Abstract:
A portlet state maintenance system can include a portal page setup component configured to generate a logical form in a single portal page from a multiplicity of forms defined within portlet markup aggregated into the single portal page. A portal state save component further can be configured to save state values for selected portlets defined within the logical form. Finally, a portal state restore component can be configured to restore the saved state values in refreshed portlet markup for the selected portlets. Notably, a refresh timing component further can be configured to embed submit auto-initiation logic in the single portal page responsive to identifying a dynamic refresh requirement associated with the portlet markup in the single portal page. Finally, a portlet markup cache can be coupled to the portal state restore component.

Description:
BACKGROUND OF THE INVENTION 
   1. Statement of the Technical Field 
   The present invention relates to the field of portals and portlets and more particularly to the maintenance of screen and form state in portlets. 
   2. Description of the Related Art 
   Distributing content about large computer communications networks is not without its challenges. In particular, the quantity of content available for distribution in a computer communications network often varies proportionally to the size of the computer communications network. At the extreme, the Internet hosts a vast quantity of content not easily accessible by most end-users. Portals represent a sensible solution to the problem of aggregating content through a channel paradigm in a single, network-addressable location. In consequence, portals have become the rage in content distribution. 
   Portlets are the visible active components included as part of portal pages. Similar to the graphical windows paradigm of windowing operating systems, each portlet in a portal occupies a portion of the portal page through which the portlet can display associated content from a portlet channel. Portlets are known to include both simple applications such as an electronic mail client, and also more complex applications such as forecasting output from a customer relationship management system. The prototypical portlet can be implemented as server-side scripts executed through a portal server. 
   From the end-user perspective, a portlet is a content channel or application to which the end-user can subscribe. By comparison, from the perspective of the content provider, a portlet is a means through which content can be distributed in a personalized manner to a subscribing end-user. Finally, from the point of view of the portal, a portlet merely is a component which can be rendered within the portal page. In any case, by providing one or more individually selectable and configurable portlets in a portal, portal providers can distribute content and applications through a unified interface in a personalized manner according to the preferences of the end-user. 
   Portal servers are computer programs which facilitate the distribution of portal based Web sites on the public Internet or a private intranet. Importantly, it will be recognized by one of ordinary skill in the art that the signature characteristic of all conventional portal servers can include the aggregation of content from several portlet applications within a single distributable page in a uniform manner. To that end, each portlet application within the portal page can be represented by a portlet user interface distributed by the portal server to requesting client computing devices. 
   For the interactive portlet applications, a two-way portlet user interface can be provided. In the two-way user interface of the portlet application, user input can be forwarded to the portal server through the use of a submit action in which the user input can be posted or otherwise provided to the portal server. Subsequently, the portal server can forward the user input to the appropriate portlet application in which the user input can be processed by the application portlet. In this way, the portal can be viewed as a logical extension to the Web application in which the Web application has been formalized in terms of user and application interface. Some have postulated that the portal merely represents the next generation of the Web application. 
   With the enhanced functionality of the portal comes a price of complexity in managing multiple application states, both in the portal, and at the client computing device. This complexity has led to a limitation given current content browsing technology for use in the conventional client computing device. More particularly, when a user initiates a submit action in connection with a portlet user interface in the portal page, the input data in the portlet user interface can be returned to the portlet application running in the portal server. Yet, where data had been provided within multiple portlet user interfaces in the portal page, all but the data provided in the portlet user interface associated with the running portlet application will be lost. 
   Notably, some portlets periodically auto-initiate a submit event at regular intervals to trigger the portal server&#39;s refreshing of the latest state of the portlet application. The periodic auto-initiation of a submit event in a portlet user interface can magnify the problem of lost portlet data because at the time of submit, the portlet requesting the refresh may not necessarily have focus in the portal page. Moreover, the auto-initiation of a submit event in one portlet user interface may arise concurrently with the manual initiation of a submit event in another portlet user interface in the portal page. As the conventional content browser only can post the form data associated with the first occurring submit, the subsequent manually initiated submit will fail to forward the data portlet user interface data to the portal server for processing. 
   SUMMARY OF THE INVENTION 
   The present invention is a system, method and apparatus for maintaining the form and application state of a portlet application and corresponding portlet user interface. In accordance with the inventive arrangements, in association with one or more submit requests received from one or more corresponding portlets disposed in a portal page, the state for each other portlet in the portal page can be stored while the corresponding portlets can be refreshed by associated portlet applications. Once the corresponding portlets have been refreshed, the resulting data can be applied to the portal page as can the stored state for each other portlet in the portal page. In this way, the state of every portlet in the portal page can be maintained without risk of loss of data, regardless of the focus of the portal page. 
   A portlet state maintenance system can include a portal page setup component configured to generate a logical form in a single portal page from a multiplicity of forms defined within portlet markup aggregated into the single portal page. A portal state save component further can be configured to save state values for selected portlets defined within the logical form. Finally, a portal state restore component can be configured to restore the saved state values in refreshed portlet markup for the selected portlets. Notably, a refresh timing component further can be configured to embed submit auto-initiation logic in the single portal page responsive to identifying a dynamic refresh requirement associated with the portlet markup in the single portal page. Finally, a portlet markup cache can be coupled to the portal state restore component. 
   A portlet state maintenance method can include the step of receiving a submit request specifying a set of form field data in a portal page comprising a multiplicity of portlets aggregated within the portal page. A specific portlet in the portal page can be identified as a source of the submit request and a submit request and portions of the form field data associated with the specific portlet can be forwarded to a portlet application corresponding to the specific portlet. Others of the form field data can be associated with respective ones of the portlets and subsequently stored. Each portlet application corresponding to the respective ones of the portlets can be refreshed to produce refreshed portal markup, and form fields in the refreshed portal markup can be populated with the stored form field data. Finally, the refreshed portal markup and portal markup produced by the forwarded submit request can be aggregated in a new portal page which can be forwarded in response to the received submit request. 
   In a preferred aspect of the invention, the aggregating step can include the steps of stripping tags from the refreshed and produced portal markup which denote individual forms in each of the portlets, and adding a single set of form tags to the new portal page to denote a single, logical form. In this regard, the stripping step can include the step of converting each &lt;FORM&gt; tag in the refreshed and produced portal markup to a comment tag. The aggregating step also can include the steps of identifying specific portal applications requiring a dynamic refresh and determining a refresh interval for each of the identified specific portal applications. Each determined refresh interval can be compared to compute an earliest required refresh time. Finally, a script can be embedded in the portal page to trigger an auto-initiated submit request at the computed earliest required refresh time. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There are shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein: 
       FIG. 1  is a schematic illustration of a portal server system which has been configured to maintain the state of every portlet in a portal page which has been distributed to a content browsing client; 
       FIG. 2  is a block illustration of a system for maintaining state in a portal page; 
       FIG. 3  is a flow chart illustrating a process for maintaining state in a portal page; and, 
       FIG. 4  is a schematic illustration of a portal server system which has been configured to manage auto-initiated refresh requests in a portal page. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention is a system, method and apparatus for maintaining the state of a portal page responsive to one or more refresh requests initiated in portlets in the portal page in requesting client content browser. More particularly, in response to the issuance of one or more submit action in one or more corresponding portlets in the portal page, the state of every other portlet in the portal page can be identified and stored in the portal server pending the processing of the submit actions. Once the submit actions have been processed by the respective portlet applications, the resulting state can be combined with the stored state to produce a newly aggregated portal page which can be re-distributed to the requesting client content browser. 
     FIG. 1  is a schematic illustration of a portal server system which has been configured to maintain the state of every portlet in a portal page which has been distributed to a content browsing client. The portal server system can include a portal page  135  communicatively coupled to a selection of portlet applications  115 A,  115 B,  115   n  through a portal server  130 . Each portlet application  115 A,  115 B,  115   n  can produce a view based upon portlet data  120 A,  120 B,  120   n  in the form of portlet markup  125  through corresponding rendering logic  110 A,  110 B,  110   n . Notably, the rendering logic  110 A,  110 B,  110   n  can be active markup such as a JSP, in which logical scriptlets can be embedded to produce specific markup language tags. 
   A portlet aggregator  105  can be coupled to each portlet application  115 A,  115 B,  15   n  to receive the portlet markup  125  and to aggregate the portlet markup  125  into view in the portal page  135 . By aggregation, it is meant that the individual markup language blocks produced by each portlet  115 A,  115 B,  115   n  can be combined into a single cohesive markup language document configured for distribution to and use within a conventional content browser. In this regard, the portal page  135  can be disposed in the portal server  130  from which the portal  135  can be accessed by client content browsing devices  140  over a computer communications network  160  such as a local computer communications network, for instance a private intranet, or a global computer communications network, for instance the public Internet. 
   Importantly, a portal filter  145  can be coupled to the portal aggregator  105 . The portal filter  145  can intercept requests to and responses from the aggregator  105 . Through this interception mechanism, the portal filter  145  can process logic responsive to the intercepted requests or intercepted responses. In accordance with the inventive arrangements, the portal filter  145  can be configured to process state maintenance logic  150  in response to the interception of a submit request. The state maintenance logic  150  can store the state of each portlet in a portal page  135  which has not initiated the submit requests. 
   Conversely, the state maintenance logic  150  can request a refreshing of the portlet applications  15 A,  115 B,  115   n  associated with those portlets responsible for the submit request. Once the portlet applications  115 A,  115 B,  115   n  have produced refreshed portlet markup  125  in response to the refreshing requested by the state maintenance logic  150 , the refreshed portlet markup  125  can be combined with the stored states of each other portlet in the portal page  135  which had not initiated the submit requests. Subsequently, the combined portal page  135  can be returned to the client content browsing device  140 . 
   Notably, to ensure that each portlet in the portal page  135  can provide its state to the state maintenance logic  150  in response to a submit request, even where the submit request had been initiated in other portlets in the portal page  135 , each form component of each portlet in the portal page  135  can be combined into a single portal form. In this regard, the state maintenance logic  150  can strip the form tags of the portlet markup while wrapping the aggregated portal page in a single form tag. In this way, each form of each portlet in the portal page  135  will be viewed as just another element of a single form in the portal page  135 . Consequently, any submit request initiated in any portlet in the portal page  135  will cause the name value pairs of the entire form to be forwarded to the portal server  130 . 
   It will be recognized by the skilled artisan that by coupling the state maintenance logic  150  to the aggregator  105  through a portal filter, the state maintenance logic  150  can be applied to any portal server  130 , regardless of the source and configuration of the portal server  130 . Specifically, it is well known that portal filters generally implement a set of interfaces that allow the portal filter to be connected in the request and response call sequence to each portlet. Still, the invention is not so limited strictly to a portal filter implementation. Rather, the state maintenance logic  150  can be more closely linked to the portal server. For example, in an alternative aspect of the invention the state maintenance logic  150  can be incorporate into the portal server  130  itself. 
     FIG. 2  is a block illustration of a system for maintaining state in a portal page. As it will be apparent to the skilled artisan, the system of the present invention can include four components: a portal page setup component  210 , a portlet state save component  240 , a portlet state restore component  230 , and a portlet refresh timing component  220 . Each of the foregoing components can be coupled to a portal server through a portal filter  145 , though the invention is not so limited to a portal filter configuration as had been previously noted. 
   In accordance with the present invention, it is preferred that when a portlet within a portal page generates a submit event, all portlets within the portal page submit their respective form contents to the portal server. To ensure that such is the case, the portal page setup component  210  can combine the form markup of each portlet within the portal page into a single, logical form in the portal page. In order to seam lessly undertake the combination of all portlet forms into a single portal form, the &lt;FORM&gt; tags of each portlet form can be stripped therefrom, for instance by converting each &lt;FORM&gt; tag into a comment tag. In this respect, the tag &lt;FORM action=“save”&gt; can be converted to &lt;!-FORM action=“save”--&gt;, while the tag &lt;/FORM&gt; can be converted to &lt;!-/FORM-&gt;. 
   As it will be recognized by the skilled artisan, to perform the aforementioned conversion, the state maintenance logic must scan the aggregation stream to identify each &lt;FORM&gt; tag. To avoid the overhead of a scanning process as such, each the portlet rendering logic can avoid the use of hard-coded &lt;FORM&gt; tags with the use of script tags such as the JSP tags: &lt;wps:form action=“save”/&gt;, and &lt;wps:endform/&gt;. The script tags, in turn, can cause the generation of commented FORM tags. In any case, once the &lt;FORM&gt; tags have been stripped from the portlet markup, the aggregation stream can be wrapped with a single &lt;FORM&gt; tag at each end of the aggregation stream. Accordingly, a single, logical form can result. 
   In response to the receipt of one or more submit events generated in one or more respective portlets in a portal page, the portlet state save component  240  can save the state of each portlet in the portlet page which had not generated a submit event. More particularly, when a composite submit request is received from the client content browser, the portlet state save component  240  can save the value of any fields in any forms for all portlets except for the portlets which had generated the submit events. As the field values will be associated with specific fields in a single, virtual form, the portlet state save component can identify the portlet associated with any one field in the virtual form by way of a conventional namespace processing mechanism included with typical portal server systems. For those portlets which had generated the submit events, the portlet state save component  240  can deliver the submit event to each of such corresponding portlet applications where the events can be individually processed. 
   Once the submit event has been delivered to each of the portlet applications, the portlet applications can produce an updated state and respective portlet markup in response. The portlet markup can be returned to the aggregator where a now portal page can be constructed for transmission to the client content browser. To that end, each of the other portlet applications can be asked to refresh their respective portlet markup. As the aggregator receives the aggregation stream, the portlet state restore component  230  can restore the saved values into their respective portlets in the portal page. The resulting composite portal page can be returned to the client content browser, having included therein both the refreshed data and the restored data within a single virtual form. 
   Notably, though as part of the portlet aggregation process each of the portlet applications which had not processed a submit request still can be requested to refresh their respective views, it will be recognized by the skilled artisan that the refresh process can produce undesirable latencies in the responsiveness of the end to end submit process. These latencies will appear to the end user as a delay in processing the submit request or requests. Consequently, in a preferred aspect of the invention, a cache (not shown) can be coupled to the portlet state restore component  230  so that, where the caching rules permit, the entire portlet view can be restored from the cache without requiring a time consuming refresh call to the portlet application. 
   In furtherance of explaining the setup, save and restore aspects of the present invention,  FIG. 3  is a flow chart illustrating a preferred process for maintaining state in a portal page. Beginning in block  305 , portlet markup can be received in an aggregation stream. In block  310 , the tags within the portlet markup which denote the presence of a form can be neutralized, for instance by way of converting the tags to a comment tag. In block  315 , the portlet markup can be aggregated into a portal page having a single logical form. If in decision block  320  additional portlet markup remains to be processed, the receiving, neutralizing and aggregating steps can be repeated for the additional portlet markup. Otherwise, the process can continue through block  330  in which the portal page is forwarded to a requesting client content browser. 
   In decision block  335 , it can be determined whether one or more submit events have been received from the portal page. If so, in block  340 , the submit event or events can result in the receipt in the portal server of name value pairs or other request payload from the client content browser. In block  345 , a first form field in the request can be identified as can the namespace for the first form field. In decision block  350 , it can be determined whether the portlet associated with the namespace had generated any of the received submit events. If so, in block  360  the name value pair for the field can be forwarded to a corresponding portlet application along with a submit event. In this way, the portlet application can process the submit request as if the request had been directly exclusively at the portlet application. 
   If, however, in block  350  it is determined that the portlet associated with the namespace had not generated any of the received submit events, in block  355  the name value pair for the form field can be stored. Subsequently, in decision block  365  it can be determined if more fields remain to be analyzed in the request. Where additional fields in the request are to analyzed, in block  385  a next form field can be selected and the name space identified. The process can repeat, then, through blocks  350  through  365  as in the previous case. 
   Where no more form fields remain to be analyzed as determined in block  365 , in block  370  each portlet application having an associated stored state can be requested to refresh itself. In response, the portlet application can produce a refreshed view in the form of portlet markup. Once the refreshed portlet markup is received from each portlet application which can result from both the refresh and submit requests forwarded to the respective portlet applications, in block  375  the stored values can be retrieved for each portlet and in block  380  the refreshed portlet markup can be populated with the stored values and the process of blocks  305  through block  330  can produce and forward the resulting portal page. 
   Returning now to  FIG. 2 , it will be apparent that a refresh timing component  220  also can be included in the system of the present invention. The timing component  220  of  FIG. 2  can support auto-initiated refresh requests in portlet portions of the portal page. Specifically,  FIG. 4  is a schematic illustration of a portal server system which has been configured to manage auto-initiated refresh requests in a portal page  480 . To support auto-initiated refresh requests, each portlet application  410 A,  410 B,  410   n  can specify a refresh interval  490 A,  490 B,  490   n . The refresh interval  490 A,  490 B,  490   n  can be expressed, for instance, through a portlet descriptor, or through an application programming interface for the portlet application  410 A,  410 B,  410   n.    
   A refresh manager  420  can be coupled to the portal aggregator (not shown) of the portal server  440 . The refresh manager  420 , at the time of aggregation, can identify whether any portlet  470 A,  470 B,  470   n  of the portal page  480  requires dynamic refresh. Based upon all refresh intervals  490 A,  490 B,  490   n  for all portlets  470 A,  470 B,  470   n  in the portal page  480 , an earliest required refresh time  490  can be computed. Subsequently, the refresh manager  420  can add a script to the portal page  480 . The script can execute a loop which periodically determines whether the specified refresh time  490  has elapsed. If so, the script can auto-initiate a submit request from within the browser client  460  to the portal server  440  over the network  450 . 
   Upon receipt of the submit request, it can be determined which of the portlet applications  410 A,  410 B,  410   n  require a refresh resulting in a back-end refresh request to such portlet applications  410 A,  410 B,  410   n . It will be recognized by the skilled artisan that multiple, repetitive auto-initiated refresh events can cause undesirable latencies in the performance of the portal page  480 . Consequently, a fuzzy factor  430  can be applied to the refresh manager  420 . Whenever a submit request is received in the refresh manager  420 , notwithstanding the association of the submit request with a particular one of the portlets  410 A,  410 B,  410   n , the other portlets  410 A,  410 B,  410   n  can be inspected to determine whether their respective refresh intervals fall within the fuzzy factor  430 . If so, those other portal applications  410 A,  410 B,  410   n  determined to all within the fuzzy factor  430  also can be refreshed so as to not require additional refresh cycles. Accordingly, all proximately scheduled refresh events can be processed concurrently in a single refresh cycle. 
   The present invention can be realized in hardware, software, or a combination of hardware and software. An implementation of the present invention can be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein. 
   A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computer system is able to carry out these methods. 
   Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form. Significantly, this invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be had to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.