# Patent

## Title
Systems and methods for persisting data between web pages

## Abstract

The described systems and methods are directed at persisting data between web pages. A server receives object-related data associated with a first web page and a request for posting to a second web page from a client. The object-related data includes information about the objects in the first web page. Instances of the objects associated with the first web page are reconstructed based, at least in part, on the object-related data. The server generates rendering data of the second web page based, at least in part, on the reconstructed object instances. In this manner, the object-related data is allowed to persist from the first web page to the second web page.

## Background
TECHNICAL FIELD
This systems and methods discussed herein relate to web content management.
BACKGROUND OF THE INVENTION
In the past, pages in the World Wide Web (Web) essentially contain only static content written in procedural codes using hyper text markup language (HTML). These web pages are stored on servers connected through the Internet. Each web page is associated with a uniform resource locator (URL) and a user/client can browse to a particular web page by requesting the web page from a server using the URL corresponding to the page. Some traditional web pages allow users to post data to another page using standard HTML input methods, such as forms. To post the data, a user must activate a trigger (e.g. a button) on the page to send the data to a process on the server, such as a common gateway interface (CGI) program. Particularly, the data is appended to the end of the URL associated with the process. The process may use the submitted data to generate another page.
The methods of posting data on traditional web pages have many deficiencies. For example, although a user can post data to a server, the data can only include actual values as part of the request or appended to the end of a URL as a text string. This method of posting data lacks the ability to send complex objects that cannot be properly represented by plain text. Also, the “posted to” web page must be regenerated for each post request. So, if a programmer would like to use input from the user on a particular web page to generate content on another related web page, the programmer must create a process to parse the web request or URL for the actual values submitted by the user on the original web page and to generate the other web page using the submitted values, without having the abilities to reuse features and complex data objects on the original web page.
Thus, there is a need for an efficient technique to persist data between web pages that does not require the storage of a large amount of data on the server for each web page and the complete regeneration of a web page in response to a posting request.
SUMMARY OF THE INVENTION
The systems and methods described herein are directed at persisting data between web pages. A server receives user inputs and object-related data associated with a first web page and a request for posting to a second web page from a client. The object-related data includes information about the objects in the first web page. Instances of the objects associated with the first web page are reconstructed based, at least in part, on the object-related data and user inputs. The server generates rendering data of the second web page based, at least in part, on the reconstructed object instances. In this manner, the object-related data is allowed to persist from the first web page to the second web page.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a system for persisting data between web pages.
FIG. 2 is a schematic diagram of the server shown in FIG. 1.
FIG. 3 is a schematic diagram of example data associated with an example web page sent by a server to a client.
FIG. 4 is a schematic diagram of example data associated with another example web page.
FIG. 5 is a flow diagram of an example process for a server to process a web page request from a client.
FIG. 6 is a flow diagram of an example process for a server to obtain information about a previous web page for processing a post to a requested web page.
FIG. 7 illustrates an example computing device within which the described systems and methods can be either fully or partially implemented.



DETAILED DESCRIPTION
The systems and methods described herein provide an efficient technique to persist data between web pages. Each web page includes objects that may have various configurations, such as properties, states and behaviors. A server determines object-related data for representing the configurations of the objects in the web page and sends the rendering data for the web page and the object-related data to the requesting client. The client may post from the original web page to another web page with input data. Posting from a first web page to a second web page means that an operation which client causes a call from first web page to the second web page on the server. For example, the client may issue to the server a request for the other web page along with posting data and the object-related data associated with the original web page. The server may instantiate the original web page using the object-related data to obtain the information from the original web page when generating the second web page. In this manner, object-related data may persist between web pages without being saved on a server. These and other aspects will be discussed in more detail in the description below.
FIG. 1 is a schematic diagram of a system 100 for persisting data between web pages. System 100 may include client 105 and server 110. Client 105 and server 110 may include any type of computing device, such as desktop and laptop computers, dedicated server computers, network appliances, personal digital assistant (PDA) devices, wireless phones, pagers, and the like. Client 105 is configured to enable users to request web pages. For example, client 105 is also configured to send a request 115 for a web page to server 110 and to render the web page for the users using data received from server 110. Particularly, the client 105 is configured to receive rendering data 120 for the requested web page and object-related data 151 from server 110. Object-related data 151 includes information about the objects in the requested web page. For example, object-related data 151 may include the configurations of the objects, such as states, properties and behaviors. Client 105 is configured to maintain object-related data 151. In response to a request to post to another web page from the original web page, client 105 is also configured to issue a request 130 to server 110 for the other web page along with object-related data 151. Request 130 may also include client input data 133 posted from the original web page.
Server 110 is configured to receive requests for web pages from client 105. Server 110 will be discussed in more detail in conjunction with FIG. 2. Briefly stated, server 110 generates web pages requested by client 105 using various objects. For example, server 110 may generate a particular web page by incorporating instances of the objects related to the web page and assigning the proper configurations, such as states, properties and behaviors, to those objects. Server 110 also creates object-related data associated with the objects. Server 110 is configured to send rendering data associated with the web page and the corresponding object-related data to the client.
Example communications between server 110 and client 105 will now be discussed in conjunction with FIG. 1 to further illustrate system 100 in operation. As shown in FIG. 1, client 105 issues a request 115 for Page A to server 110. The request may include the address of Page A, such as a uniform resource locator (URL). In response, server 110 generates rendering data for Page A 120 by incorporating various objects in the web page. Server 110 also creates object-related data 151, which includes information about the objects in Page A. Page A is configured to post to Page B under certain conditions, such as a user input. Server 110 then sends rendering data 120 and object-related data 151 to client 105.
Upon receiving rendering data 120 and object-related data 151 from server 110, client 105 may render Page A, such as displaying the page to a user. Client 105 may determine to post from Page A to Page B. For example, client 105 may receive a user input in Page A that causes a post to Page B. In response, client 105 issues a request 130 for Page B to server 110 along with object-related data 151 received from server 110. Client 105 may also include information about the user input in the request 130.
In response to receiving request 130 and object-related data 151, server 110 instantiates Page A using object-related data 151. For example, server 110 may reconstruct instances of objects in Page A 120 using object-related data 151. The reconstructed object instances include the configurations specified in object-related data 151. Server 110 may generate rendering data for Page B using the reconstructed objects in Page A and other objects not associated with Page A. Server 110 determines object-related data 153, which includes information about the objects in Page B. Server 110 then sends rendering data 140 and object-related data 153 to client 105.
It is to be appreciated that object-related data 151 persists from Page A to Page B without being saved in server 110. Persisting object-related data in this manner allows a web page to efficiently post to another web page, without requiring data storage on the server. This technique of persisting data also enables an original web page generated by one server to post to a requested web page generated by a second server while allowing the second server to access information about the objects in the original web page. The arrangement of multiple servers being configured to provide related web content is often referred to as a web farm. Typically, servers in a web farm have the necessary applications installed on them to implement the described technique.
FIG. 2 is a schematic diagram of server 110 shown in FIG. 1. As shown in FIG. 2, server 110 may include page producer 204, object data manager 206, and data store 208. The components in FIG. 2 are shown for illustrative purposes. In actual implementation, server 110 may include more, less, or different components than those shown in FIG. 2.
Data store 208 provides storage for information that is used by server 110 to generate web pages. Data store 208 may be implemented in any type of volatile or persistent memory device, such as random access memory (RAM), flash memory, optical or magnetic disk drive, hard drive, and the like. The information in data store 208 includes objects 210, which include both data and procedures for manipulating the data. Objects 210 are typically used by page producer 204 to generate web pages in an object-oriented manner. Web pages that are generated using objects 210 are more efficiently created than procedural based web pages. Such object-oriented web pages may also efficiently include dynamic content that is generated and updated in a real-time manner in response to requests. For example, objects 210 may be individually updated and incorporated in a web page, without changing other objects in the page. Web pages that are dynamically generated in such a manner provide a better user experience than web pages with only static content.
Page producer 204 is configured to provide web pages specified in requests from clients to server 110. To provide an enhanced user experience, page producer 204 may be configured to dynamically generate the requested web pages. Page producer 204 may generate web pages with objects 210 in data store 208. For example, page producer 204 may incorporate instances of objects 210 in the web page. Page producer 204 is configured to assign the appropriate configurations to objects 210 for incorporation. To enable program developers to construct web pages that provide a more cohesive user experience, page producer 204 is also configured to generate a web page that posts to other web pages.
Page producer 204 may also be configured to obtain information from other computers 220 to generate web pages. For example, a requested web page may include updated information that is provided by another server. Page producer 204 may obtain the information from another server in real time and dynamically generate the requested web page with the obtained information.
Object data manager 206 manages object-related data for server 110. Object data manager 206 is configured to determine object-related data associated with objects that are used by page producer 204 to generate a web page. For example, page producer 204 may include control objects in a particular web page. In response, object data manger 206 determines viewstate data related to the configurations of the control objects, such as their properties, states and behaviors. The viewstate data is sent by page producer 204 to the requesting client along with the rendering data for the web page.
Object data manager 206 is also configured to instantiate a web page from object-related data associated with the web page. Object data manager 206 typically instantiates a particular web page to obtain information for generating another web page posted from the original web page. Instantiating a web page includes reconstructing instances of objects in the web page using object-related data. For example, if the object-related data includes viewstate data associated with control objects in the original web page, object data manager 206 will reconstruct the control objects with the configurations specified in the object-related data. Page producer 204 may then use the reconstructed object instances to create the other web page posted from the original web page.
To enhance security, object data manger 206 is configured to use a message authentication code (MAC) to protect object-related data. A MAC is a secret key that is used to uniquely identify a message. A MAC may be uniquely assigned to a particular message or be derived based on the properties of the message. A MAC may be used in conjunction with an encryption mechanism to provide multiple layers of security. For example, object data manger 206 may encrypt object-related data using a hash function with a MAC as the encryption key. The MAC may be also included as part of the encrypted object-related data. Object data manger 206 is configured to use the MAC in the object-related data to determine whether the data is valid. For example, object data manager 206 may use a particular MAC to decrypt the object-related data. The decrypted object-related data includes a second MAC. If the first MAC and the second MAC do not match, the object-related data has likely been tempered and object data manger 206 would determine that the data is invalid.
Object data manger 206 is also configured to serialize object-related data for sending to the client. Object data manger 206 may serialize the object-related data in accordance with hyper text transfer protocol (HTTP) and send the serialized data to the client in an HTTP hidden field.
FIG. 3 is a schematic diagram of example data associated with an example web page 300 sent by a server to a client. Example object-related data 350 is typically sent by the server in response to a request for example web page 300 issued by the client. Example web page 300 is related to a customer survey and includes selection control object 305, textbox control object 306 and checkbox control object 307. Object-related data 350 associated with web page 300 is sent from the server to the client along with rendering data for web page 300. As shown in FIG. 3, object-related data 350 includes selection control viewstate data 343, textbox control viewstate data 344 and checkbox control viewstate data 345. Viewstate data 343-345 are data about the configurations of control objects 305-307 in web page 300. For example, viewstate data 343-345 may include the layout, the selection choices and mechanisms, and the associated text for control objects 305-307. Object-related data 350 may include a message authentication code (MAC) 380 for security purposes. Object-related data 350 may also be encrypted with an encryption key, such as MAC 380.
Web page 300 may include submit button 320 that is configured to post input data to the next web page. In response to activating the submit button, the client sends the input data associated with control objects 305-307 to the server along with an address for the next web page and object-related data 350. The server may then use the input data and object-related data 350 to generate the next web page specified by the address.
FIG. 4 is a schematic diagram of example data associated with another example web page 400. Example object-related data 450 is typically sent by the server to the client in response to a post from the original web page 300 shown in FIG. 3. Example web page 400 is another page of the customer survey and includes selection control objects 405 and 406, checkbox control object 407, and textbox control object 408.
The server typically receives an address for web page 400 from the client along with input data from the original page 300 and object-related data 350. The server may instantiate web page 300 using object relate data 350 to obtain the configurations of the objects in web page 300. The server may then use the data from the instantiation and the input data to generate web page 400. The server may generate selection control objects 405 based on reconstructing selection control object 305 from selection control viewstate data 343. For example, the server may generate selection control object 405 to include a default selection of “Word Processor”, which is included in the input data. In this manner, the server efficiently incorporates selection control object 405 in web page 400 that is consistent with selection control object 305 in web page 300.
In a similar manner, the server may generate control objects 406-408 based on instantiating control objects 305-307 using object-related data 305 and input data. For example, the server may simply use the configurations of control object 305-307 to generate control objects 406-408. The server may then generate object-related data 450 that includes viewstate data 461-464. Object-related data 450 may include a MAC 480, which may or may not be identical to MAC 380 in web page 300.
FIG. 5 is a flow diagram of an example process 500 for a server to process a web page request from a client. At block 505, a request for a web page is received. The request typically includes an address for the web page. If the request is a post from a previous web page, the request may also include input data and viewstate data associated with control objects in the previous page. At block 510, the requested web page is initialized. At decision block 515, a determination is made whether the request is a post from a previous web page. If so, process 500 moves to block 517 where data about the objects in the previous page is obtained, which will be discussed in more detail in conjunction with FIG. 6. Process 500 then continues at block 520.
Returning to block 515, if the request is not a post from another web page, process 500 moves to block 520 where data associated with the requested web page is loaded. For example, instances of objects that are used to create the requested web page are generated. At block 525, the web page is processed, which may involve performing any updates to the objects in the web page through a set of page lifecycle events before the output of the web page is rendered.
At block 530, the configurations of the control objects in the web page are saved as viewstate data associated with the web page. At block 535, rendering data for the web page is generated. At block 540, the rendering data and the viewstate data are sent to the client.
FIG. 6 is a flow diagram of an example process 600 for a server to obtain information about a previous web page for processing a post to a requested web page. At block 605, the access permission for the previous web page from which the post was originated is checked. The access permission may be associated with a posting client or a particular user associated with the client.
At decision block 610, a determination is made whether permission has been granted to access the previous web page. If no permission exists or if the previous page does not exist, process 600 goes to block 612 where an error message is returned.
Returning to decision block 610, if permission exists, the process moves to block 620 where a first message authentication code (MAC) is computed from the viewstate data. At block 625, a second MAC within the viewstate data is determined. At decision block 630, a determination is made whether the computed MAC and the determined MAC match. If the MAC's do not match, process 600 goes to block 612 where an error message is returned.
Returning to decision block 630, if the MAC's match, process 600 moves to block 633 where the previous web page is instantiated using the viewstate and user input data associated with the post. For example, the instances of the control objects in the previous page are reconstructed and configured using the user input and viewstate data. At block 635 where programmatic access to the control objects associated with the previous web page is obtained.
Example codes are discussed below to further illustrate how the described systems and methods can be implemented.







TABLE 1





Example code for posting a page.

















<form runat=“server”>









<asp:TextBox id=“TextBox1” runat=“server” />



<br>



<asp:Button runat=“server” Text=“Causes PostBack”









/>









<br>



<asp:Button runat=“server” Text=“Cross Page Post”









PostBackUrl=“Page2.aspx” />



</form>









Table 1 shows an example code section for posting from an original web page to another web page (i.e. page2.aspx). For controls that are configured to post to the other web page, the PostBackUrl property on the button in Table 1 causes the form's action attribute to be set via JavaScript to the appropriate URL for HTML devices that support JavaScript. In the example code in Table 1, button controls are used. One of controls sets the new PostBackUrl property, which causes the original web page to perform an HTTP POST to Page2.aspx when the button is clicked.







TABLE 2





An example page configured for cross-page post.

















<script runat=“server”>



 public DropDownList SelectedCountry {









get {









return Country;









}









 }



</script>



<form runat=“server”>



 <asp:DropDownList id=“Country” runat=“server”>









<asp:ListItem name=“USA” value=“0” />



<asp:ListItem name=“Canada” value=“1” />



<asp:ListItem name=“Mexico” value=“2” />









 </asp:DropDownList>



 <asp:Button runat=“server”



PostBackUrl=“Page2.aspx” />









</form>
















TABLE 3





An example page configured to be the target page of a


cross-page post.

















public void Page_Load(Object sender, EventArgs e) {









int selectedCountryCode = −1;



// Access a DropDownList control on the page we were









posted from









//



DropDownList country = (DropDownList)









PreviousPage.FindControl(“Country ”);









selectedCountryCode = country.SelectedItem.Value;









}
















TABLE 4





Another example page configured to be the target page of a


cross-page post.

















<%@ PreviousPage VirtualPath=“/default.aspx” %>



public void Page_Load(Object sender, EventArgs e) {









int selectedCountryCode = −1;



// Access a public property on the page posted from



//



selectedCountryCode =









PreviousPage.SelectedCountry.SelectedItem.Value;



}









Table 2 shows an example code for an original web page that includes a drop down list control configured for a cross-page post to another web page. Table 3 shows an example code for accessing an original web page where a post has been initiated. Accessing the “posted from” page may be accomplished using the PreviousPage property, which may return type System.Web.UI.Page. Table 4 shows a special “page” directive to control the type returned by the PreviousPage property.
FIG. 7 illustrates an example computing device 700 within which the described systems and methods can be either fully or partially implemented. Computing device 700 is only one example of a computing system and is not intended to suggest any limitation as to the scope of the use or functionality of the invention.
Computing device 700 can be implemented with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use include, but are not limited to, personal computers, server computers, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, gaming consoles, distributed computing environments that include any of the above systems or devices, and the like.
The components of computing device 700 can include, but are not limited to, processor 702 (e.g., any of microprocessors, controllers, and the like), system memory 704, input devices 706, output devices 708, and network devices 710.
Computing device 700 typically includes a variety of computer-readable media. Such media can be any available media that is accessible by computing device 700 and includes both volatile and non-volatile media, removable and non-removable media. System memory 704 includes computer-readable media in the form of volatile memory, such as random access memory (RAM), and/or non-volatile memory, such as read only memory (ROM). A basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within computing device 700, such as during start-up, is stored in system memory 704. System memory 704 typically contains data and/or program modules that are immediately accessible to and/or presently operated on by processor 702.
System memory 704 can also include other removable/non-removable, volatile/non-volatile computer storage media. By way of example, a hard disk drive may be included for reading from and writing to a non-removable, non-volatile magnetic media; a magnetic disk drive may be included for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”); and an optical disk drive may be included for reading from and/or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD, or any other type of optical media.
The disk drives and their associated computer-readable media provide non-volatile storage of computer-readable instructions, data structures, program modules, and other data for computing device 700. It is to be appreciated that other types of computer-readable media which can store data that is accessible by computing device 700, such as magnetic cassettes or other magnetic storage devices, flash memory cards, CD-ROM, digital versatile disks (DVD) or other optical storage, random access memories (RAM), read only memories (ROM), electrically erasable programmable read-only memory (EEPROM), and the like, can also be utilized to implement exemplary computing device 700. Any number of program modules can be stored in system memory 704, including by way of example, an operating system 720, application programs 728, and data 732.
Computing device 700 can include a variety of computer-readable media identified as communication media. Communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” refers to a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above are also included within the scope of computer-readable media.
A user can enter commands and information into computing device 700 via input devices 706 such as a keyboard and a pointing device (e.g., a “mouse”). Other input devices 706 may include a microphone, joystick, game pad, controller, satellite dish, serial port, scanner, touch screen, touch pads, key pads, and/or the like. Output devices 708 may include a CRT monitor, LCD screen, speakers, printers, and the like.
Computing device 700 may include network devices 710 for connecting to computer networks, such as local area network (LAN), wide area network (WAN), and the like.
Although the invention has been described in language specific to structural features and/or methodological steps, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or steps described. Rather, the specific features and steps are disclosed as preferred forms of implementing the claimed invention.

## Claims

1. A method of communication between a client and a server comprising:
receiving, by the server from the client, a request for a first web page;
determining, by the server, control objects associated with the first web page;
determining, by the server, initial viewstate data associated with the control objects, the initial viewstate data representing initial configurations of the control objects associated with the first web page;
computing, by the server, a first value based, in part, on the initial viewstate data, the first value uniquely identifying the initial viewstate data;
sending, by the server to the client, the first web page, the initial viewstate data, and the first value, the initial viewstate data stored at the client;
receiving, by the server from the client a post request for a second web page and revised viewstate data and user inputs, wherein the second web page is posted from the first web page, and wherein the revised viewstate data represents changed configurations of control objects, when the changed configurations of the control objects result from a user input associated with the first web page;
computing the first value from the revised viewstate data;
determining a second value within the revised viewstate data object;
upon determining that the first value and the second value match, creating, by the server, copies of the control objects associated with the first web page in accordance with the revised viewstate data received from the client;
generating, by the server, the second web page based, at least in part, on the copies of the control objects associated with the first web page created by the server, such that the object related data of the first web page does not need to be regenerated to generate the second web page;
sending, by the server to the client, the second web page and initial viewstate data associated with the second web page; and
deleting, prior to receiving any further revised viewstate data from the client, the copies of the control objects associated with the first web page in accordance with the revised viewstate data received from the client.

2. The method as recited in claim 1, further comprising:
serializing, by the server, the viewstate data; and sending, by the server to the client, the serialized data in accordance with hyper text transfer protocol (HTTP).

3. The method as recited in claim 1, further comprising encrypting, by the server, the viewstate data using a hashing function with the MAC as a key.

4. One or more computer-readable memories containing instructions that are executable by a processor to perform the method recited in claim 1.

5. A method comprising:
receiving, from a client, a request for posting to a second web page to the client, the request including a user input and a first set of object-related data stored at the client and associated with objects in a first web page displayed by the client, the first set of object-related data including information describing the current state of the objects in the first web page, thereby providing sufficient state information to allow a duplicate of the objects in the first web page to be instantiated by a computer remote from the client;
computing a first value from the first set of object-related data, the first value uniquely identifying the first set of object-related data;
determining a second value within the first set of object-related data;
upon determining that the first value and the second value match, generating at least one object in the second web page based on the instances of the objects in the first web page;
generating rendering data for the second web page based on the user input and the recreated instances of the objects on the computer remote from the client such that the object related data of the first web page does not need to be regenerated to generate the second web page.

6. The method as recited in claim 5, wherein the first web page includes at least one object representing a control and the first set of object-related data includes viewstate data representing a configuration of the control.

7. The method as recited in claim 6, wherein the configuration of the control includes at least one of a property, a state, or a behavior.

8. The method as recited in claim 6, wherein the control includes at least one of a checkbox, a textbox, a menu selector, a button, or a selectable area.

9. The method as recited in claim 5, wherein the first set of object-related data is deleted from the computer remote from the client when the at least one copy of the object is deleted.

10. The method as recited in claim 5, further comprising:
if the first value and the second value do not match, determining that there is an error in the first set of object-related data.

11. The method as recited in claim 10, wherein the first value is a message authentication code (MAC) associated with the first set of object-related data.

12. The method as recited in claim 11, wherein the first set of object-related data is encrypted with a hash function that includes the MAC as a key.

13. The method as recited in claim 5, further comprising:
determining a second set of object-related data representing configurations of objects in the second web page; and
sending the rendering data of the second web page and the second set of object-related data to the client.

14. The method as recited in claim 5, wherein generating the rendering data includes obtaining programmatic access to at least one copy of an object in the first web page.

15. The method as recited in claim 5, further comprising incorporating at least one copy of an object in the second web page.

16. The method as recited in claim 5, further comprising serializing the second set of object-related data.

17. The method as recited in claim 16, further comprising sending the serialized data to the client in accordance with hyper text transfer protocol (HTTP).

18. The method as recited in claim 17, wherein the serialized data is sent in an HTTP hidden field.

19. The method as recited in claim 1, further comprising:
determining whether a user associated with the client possesses permission to access the first web page; and if the user does not have the permission, returning an error message to the client.

20. An apparatus comprising:
a processor;
means for receiving and storing object-related data associated with a previous web page and a post to a requested web page from a client, the post including a user input and the object-related data, the object-related data including information about a state of the objects in the previous web page sufficient to allow copies of the objects in the previous web page to be instantiated;
means for computing a first value from the object-related data, the first value uniquely identifying the first set of object-related data;
means for determining a second value within the object-related data;
means for determining that the first value and the second value match;
means for creating copies of the objects associated with the previous web page based, at least in part, on the object-related data; and
means for generating rendering data of the requested web page based on the user input and, at least in part, on the reconstructed object instances, such that the object related data of the previous web page does not need to be regenerated to generate the requested web page.

21. The apparatus as recited in claim 20, further comprising:
means for determining that there is an error in the first set of object-related data if the first MAC and the second MAC do not match.

22. The apparatus as recited in claim 20, further comprising:
means for determining object-related data representing configurations of objects in the requested web page; and
means for sending the rendering data of the requested web page and the determined object-related data to the client.

23. The apparatus as recited in claim 20, further comprising:
means for determining whether a user associated with the client possesses permission to access the previous web page; and
means for returning an error message to the client if the user does not have the permission.

24. A system comprising:
a server configured to receive from a client a post request for a second web page including a user input and object-related data, stored at the client, that is associated with a first web page displayed on the client, the server further configured to compute a first value from a first set of object-related data, the first value uniquely identifying the first set of object-related data; the server further configured to determine a second value within the first set of object-related data and upon determining that the first value and the second value match, the server being further configured to instantiate copies of at least some of the objects associated with the first web page with configurations identified by the object-related data and to generate the second web page based on the user input and, at least in part, on the copies and further configured to send the second web page to the client in response to the post request, such that the object related data of the first web page does not need to be regenerated to generate the second web page and, after generating the second web page, deleting the copies of the objects associated with the first web page prior to receiving a response from the client.

25. A system comprising:
a client configured to receive and store initial object-related data associated with a first web page, the object-related data representing initial configurations of objects in the first web page, the object-related data further associated with a first value based, in part, on the object related data, the first value uniquely identifying the first set of object-related data, the client being further configured to post from the first web page to a second web page and to include a user input and a revised object-related data along with a post request for the second web page wherein the revised set of object-related data represents a current state of the objects in the first web page; and
a server configured to receive from the client the post request for the second web page and the revised object-related data, the server further configured to compute a first value from a first set of object-related data, the value uniquely identifying the first set of object-related data; the server further configured to determine a second value within the first set of object-related data and upon determining that the first value and the second value match, the server being further configured to instantiate copies of one or more of the objects associated with the first web page with the current state represented by the revised object-related data and to generate the second web page based on the user input and, at least in part, on the copies, such that the initial object related data of the first web page does not need to be regenerated to generate the second web page.

26. The system as recited in claim 25, wherein the object-related data are data representing configurations of at least one control object in the first web page.

27. The system as recited in claim 24, further comprising a data store having objects used by the server to generate web pages.

28. The system as recited in claim 27, wherein the objects in the data store are associated with dynamic content.

29. The system as recited in claim 28, wherein the dynamic content is stored in another server.