or framework during the execution.

A sandboxed process refers to a process that has been isolated within a restricted operating environment (e.g., sandbox) that limits the process to a set of predefined resources. Each sandboxed process may be associated with a set of dedicated system resources, such as, a dedicated memory space, a dedicated storage area, or a virtual machine, etc. One of the purposes of sandboxing an application is to isolate the application from accessing other unnecessary or unrelated system resources of another application or a system component, such that any damage caused by the application would not spill over to other areas of system200.

To provide security, an application may be “contained” by restricting its functionality to a subset of operations, while permitting operations used to perform proper operation, i.e., operation according to its intended functionality. One method to implement a limited set of policies for each application is to contain, or “sandbox” the application. Sandboxing of an application or process can be achieved using operating system level protection to provide containment and to enforce security policies, such as policies that restrict the ability of the application to take actions beyond those functions needed for it to provide its intended functionalities.

When an application has been sandboxed during execution, the application is executed as a sandboxed process or thread within the system that is contained within a sandbox (also referred to as an application container), in which it cannot access certain system resources or another territory (e.g., sandbox) of another application, subject to a security profile associated with the sandboxed application, which is referred to as a sandboxed process or a sandboxed application.

A sandboxed process is the application or other program for which security containment will be implemented. In many cases, a sandboxed process is a user application, but it could be another program implemented on the computing device such as a daemon or a service. To increase security and provide an efficient mechanism, portions of the security system are implemented or executed in a kernel space. In addition, a monitor process module (not shown) is executed in a separate memory space from the sandboxed processes to further insulate them from each other. In particular, a sandboxed process is restricted from accessing memory outside of its process space and is further prohibited from spawning a non-sandboxed process. For example, a security profile of a sandboxed process may include a rule or policy that denies the sandboxed process from using certain system calls, which may be a mechanism that allows processes to alter each other's address spaces.

In some embodiments, a policy may prevent a program from performing certain actions based on the state of an external accessory connected to the computing device, e.g. if an accessory of a specific type or identity is connected; is disconnected, or is connected and is in (or is not in) a specific mode. For example, an application may only be allowed to communicate over an externally accessible data bus if an accessory that meets certain criteria is connected to the data bus and is in a receptive mode. Further detailed information concerning sandboxing techniques are disclosed in U.S. Pat. No. 8,272,048, which is incorporated by reference herein in its entirety.

Referring back toFIG. 2, security profile209specifies a first set of restricted resources that application204can utilize during its operations within process address space206, based on a first security context associated with application204. Similarly, security profile210specifies a second set of restricted resources that application extension205may utilize during its operations within process address space207, based on a second security context associated with extension205. In this example, the second set of resources may be fewer (e.g., more restricted) than the first set of resources. For example, application204may be able to access a network and a local storage of system200, while application extension205may not be able to access the same network, but it may be able to access the local storage of system200.

According to one embodiment, one or more entitlements (e.g., as part of the corresponding security context) are defined for each program or application that is to be deployed in a data processing system. The entitlements represent certain functions or resources that the program is entitled to access during its execution. The entitlements may be specified by a developer during development of the program or alternatively, entitlements can be specified by an authorization entity, such as authorization server or provisioning server, which provisions or distributes the program. Such entitlements may be specified as an attribute or metadata attached to or embedded within the program, and optionally signed by the authorization entity using a digital certificate.

Entitlements can then be used to generate a set of rules specifying certain actions or resources that a program can or cannot do or access during execution of the program. The set of rules are then dynamically compiled, for example, during an installation of the program, into a security profile for the program. During the execution of the program, the security profile is used to enforce the set of rules to restrict the program from performing any action or accessing any resource that the program is not entitled. This in effect forces or contains the program to operate in a restricted operating environment (e.g., a sandbox or sandboxed environment). Resources refer to any kind of resources in a data processing system or electronic device, such as, for example, memories, inputs/outputs (IOs), buses, storage, files, network connections (e.g., sockets, ports, or network addresses), inter-process communications channels (e.g., UNIX domain sockets, XPC, MACH ports), etc.

Restricting execution of a program within a restricted operating environment can reduce the changes of the program interfering or causing damages to other components or resources of an electronic device. For example, a program may be developed by a third party and downloaded from a network. The program may include a malfunctioning component or routine (e.g., programming bugs), which may accidentally access certain critical memory space that is normally exclusively utilized by an operating system, microprocessor, bus, or other components of the electronic device. Such actions may cause the electronic device to crash. Alternatively, a program may be a malicious program that is developed to intentionally cause damage to an operating environment and/or electronic device. For example, a program with virus may be specifically developed to take control of the electronic device and/or steal confidential information of a user that operates the electronic device. By restricting the execution of a program within a restricted operating environment, such damage can be greatly reduced.

Referring back toFIG. 2, in this example, by executing application204and application extension205in separate process address spaces206-207, security of application204and application extension205can be independently enforced and managed. The malfunction of one entity (e.g., application extension205) would not cause much damage of the other (e.g., application204). In addition, resources associated with application204and application extension205can be efficiently managed. For example, if application extension205is no longer needed by application204, application extension205can be individually terminated or unloaded, and its resources can be released back to a resource pool for other usages without significantly affecting the operations of application204.

FIG. 3is a diagram illustrating an example of architecture of an operating system according to one embodiment of the invention. Operating system300may be implemented as part of system200ofFIG. 2. Referring toFIG. 3, operating system300includes, amongst others, a set of one or more extension points303-305to allow various clients, such as clients301-302, access via extension points303-305. Each of extension points303-305represents a set of predefined APIs or protocols to allow one client as a host application to obtain a predefined service or services provided by another client as an extension that extends at least a portion of functionalities of another application as a container application. Each of extension points303-305may further define the resources, scheduling, and termination (e.g., which of the process should be terminated first, etc.) schemes for the processes associated with the extension point. In one embodiment, extension points303-305may include various commonly used or popular functionalities or services associated with operating system300. An extension point defines a set of predefined application programming interfaces (APIs) or communications protocols that allow a client to access or to provide a service from and to another client. A service provided by an extension point may be provided by a standard component of the operating system or a third party function provided by a third party vendor.

Extension points303-305may be managed by extension manager310, where extension points303-305may be collectively referred to as an extension interface or extension layer as part of system component of operating system300. When extension302, as well as, its corresponding container application (not shown), is installed, installation module320parses metadata of an application bundle containing extension302and its container application. Based on the metadata associated with extension302, installation module320recognizes that extension302is specifically designed and developed for extension point304. For example, extension302may be developed using a specific extension template and compiled with a specific set of libraries corresponding to extension point304.

Installation module320then installs extension302in operating system300and stores any information related to extension302in launch database208. For example, a security profile (e.g., configuration file) of extension302may be compiled and stored in launch database208. The security profile may include information indicating that extension302is capable of providing a service or services through extension point304. The security profile may further include resource entitlements or restrictions that may be subsequently utilized to configure a sandboxed environment when extension302is launched. Other extensions may be installed in a similar way by installation module320.

Subsequently, when a client, in this example, application301, inquires by communicating via extension304about a service available for extension point304, extension manager310invokes launch module202(or discovery module, not shown) to discover any extensions installed in the system that are capable of providing the inquired service. In response, launch module202searches within launch database208to identify and determine which of the installed extensions are capable of providing such a service. In one embodiment, the inquiry may include information specifying certain specific resources that are required for the service. In response, launch module202searches and identifies those who can handle the specified resources. For example, a host application may specify the data size that a service is required to handle. Thus, the extension framework as shown inFIG. 3is able to match the capabilities of extensions with the specification of the requested services.

If there is only one extension installed capable of providing services for extension point304, launch module202may automatically launch the identified extension. If there are multiple extensions that are capable of providing services for extension point304, launch module may present a list of the extensions to allow a user or client301to select one of them for launching. If there are multiple versions of the same extension installed, at least some of the versions may be presented to the user or alternatively, the latest version may be presented. Once the selected extension, in this example, extension302, has been launched, extension manager310invokes IPC service module315to facilitate IPC communications between client301and client302via extension point304. In one embodiment, the communications between client301and client302are asynchronous message based communications, such as the XPC framework available from Apple Inc. In one embodiment extension points303-305may include, but are not limited to, an extension point for the notification center of operating system300, an extension point for a third-party keyboard, an extension point for social media, an extension point for services with a user interface (UI), an extension point for a file provider/picker, an extension point for photo editing and/or filtering, an extension point for translation, and an extension point for a file/content finder.

Extension manager310of the extension framework as shown inFIG. 3is configured not to enable “generic” communication between applications and their extensions. Instead, it requires specific extension points303-305narrowly tailored for a particular functional purpose. This is important to formalize the data and control flow between them, making it less likely for either to be able to extend a security exploit into the other. Essentially, each extension point is a well-designed conduit for extending a suitable application. According to one embodiment, the security contexts are individually assigned to extensions as they are used by extension manager310(e.g., one-to-one relationship). Alternatively, the security contexts may be reused, and in some situations multiple (compatible) extensions can share a security context.

In one embodiment, each of extension points303-305includes at least two sets of APIs, one for host applications to invoke extension services and the other for extensions to provide extension services, as shown inFIG. 4. Referring toFIG. 4, since client301and client302are executed separate sandboxed environments, they normally cannot directly communicate with each other. Rather, client301, as a host application in this example, communicates using a first set of APIs or protocols associated with extension point400to access system resources such as extension manager310, launch module202, and IPC service module315, etc. Similarly, client302, as an extension in this example, communicates using a second set of APIs or protocols associated with extension point400to access extension manager310, launch module202, and IPC service module315. In order to access extension point400, client301and client302may be compiled and linked using an SDK that is associated with extension point400during the software development.

According to one embodiment, an extension point acts as an interface for a software developer for an extension and provides a domain that the extension operates. Each extension point is associated with a predefined set of policies (e.g., resource entitlements or restrictions) and specifies what messages can be exchanged between the host application and the extension. All extensions designed for a particular extension point must comply with the specification set forth in the predefined policies of that particular extension point. All extensions, when executed in an operating environment, are entitled to or restricted by the same set of operating environment parameters defined by the associated extension point.

When the extension of the second application is developed, as shown inFIG. 5, a developer can utilize an extension template501associated that particular extension point as part of a software development kit (SDK) to generate, based on source code502, executable images of both a container application531and the associated extension532, as well as their respective metadata533-534. The extension and the container application may be released as bundle220. The bundle includes the container application531and its metadata533describing the container application, and the extension532and its metadata534describing the extension. However, the container application531and the extension532can each be launched in a separate sandboxed environment and operated independently, which may be configured based on one or a combination of their respective metadata or the corresponding extension point, although they may access or share a common library or framework. In some embodiments, a container application may include multiple extensions, in this example, extensions541and542.

An application bundle may be a directory that allows related resources, such as software code, to be grouped together. An application bundle may be identified by the “.app” extension (e.g., “application.app”). An application bundle may include a number of directories and/or subdirectories, such as “Contents,” “Operating system,” which may contain the application's executable code, identified, for example, by the “.exe” extension (e.g., “Application.exe,” however in other embodiments, the executable file may have another extension or may not include an extension), “Resources,” which may contain resources of the application (e.g., “Image.png”), and “XPC services,” which may contain application defined services. These services may be a set of computer implemented instructions designed to implement a specific function or perform a designated task. In one embodiment, the application defined services are services which are available only to the application represented by the application bundle. In addition, these application defined services may be tied to the lifetime of the application, in that once the application is terminated, the service is no longer available.

In one embodiment, the executable code in an application bundle may link against one or more frameworks. Frameworks may include software libraries having reusable abstractions of software code wrapped in a well-defined application programming interface (API). The frameworks allow software developers to implement the standard structure of an application for a specific development environment (e.g., the operating system running on the computing device). The frameworks linked against by an application may be represented by framework bundles. Some examples of commonly used frameworks include a core audio framework and a core graphics framework. The executable files in an application may link against the frameworks by storing a framework name or other identifier of framework bundles in a designated location in the application bundle and/or by calling an API provided by the associated framework.

The services included in the framework bundles may be made available to a number of different applications that are all linking against the same framework. In one embodiment, there may be a single global instance of a particular service in a framework that is available to a certain number of different applications. In another embodiment, there may be an individual instance of a particular service that is instantiated for each user of the system, or an instance of the service for each application that is running in the system. In other embodiments, each service may have a different designation as a global instance, a per-user instance, or a per-application instance, where there may be services of each type present at the same time in the same or different framework(s). In addition, some other instance may be created at the discretion of the framework. For example, one framework may have one instance for each browser tab or window that is opened. Each instance may be identifiable by a universal unique identifier (UUID).

At the time an application is built, the application designer may specify what services are defined specifically in the application, as well as what frameworks the application will link against. The application designer may also have knowledge of what services are contained within those frameworks. Thus, between the application defined services and the services in linked frameworks, the application designer is able to grant access to all of the services that the application executable file needs or may be likely to access. In addition, the application designer is able to specify which services the application executable file is allowed to access. Therefore, unnecessary and unauthorized services are not made available to the application. This information, in a form of metadata, may eventually be compiled as a part of entitlements of a security profile associated with the application.

Referring back toFIG. 5, for at least one of the extension points associated with an operating system, an extension template (e.g., template501) may be defined to allow a software developer to have a simple and user friendly user interface to construct source code (e.g., source code502) for that particular extension point. For example, an extension template may be associated with a set of predefined certain objects or classes that are typically required to access the associated extension point, either from a point view of a host application or from a point of view of an extension. The extension template may further identify a set of libraries or frameworks that are specifically associated with the extension point. Thus, when an SDK tool, such as a compiler and/or linker, of SDK510compiles source code502, the relevant libraries or frameworks, such as libraries520, are utilized. As a result, all extensions compiled for the same extension point will be compatible with the same set of APIs or protocols and entitled to the same resource entitlements or limited to the same restrictions of an operating environment during execution.

In one embodiment, the developers package one or more extensions with (physically inside of) a containing application. This allows users to view them as a logical part (provided by) the containing application, even though architecturally they are separate and (by default) fully isolated from each other. This also allows the operating system to have full context isolation without burdening the user with the need to understand this architecture. In one embodiment, the operating system is able to deliver extensions not associated with applications, and the user sees those as “part of the system components.”

FIG. 6is a flow diagram illustrating a method for developing extensions for extension points according to one embodiment of the invention. Method600may be performed by processing logic which may include software, hardware, or a combination thereof. For example, method600may be performed by SDK510ofFIG. 5. Referring toFIG. 6, at601, a set of extension points is defined. Each extension point is associated with a set of APIs to allow one application to access a predefined functionality or obtain a service, which may be extended from another application (e.g., container application) via an extension. At602, a container application is compiled including generating a first configuration file defining resource entitlements for the container application. At603, an extension that extends a functionality of the container application to another application via a specific extension point is compiled, including generating a second configuration file having metadata associated with that extension point. At604, the container application and the extension, as well as their respective configuration files are packaged into a bundle for installation. The container application and the extension can be launched in different sandboxes independently.

FIG. 7is a flow diagram illustrating a method for managing extensions via extension points according to one embodiment of the invention. Method700may be performed by processing logic which may include software, hardware, or a combination thereof. For example, method700may be performed by operating system300ofFIG. 3. Referring toFIG. 7, at701, processing logic receives a request from a first application inquiring any service associated with a particular extension point extended by one or more other applications. In response to the request, at702, processing logic identifies a list of one or more extensions installed and capable of providing the requested service via that particular extension point. At703, the list of identified extensions is presented to a user or to the first application for selecting one of the extensions. At704, in response to a selection of an extension that extends a functionality of a second application, processing logic launches the extension in a separate sandboxed environment. Note that the extension can be independently executed without having to launch the second application. At705, resource restriction associated with the extension point is enforced on the extension via the corresponding sandboxed environment.

As described above, examples of extensions include, but are not limited to, an extension point for the notification center of operating system300, an extension point for a third-party keyboard, an extension point for social media, an extension point for services with a user interface (UI), an extension point for a file provider/picker, an extension point for photo editing and/or filtering, an extension point for translation, and an extension point for a file/content finder. Some of these extensions, such as a translation extension point or a filtering extension point, are referred to as action extension points. According to one embodiment, an action extension may include piece of executable code, such as JavaScript or other scripts that can be invoked and downloaded from the extension, and executed within the host application to help certain tasks of the host application.

FIG. 8is a diagram illustrating an example of an action extension point according to one embodiment of the invention. Referring toFIG. 8, action extension802, in this example, is a content processing extension that is designed to process content or data for a client such as host application801via action extension point810. Action extension802may be developed by a third-party developer that is different than the one providing the operating system. In one embodiment, action extension802includes data conversion code804A in addition to content processing function or module805. Data conversion code804A, as a helper agent, may be implemented in a form of executable script, such as JavaScript™.

In one embodiment, when host application801requests an action extension service, for the purpose of illustration, a translation extension service, action extension point810(e.g., translation extension point) identifies and launches extension802to provide translation services. In addition, host application801may invoke data conversion code804A to perform certain data conversion before content processing module805performs the actual translation. In one embodiment, host application801, in this example, a browser application, downloads data conversion code and executed within host application801as data conversion code804B.

Data conversion code804B, when executed, is configured to parse content803to identify which portion of content803needs to be processed by content processing module805. Data conversion code804B packages the identified content to a format compatible with extension point810and sends the packaged data to extension802to be processed by content processing module805, in this example, a translation module to translate content. In response to the result of the content processing, i.e., translated content, data conversion code804B is to reformat the translated content to be compatible with content803and incorporates the translated content with content803.

This embodiment can be applied to the situation which host application801is a browser application displaying certain content803as a hypertext markup language (HTML) page. The browser application can download the JavaScript, i.e., data conversion code804A and execute it as code804B. The JavaScript can then process the HTML content803to parse and understand the HTML page in order to identify the interested data to be translated. As a result, content processing module does not have to understand the structure of the HTML page. Data conversion code operates as a helper agent for extension802(similar to an extension of another extension). Note that data conversion code804B still communicates with extension802via extension point810. Data conversion code804A is bundled within extension802, but it is downloaded and executed by host application801as code804B.

FIG. 9is a flow diagram illustrating a method performed by an action extension point according to one embodiment of the invention. Method900may be performed by processing logic which may include software, hardware, or a combination thereof. For example, method900may be performed by the system as shown inFIG. 8. Referring toFIG. 9, at901, in response to a request from a host application to invoke a content processing service (e.g., translation), processing logic identifies and loads a content processing extension. The host application may browser application displaying a Web page and the extension may be a translation extension providing translation services. At902, processing logic downloads data conversion code from the extension and loads the data conversion code within the host application. The data conversion code may be an executable script such as JavaScript. At903, the host executes the data conversion code to parse and identify a portion of the content presented by the host application. At904, the data conversion code converts the identified portion of the content to a form compatible with a corresponding extension point (e.g., translation extension point) and sends the converted data to the extension via the extension point. In response to the processed content (e.g., translated content) received from the extension, the data conversion code is to convert the data back to the form compatible with the host application and incorporate the processed content with the existing content of the host application.

FIG. 10is a flow chart depicting a method of providing an application extension service to a host application executing on a client device in accordance with some embodiments. A host application executing on a client device, such as a content viewing application, displays1001displays one or more content items loaded based on received user input. In one implementation, the host application is a browser application that includes a user interface for receiving a user input specifying a source for content items and a display presenting retrieved content items. The user interface also includes a menu bar or other suitable interface object for invoking other functionality provided by the browser.

In one embodiment, the user interface of the host application includes an interface for selecting a content activity interface to access one or more content processing extensions. Responsive to detecting1002an input to active the activity interface, the host application displays a list of content processing extensions discovered by the host application as described in conjunction withFIG. 3. In one implementation, the activity interface is a share sheet that includes content processing extensions associated with container applications that provide functionality that allows content items provided by the host application (e.g., browser application) to be shared with other users while a user interacts with the host application using the client device. The activity interface input includes a touch contact with a portion of a display included in the client device, a selection via a user interface element of a host application, or other types of interaction with the activity interface included user interface of the host application. In one implementation, the list of content processing extension includes one or a combination of social extensions and services with user interface extensions selectable by a user. In another implementation, the activity interface includes a list of functions or actions, each function or action corresponding to a particular content processing extension. When a content processing extension is selected1003from the list of content processing extensions, the host application sends a request to the content processing extension to invoke a content processing service associated with the selected content processing extension. In one implementation, the content processing service is a translation service as described in conjunction with901ofFIG. 9. In other implementations, the content processing service includes one of social networking service, messaging service, or other service provided by a container application associated with the selected content processing extension.

The host application downloads data conversion code from the extension and loads the data conversion code within the host application as described in conjunction with902ofFIG. 9. In one implementation, the data conversion code is an executable script such as JavaScript that perform operations including scraping a web page written in HTML for content items to provide to a container application, such as a social networking application executing on the client device. The executable script can be embedded in the extension. In other implementation, the scripting language of the data conversion code is written in a language suitable to identify, modify, or otherwise interact with content items provided by the requesting host application. The data conversion code executing within the host application identifies1005a set of content items presented by the host application and converts the identified content items to a form compatible with a corresponding extension point. For example, in one implementation, the data conversion code converts the identified content items to a JavaScript literal object. In other embodiments, the data conversion code converts the identified content items in another format in accordance with the specifications of the container application associated with the selected content processing extension.

The data conversion code sends1006the formatted content items to the selected content processing extension for processing via the extension point as described in conjunction with904ofFIG. 9. The selected content processing extension and the associated container application may be launched in a separate sandboxed environment and operated independently as described in conjunction withFIGS. 2, 5, and 6, thereby restricting execution of the content processing extension within a restricted operating environment to reduce the likelihood of the content processing extension interfering or causing damages to other components or resources of the client device.

The content processing extension receives the processed content items and sends the processed content items to the requesting host application for display on the client device. In one embodiment, the processed content items include one or more content items obtained from the host application and a user interface provided by the container application. In one example, the content item is an article or news story and the user interface is a sharing interface for a social networking application. In one embodiment, the host application generates1007a page that includes the processed content items received from the content processing extension for display to on the client device. In another embodiment, the host application generates1007a page that includes the processed content items display in a portion of the user interface of the host application and additional content items not processed by the content processing extension in another portion of the user interface.

FIG. 11is a diagram illustrating an example of a data processing system which may be used in accordance with some embodiments. For example, system1100may represents any of data processing systems described above performing any of the processes or methods described above. For example, system1100may represent systems as described above inFIGS. 2-5 and 8. System1100may represent a desktop (e.g., iMac™ available from Apple Inc. of Cupertino, Calif.), a laptop (e.g., MacBook™), a tablet (e.g., iPad™) a server, a mobile phone (e.g., iPhone™), a media player (e.g., iPod™ or iPod Touch™), a personal digital assistant (PDA), a personal communicator, a gaming device, a network router or hub, a wireless access point (AP) or repeater, a set-top box, or a combination thereof.

Referring toFIG. 11, in one embodiment, system1100includes processor1101and peripheral interface1102, also referred to herein as a chipset, to couple various components to processor1101including memory1103and devices1105-1108via a bus or an interconnect. Processor1101may represent a single processor or multiple processors with a single processor core or multiple processor cores included therein. Processor1101may represent one or more general-purpose processors such as a microprocessor, a central processing unit (CPU), or the like. More particularly, processor1101may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, or processor implementing other instruction sets, or processors implementing a combination of instruction sets. Processor1101may also be one or more special-purpose processors such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, a graphics processor, a network processor, a communications processor, a cryptographic processor, a co-processor, an embedded processor, or any other type of logic capable of processing instructions. Processor1101is configured to execute instructions for performing the operations and steps discussed herein.

Peripheral interface1102may include memory control hub (MCH) and input output control hub (ICH). Peripheral interface1102may include a memory controller (not shown) that communicates with a memory1103. Peripheral interface1102may also include a graphics interface that communicates with graphics subsystem1104, which may include a display controller and/or a display device. Peripheral interface1102may communicate with graphics device1104via an accelerated graphics port (AGP), a peripheral component interconnect (PCI) express bus, or other types of interconnects.

An MCH is sometimes referred to as a Northbridge and an ICH is sometimes referred to as a Southbridge. As used herein, the terms MCH, ICH, Northbridge and Southbridge are intended to be interpreted broadly to cover various chips who functions include passing interrupt signals toward a processor. In some embodiments, the MCH may be integrated with processor1101. In such a configuration, peripheral interface1102operates as an interface chip performing some functions of the MCH and ICH. Furthermore, a graphics accelerator may be integrated within the MCH or processor1101.

Memory1103may include one or more volatile storage (or memory) devices such as random access memory (RAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), static RAM (SRAM), or other types of storage devices. Memory1103may store information including sequences of instructions that are executed by processor1101, or any other device. For example, executable code and/or data of a variety of operating systems, device drivers, firmware (e.g., input output basic system or BIOS), and/or applications can be loaded in memory1103and executed by processor1101. An operating system can be any kind of operating systems, such as, for example, Windows® operating system from Microsoft®, Mac OS®/iOS® from Apple, Android® from Google®, Linux®, Unix®, or other real-time or embedded operating systems such as VxWorks.

Peripheral interface1102may provide an interface to IO devices such as devices1105-1108, including wireless transceiver(s)1105, input device(s)1106, audio IO device(s)1107, and other IO devices1108. Wireless transceiver1105may be a WiFi transceiver, an infrared transceiver, a Bluetooth transceiver, a WiMax transceiver, a wireless cellular telephony transceiver, a satellite transceiver (e.g., a global positioning system (GPS) transceiver) or a combination thereof. Input device(s)1106may include a mouse, a touch pad, a touch sensitive screen (which may be integrated with display device1104), a pointer device such as a stylus, and/or a keyboard (e.g., physical keyboard or a virtual keyboard displayed as part of a touch sensitive screen). For example, input device1106may include a touch screen controller coupled to a touch screen. The touch screen and touch screen controller can, for example, detect contact and movement or break thereof using any of a plurality of touch sensitivity technologies, including but not limited to capacitive, resistive, infrared, and surface acoustic wave technologies, as well as other proximity sensor arrays or other elements for determining one or more points of contact with the touch screen.

Audio IO1107may include a speaker and/or a microphone to facilitate voice-enabled functions, such as voice recognition, voice replication, digital recording, and/or telephony functions. Other optional devices1008may include a storage device (e.g., a hard drive, a flash memory device), universal serial bus (USB) port(s), parallel port(s), serial port(s), a printer, a network interface, a bus bridge (e.g., a PCI-PCI bridge), sensor(s) (e.g., a motion sensor, a light sensor, a proximity sensor, etc.), or a combination thereof. Optional devices1108may further include an imaging processing subsystem (e.g., a camera), which may include an optical sensor, such as a charged coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) optical sensor, utilized to facilitate camera functions, such as recording photographs and video clips.