Patent Publication Number: US-7225225-B2

Title: Selective synchronization of web browsers

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not applicable. 
   BACKGROUND OF THE INVENTION 
   The present invention relates to World-Wide Web (web) browsers and, more particularly, to a system for selectively synchronizing the display and manipulation of web pages and other objects by a plurality of web browsers. 
   The World Wide Web (the “web”) is a system of Internet servers that supports hypertext and the hypermedia extension (collectively, “hypertext”). Hypertext is a database system that can be used to link software objects by including in an object a pointer to another object. Hypertext is used to link text, sounds, images, programs, and other software objects. The web is typically accessed with a web browser, a computer program that fetches and displays objects, including web documents or pages formatted with HTML (Hypertext Markup Language) or XML (eXtended Markup Language). Specially formatted text or icons (hyperlinks or links) in the web page are hypertext pointers to other objects. A user can cause the browser to display another object by selecting the appropriate link. In addition, a browser can display dynamic effects produced by manipulation of software objects (such as a change in text color) upon the occurrence of an event specified in the displayed page (for example, movement of a cursor). Web browsers also typically include search capabilities to facilitate locating web pages of interest to the user. While the web potentially links millions of individual users and millions of documents, historically the model of the web has been that of the individual user searching out and displaying documents of interest to that user. 
   Synchronization technology has been developed to facilitate collaborative use of the web by groups of users. Page and object synchronization permits a plurality of web browsers engaged in a synchronized session to simultaneously display the same web page and the results of an action manipulating a displayed object. Synchronized page display and interaction with objects are bases of web conferencing services and are potentially valuable tools for e-commerce. For example, a buyer and a seller can simultaneously view the same product specifications or other commercial documentation. 
   While page and object synchronization facilitates global display of web pages and other objects, there are circumstances where it is desirable that certain actions be limited to a subset of users in the session. For example, during an e-commerce session a sales agent may wish to refer to a proprietary price list without disclosing the document to the potential purchaser. However, if the price list is opened on the agent&#39;s page-synchronized browser it will be displayed on the synchronized display of the purchaser&#39;s browser. On the other hand, the agent may wish to open an explanatory document in a window or frame for viewing by the purchaser. However, page synchronization does not support the use of frames. If one member of a session selects a hyperlink to load a new page into a frame displayed by a first web browser, the page will not necessarily be loaded in the proper frame on the remaining browsers of the session. 
   Likewise, object synchronization permits one user to cause an action manipulating a displayed object to be replicated on the browsers of the other users in the synchronized session. For example, a script language can be used to specify the occurrence of an action (such as, a change in text color) upon the happening of an event (such as, a mouse click) associated with an object (a section of text). When a first web browser of the synchronized session detects the event, it signals the other browsers of the session to display the same action as if the local user has instigated the event. However, it may be desirable that the action be initiated or displayed on a limited set of browsers of the session. For example, the sales agent may wish to display a message on a customer&#39;s remote display in response to a mouse click on the agent&#39;s local display without displaying the message locally. 
   What is desired, therefore, is a system to control object and page synchronization permitting user inputs at selected browsers engaged in a synchronized session to manipulate and display pages and other objects on a subset of the browsers of the session. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic illustration of a synchronized web browsing session. 
       FIG. 2  is a block diagram of a web browser incorporating selective page synchronization. 
       FIG. 3  is an illustration of an exemplary display of frames by a web browser. 
       FIG. 4  is a tabulation of exemplary location attributes and corresponding functions for selective synchronization of web browser events. 
       FIG. 5  is a flow diagram of the selective synchronization method of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG.1 , a typical synchronized World Wide Web (“web”) session comprises a plurality of remote user data processing devices  10 ,  12 , and  14  connected to the Internet  16 , a network of interconnected servers and terminals. Typically, the user devices  10 ,  12 , and  14  are equipped with a web browser that permits the user to search for data files or web pages stored on the Internet and to retrieve and display selected pages. Synchronization technology permits all of the various browsers operating on the devices  10 ,  12 , and  14  of the synchronized session to simultaneously display the same web page and the same dynamic effects involving displayed software objects. 
   Referring to  FIG. 2 , the web browser  20  useful for selective synchronized browsing includes facilities to fetch and display web pages and to communicate with the other browsers of the synchronized session. The web browser  20  includes a communication manager  22  to execute communication protocols necessary to communicate over the network  16 . When a data file, in the form of a web page, is received from a web server (not illustrated) by the communication manager  22  a document parser  24  parses the elements of the file (e.g., tags, attributes, and scripts) and generates an intermediate form of the document. A layout engine  26  identifies objects comprising the page and determines the positions of the objects when displayed by a user interface  30 . Hypertext Markup Language (HTML) supports the division of the browser display area  50  into a plurality of independent windows or frames  52 ,  54 , and  56  each displaying a different web page as illustrated in  FIG. 3 . The multiple frames permit the web page designer to keep some information visible while other views are scrolled or replaced with new content. The frames of the display are defined by a frameset document that describes the dimensions, borders, initial content and other attributes of each of the frames comprising the display. 
   The layout engine  26  also determines if a displayed web page specifies an event in association with a displayed input object. An object comprises an item, including a page or a link, that can be selected and manipulated. An event is an action or occurrence that is generated by the browser  20  in response to an input producing an effect on an object. Events can be initiated by user actions, such as movement of the cursor or depression of a mouse button, or by an occurrence in the system, such as running out of memory. An association between an object and an event can be established with a script language, such as JavaScript; a browser plug in; a programming language, such as Java or Active X; or by a combination of these tools. For instance, JavaScript is a dynamic scripting language providing a list of events that can be associated with software objects by including a description of the event in the web document. For example, the JavaScript event attribute “onmouseover” can be used to initiate an action manipulating an object when the mouse pointer is moved to the location of the display specified in the attribute. The objects comprising the page and the events associated therewith are registered with an event manager  28 . The event manager  28  controls the objects and the associated events and causes the user interface  30  to display the objects of the web page. 
   While a web page is displayed, the user interface  28  monitors input to determine if the user has performed an action initiating an event. For example, a user can request an event with a key stroke, movement of a mouse pointer, or a mouse click. If user input is detected, the user interface  30  transfers the input to the layout engine  26  which typically identifies the appropriate input object from the position of the mouse pointer at the time of the input. The layout engine  26  notifies the event manager  28  of the event corresponding to the user input and related input object. If the event is registered with the event manager  28  for the associated input object, the browser generates the event and begins to load a new page or otherwise manipulate an object as required by the attributes of the event. For example, if the event is specified in a script language, the script engine  32  is directed to execute the specified action. 
   Synchronized operation of a plurality of browsers is facilitated by a synchronization manager  34 . Upon the occurrence of an event, such as loading a page, the layout engine  26  directs the synchronization manager  34  to send a synchronizing command to the other browsers of the session. The synchronization manager  34  formats a message identifying a URL (Uniform Resource Locator) for a page to be opened or noticing the occurrence of an event manipulating an object and identifying of the associated object. The synchronization manager  34  causes the communication manager  22  to broadcast the message to all other browsers participating in the session. The communication manager  22  of a browser receiving the notification, passes the message to the receiver&#39;s synchronization manager  34  which interprets the message and sends a command to the layout engine  26 . The receiver&#39;s layout engine  26  invokes the action specified in the message and begins downloading the page or directs the manipulation of the associated object on the local display. A second user, viewing a display identical to that viewed by the first user, sees an effect on an event instigated by input of the first user replicated on the second display. 
   While synchronized display of a web page by a plurality of browsers facilitates collaboration, the present inventors realized that synchronization of all content for all participants in a session may not be desirable. For example, discussions between a sales person and a potential customer may be facilitated by the simultaneous display of a product specification. On the other hand, the sales person may also wish to refer to a confidential price list without having the document disclosed to the customer. If the price list is retrieved and displayed by the sales person&#39;s browser, page synchronization will cause the document to be displayed to the customer. On the other hand, it may be desirable for the sales person to open an explanatory document in a frame displayed by the remote customer&#39;s browser. However, page synchronization does not support the use of frames and does not permit the contents of a frame on one display to be properly displayed by a second browser of the session. The present inventors concluded that synchronized browsing could be enhanced if the location of an input triggering an action and the location of corresponding action could be specified. The inventors concluded that selective synchronization of web browser displays could be achieved by including in the description of an event, a location attribute specifying at least one of a local or a remote browser as a source of an input instigating the event or the site at which the effect on the object is to be produced. 
   For example, a web page designer may desire that an input by a first user at a local browser cause an action to occur only at a remote browser even though the two browsers are displaying the same web page. The following exemplary HTML coding includes a location attribute identifying the browser that is to display the action in response to an event generated by the local user&#39;s input:
         &lt;HTML&gt;   &lt;HEAD&gt;   &lt;TITLE&gt;Test&lt;/TITLE&gt;   &lt;/HEAD&gt;   &lt;BODY BGCOLOR=“white”&gt;   &lt;LAYER ID=“text1” on_remote_mouseover=“bgColor=‘pink’”   on_remote_mouseout=“bgColor=‘white’”   Move the mouse pointer here   &lt;/LAYER&gt;   &lt;/BODY&gt;   &lt;/HTML&gt;
 
As indicated in the code, the background color (BGCOLOR) is to be changed to pink when the mouse pointer is moved to (mouseover) the text “Move the mouse pointer here.” The JavaScript attribute “onmouseover” has been modified by the location attribute “on_remote_” to specify that the action is to occur only on the remote browsers of the session. Likewise, when the mouse pointer of the local browser is moved off the text the background color on the remote browsers returns to white (on_remote_mouseout=“bgColor=‘white’”). Referring to  FIG. 4  location attributes “on_local_”  78  or “on_both_”  80  could be used to specify that the action is to occur only at the local browser or is to occur at both the local and remote browsers, respectively.
       

     FIG. 4  is a table listing exemplary location attributes  72  and corresponding function descriptions  74 . In addition, the table lists existing attributes  78 , such as the attributes “onmousedown” and “onmouseover” whose operation is modified by the location attribute  72 . For example, the location attribute “on_remote_”  82  can be used to modify one of the existing attributes, such as “onmouseover” to cause the effect to occur on a remote browser in response to the movement of the mouse pointer over the associated object. The location attribute “wcurser=‘originator’”  84  permits the web page designer to specify the location of the action that initiates the loading of a web page. For example, a lecturer could present a page for review on a group of browsers by selecting a hyperlink on the lecturer&#39;s browser with the location attribute “wcurser=teacher” if the lecturer&#39;s browser has the specified property “teacher.” When the attribute is detected the browser compares a property identifying the browser with the identity of the originator specified by the attribute. The location attributes “remote_target=‘frame_name’”  86  and “local_target=‘frame_name’”  88  permits a web page to specify either the remote or local browser and a target frame on the specified browser as the location of a web page to be loaded. For example, a sales person might desire to illustrate a point in a presentation by causing a page with product details to be opened in a frame on the customer&#39;s browser. The following code identifies the new page to be opened “details.html,” the location at which the page is to be loaded (frame one displayed by the remote browser), and the originator of the action (the browser having the property “agent”):
         &lt;A HREF=“details.html” remotetarget=“Frame1” wcurser=“agent”&gt;
 
The location attribute “wc=”  90  permits identification of browsers (local, remote, or both) loading a web page to specified in the hyperlink to the new page.
       
   Referring to  FIG. 5 , when the user interface  30  of the browser  20  of the present invention detects an input  100  related to a displayed or input object, the interface transfers the input to the layout engine  26  to generate an event  101  and identify the associated object and the frame in which the object is located  102 . The layout engine  26  notifies the event manager  28  of the input. The event manager  28  determines if action is required  104  by determining if the event is registered for the detected input object. If the event is not registered for the object, no action is required and the process ends  114 . If the event is registered for the object, the browser reads the location attribute  106  (for example, “on_remote_”) and determines whether action is required at the remote browsers of the session  108 . If action at the remote browsers of the session is required, the synchronization manager  34  is notified and a synchronization command is formatted and sent by the communication manager  22  to the remote browsers  109  to initiate the action. The synchronization manager  34  of a browser receiving the synchronization command directs the browser to download the required page or perform the required manipulation of the associated object. The local browser then determines if local action is specified by the location attribute for the event  110 . If local action is specified by the location attribute (such as “on_local_” or “on_both_”), the local browser downloads the appropriate page or performs the dynamic effect  112  before completion  114  of the process. If local action is not specified by the location attribute (such as, “on_remote_”) associated with the event, the process ends  114  without action by the local browser  112 . 
   Selective synchronization of a plurality of browsers engaged in a synchronized session permits more meaningful participation by the session members. There are many situations where some but not all members of the group wish to see information or where it is desirable to present information to a limited part of the group. The browser of the present invention permits web page designers to identify the originator and the recipients of synchronized web activities. 
   All the references cited herein are incorporated by reference. 
   The terms and expressions that have been employed in the foregoing specification are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims that follow.