Tier-neutral development mechanism for hypertext based applications

• US 6,049,664 A
• Filed: 11/25/1997
• Issued: 04/11/2000
• Est. Priority Date: 11/25/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: AlphaBlox Corp. (International Business Machines Corporation)
• Inventors: Swenson, Eric J., Skok, Michael J., Stave, Matthew, Dale, Geoffrey W., Poonen, Sanjay J.
• Primary Examiner(s): Hafiz, Tariq R.
• Assistant Examiner(s): Chavis, John Q.
• Application Number:
  US08/978,349
• Time in Patent Office: 868 Days
• Field of Search: 395/701, 395/682, 395/685
• US Class Current: 717/174
• CPC Class Codes: G06F 9/4862 the task being a mobile agent, i.e. specifically designed to migrate
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A tier-neutral development mechanism for network-based applications is provided. An application created using the mechanism includes a plurality of hypertext-based pages, at least some of which incorporate executable components. The application is invoked by a hypertext request for a page from a browser running on a client tier. An application server responds to the request by retrieving the requested page and assigning any components incorporated therein to the proper tier for execution. The mechanism provides a single model by which any executable component can be specified by an application developer for execution on any tier on the network or made subject to an automatic, dynamic tier assignment by the application server. Components of a given application can be distributed across, and specified for execution on, three or more different tiers and moved from tier to tier. An application developer can use a conventional hypertext editor to integrate selected components into extended hypertext pages to create an application.

Claims

1. A mechanism for enabling a developer to create a software application for execution on a network having a plurality of tiers, the mechanism comprising:

specifying means for enabling the developer to specify a plurality of executable components; and

means for enabling the executable components to be associated with at least one hypertext-based document, such that the executable components are executable in response to requests for the at least one hypertext-based document, and such that an executable component of the plurality of executable components can be automatically and dynamically assigned to an appropriate tier for execution at run-time in response to a request for an associated hypertext-based document or can be specified to execute on a particular tier using an applet tag specifying the tier within the associated hypertext-based document.

2. A mechanism according to claim 1, wherein the specifying means comprises means for specifying a plurality application components of a single software application for execution on at least three separate tiers of the network.

3. A mechanism according to claim 2, wherein the plurality of tiers includes at least one server tier and at least one client tier.

4. A mechanism according to claim 1, wherein each of the application components is an object.

5. A mechanism for enabling execution of a software application, the software application configured for execution on at least one tier of a network having a plurality of tiers, the software application including at least one hypertext-based page referencing at least one executable component, the mechanism comprising;

means for assigning a first executable component to a tier of the network based on an applet tag specifying the tier in one of said at least one hypertext pages;

means for receiving from a remote tier a request for one of the at least one hypertext-based pages referencing a second executable component;

means for dynamically and automatically determining at run time on which tier of the network the second executable component should be executed in response to the request without using information specifying a tier; and

means for causing the second executable component to be executed on an appropriate tier of the network in response to the request, based on a result of said determining.

6. A mechanism according to claim 5, further comprising means for providing the requested hypertext-based page to the remote tier in response to the request.

7. A mechanism according to claim 5, wherein the means for determining comprises means for determining on which tier of the network said component should be executed based on an attribute associated with said component.

8. A system for enabling a software application to be executed on at least one of a plurality of tiers on a network, the system comprising:

a processor;

a first storage unit accessible to the processor and having stored therein a plurality of executable components, and

a second storage unit accessible to the processor and having stored therein a plurality of pages functionally connected by hypertext links, the plurality of pages incorporating the plurality of executable components;

wherein the processor is configured to;

receive a request for one of the pages from a remote tier on the network; and

access one of the pages and a corresponding first one of the executable components in response to the request;

dynamically and automatically identify at run time an appropriate tier on which said first one of the executable components should be executed in response to the request without using information specifying a tier assignment; and

cause said first one of the executable components to be executed on said appropriate tier in response to the request, including causing the requested page to be provided to the remote tier after the first one of the executable components is executed if the remote tier is not identified as said appropriate tier.

9. A system according to claim 8, wherein the processor is configured to dynamically identify said appropriate tier at run time based on a current parameter.

10. A system according to claim 8, wherein the processor is further configured to:

determine whether the first one of the executable components should be executed on the remote tier; and

cause the first one of the executable components to be executed before the requested page is provided to the remote tier, if it is determined that the first one of the executable components should not be executed on the remote tier.

11. A system according to claim 8, wherein execution of said component results in an output, and wherein the processor is further configured to incorporate the output into the requested page before the requested page is provided to the remote tier if said first one of the executable components should not be executed on the remote tier.

12. A system according to claim 8, wherein the application further comprises at least one hypertext-based page referencing a second one of the executable components and at least one hypertext-based page referencing a third one of the executable components;

and wherein the processor is further configured to;

receive a request for a hypertext-based page referencing the second one of the executable components;

receive a request for a hypertext-based page referencing the third one of the executable components;

determine on which tier of the network each of the second and third ones of the executable components should be executed;

causing the second one of the executable components to be executed on a second tier of the network; and

causing the third one of the executable components to be executed on a third tier of the network.

13. An apparatus for executing a software application distributed across multiple tiers of a network having a plurality of tiers, the software application including a plurality of hypertext-based documents and a plurality of executable components referenced by the plurality of hypertext-based documents, the apparatus comprising:

means for receiving a request for one of the hypertext-based documents;

means for assigning each of the executable components to an appropriate tier in response to the request, including

means for assigning at least one of executable components to an appropriate tier based on an applet tag specifying a tier within a corresponding one of the hypertext-based documents; and

means for dynamically and automatically assigning at least one of the executable components to an appropriate tier at run time without using information specifying a tier assignment; and

means for establishing a functional connection between one of the executable components residing on a first tier and another one of the executable components residing on a second tier in response to a request generated by said one of the executable components, including means for establishing said functional connection without using a definition of the functional connection.

14. An apparatus according to claim 13, wherein the plurality of tiers includes at least one server tier and at least one client tier.

15. An apparatus according to claim 13, wherein the means for dynamically and automatically assigning comprises means for determining on which tier of the network said component should be executed at run time, based on a current parameter associated with the network.

16. A method of creating a software application for execution on a network having a plurality of tiers, the method comprising:

creating a plurality of executable components; and

associating each of the executable components with at least one hypertext-based document, such that each of the executable components can execute in response to a request for a corresponding hypertext-based document, wherein said associating includes assigning at least one of executable components to execute on a particular tier of the plurality of tiers by providing an applet tag in the corresponding hypertext-based document specifying the tier, and wherein at least one of the executable components can be automatically and dynamically assigned to an appropriate tier at run-time in response to a request for an associated hypertext-based document.

17. A method according to claim 16, wherein said specifying comprises specifying the executable components to execute on at least three different tiers of the network.

18. A method of executing an application on a network having a plurality of tiers, the application including at least one hypertext document and a plurality of executable components referenced by said at least one hypertext document, the plurality of executable components including a first executable component, a second executable component, a third executable component and a fourth executable component, the plurality of tiers including a first tier, a second tier, and a third tier, the method comprising the steps of:

receiving from a client system a request to execute the application, the request including at least one request for said at least one hypertext document;

in response to the request to execute the application, dynamically and automatically assigning each of the first, second, and third executable components to an appropriate tier of the network for execution at run time without using information specifying a tier; and

assigning the fourth executable component to an appropriate tier based on an applet tag of said at least one hypertext document specifying the tier.

19. A method according to claim 18, wherein said assigning comprises:

assigning the first executable component to be executed on the first tier;

assigning the second executable component to be executed on the second tier; and

assigning the third executable component to be executed on the third tier.

20. A method according to claim 18, wherein the first tier is the client system, the second tier is a first server system, and the third tier is a second system.

21. A method according to claim 18, wherein each of the first, second, and third executable components is an object.

22. A method according to claim 18, wherein the assigning step comprises, for at least one of the first, second, and third executable components, dynamically determining on which tier of the network the component should be executed at run time based on a current state.

23. A method according to claim 18, wherein each application component is defined according to a single mechanism by which an application component can be specified for execution on any tier on the network.

24. A method of executing a software application, the software application configured for execution on at least one tier of a network having a plurality of tiers, the software application including at least one hypertext-based page referencing at least one executable component, the method comprising the steps of:

receiving from a remote tier a request for a first hypertext-based page referencing a first executable component of the software application;

determining on which tier of the network the first executable component should be executed based on an applet tag of the first hypertext-based page specifying a tier;

causing the first executable component to be executed on the specified tier;

receiving from a remote tier a request for a second hypertext-based page referencing a second executable component of the software application;

automatically and dynamically determining on which tier of the network the second executable component should be executed at run time without using information specifying a tier;

causing the second executable component to be executed on an appropriate tier of the network in response to the request; and

providing at least one of the first hypertext-based page and the second hypertext page to the remote tier.

25. A method according to claim 24, wherein said automatically and dynamically determining step comprises determining, in response to the request, on which tier of the network said component should be executed, based on a current parameter associated with the network.

26. A method according to claim 24, wherein each application component is defined according to a single mechanism by which an application component can be specified for execution on any of the plurality of tiers of the network.

27. A method according to claim 24, wherein step of causing the first executable component to be executed on an appropriate tier comprises the steps of:

determining whether the first executable component should be executed on the remote tier; and

causing the first executable component to be executed before providing said first hypertext-based page to the remote tier if the first executable component should not be executed on the remote tier.

28. A method according to claim 24, further comprising the step of, if the first component should not be executed on the remote tier, causing a result of executing the first component to be incorporated into the first hypertext-based page before providing the first hypertext-based page to the remote tier.

29. A method of executing a software application distributed across multiple tiers of a network having a plurality of tiers, the software application including a plurality of hypertext-based documents and a corresponding plurality of executable components referenced by the hypertext-based documents, the method comprising the steps of:

receiving a request for invoking the application by accessing at least one of the hypertext-based documents;

in response to the request, assigning each of the executable components to an appropriate tier, including

dynamically and automatically assigning at least one of the executable components to an appropriate tier at run time without using information specifying a tier assignment; and

assigning at least one of the executable components to an appropriate tier according to an applet tag specifying a tier in a corresponding hypertext-based document.

30. A method according to claim 29, wherein the assigning step comprises assigning said component to an appropriate tier of the network for execution based on a current parameter associated with the network.