Methods and Apparatus for Constructing Declarative Componentized Applications

• US 20090254584A1
• Filed: 06/17/2009
• Published: 10/08/2009
• Est. Priority Date: 01/26/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Leff, Avraham, Rayfield, James Thomas
• Granted Patent: US 8,250,112 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 8/38 for implementing user interfaces

Abstract

Techniques for constructing a software application are provided. A data model of the application is represented as a relational model. Control logic of the application is defined to specify each of a plurality of operations of the application as a mapping from a current state of the application data model and one or more current application inputs to a new state of the application data model and one or more application outputs, described by one or more relational algebra operations selected from the group consisting of a relation-complement operation, a disjunction operation and a conjunction operation.

Claims

1. A method of constructing a software application comprising the steps of:

representing a data model of the application as a relational model; and

defining control logic of the application to specify each of a plurality of operations of the application as a mapping from a current state of the application data model and one or more current application inputs to a new state of the application data model and one or more application outputs, described by one or more relational algebra operations selected from the group consisting of a relation-complement operation, a disjunction operation and a conjunction operation;

wherein each of the steps is performed at least in part by a computer.

2. The method of claim 1, wherein the data model comprises a relational database comprising a plurality of entries, each entry representing a mapping from a specified name to a specified value;

and wherein the operations of the application comprise a create operation, a delete operation, an update operation, and a delete operation.

3. The method of claim 2, wherein:

the create operation comprises performing the conjunction operation on the specified name and the specified value to generate a specified entry; and

performing the disjunction operation on the specified entry and the data model;

the retrieve operation comprises performing the conjunction operation on the specified name and the data model;

the update operation comprises performing the relation-complement operation on the specified name, performing the conjunction operation on an output of the relation-complement operation and the data model, performing the conjunction operation on the specified name and the specified value to generate the specified entry, and performing the disjunction operation on the specified entry and an output of the conjunction operation on the output of the relation-complement operation and the data model; and

the delete operation comprises performing the relation-complement operation on the specified name, and performing the conjunction operation on an output of the relation-complement operation and the data model.

4. The method of claim 1, further comprising the step of representing a user-interface of the application as a declarative view component model.

5. The method of claim 4, wherein, in the step of representing a user-interface, the user-interface comprises text entry fields.

6. The method of claim 4, wherein, in the step of representing a user-interface, the user-interface enables user interaction to facilitate a change from the current state of the application data model to a new state of the application data model.

7. The method of claim 6, wherein the change from the current state to the new state of the application data model comprises the steps of:

evaluating one or more inputs to the data model;

updating the state of the data model in accordance with the one or more inputs; and

updating the user-interface in accordance with the state of the data model.

8. The method of claim 7, wherein, in the step of evaluating one or more inputs, the evaluation is recursive until a state of the data model or of the user interface is defined.

9. The method of claim 2, wherein, in the step of representing a user-interface, the user-interface components have at least one of relational outputs and relational inputs.

10. The method of claim 1, wherein, in the step of defining control logic, the mapping described by relational algebra comprises an interconnection of encapsulated components.

11. The method of claim 1, wherein, in the step of defining control logic, the mapping described by relational algebra comprises a directed-acyclic graph of components.

12. The method of claim 1, wherein the software application comprises a user-interactive software application.

13. Apparatus for constructing a software application, comprising:

a memory; and

at least one processor coupled to the memory and operative to;

represent a data model of the application as a relational model; and

define control logic of the application to specify each of a plurality of operations of the application as a mapping from a current state of the application data model and one or more current application inputs to a new state of the application data model and one or more application outputs, described by one or more relational algebra operations selected from the group consisting of a relation-complement operation, a disjunction operation and a conjunction operation.

14. The apparatus of claim 13, wherein the data model comprises a relational database comprising a plurality of entries, each entry representing a mapping from a specified name to a specified value;

and wherein the operations of the application comprise a create operation, a delete operation, an update operation, and a delete operation.

15. The apparatus of claim 14, wherein:

the create operation comprises performing the conjunction operation on the specified name and the specified value to generate a specified entry, and performing the disjunction operation on the specified entry and the data model;

the retrieve operation comprises performing the conjunction operation on the specified name and the data model;

the update operation comprises performing the relation-complement operation on the specified name, performing the conjunction operation on an output of the relation-complement operation and the data model, performing the conjunction operation on the specified name and the specified value to generate the specified entry, and performing the disjunction operation on the specified entry and an output of the conjunction operation on the output of the relation-complement operation and the data model;

the delete operation comprises performing the relation-complement operation on the specified name, and performing the conjunction operation on an output of the relation-complement operation and the data model.

16. The apparatus of claim 13, wherein the processor is further operative to represent a user-interface of the application as a declarative view component model.

17. The apparatus of claim 13, wherein, in the operation of representing a user-interface, the user-interface enables user interaction to facilitate a change from the current state of the application data model to a new state of the application data model.

18. The apparatus of claim 17, wherein the change from the current state to the new state of the application data model comprises the steps of:

evaluating one or more inputs to the data model;

updating the state of the data model in accordance with the one or more inputs; and

updating the user-interface in accordance with the state of the data model.

19. The apparatus of claim 16, wherein, in the operation of representing a user-interface, the user-interface components have at least one of relational outputs and relational inputs.

20. An article of manufacture for constructing a software application, comprising a computer readable storage medium containing one or more programs which when executed implement the steps of:

representing a data model of the application as a relational model; and

defining control logic of the application to specify each of a plurality of operations of the application as a mapping from a current state of the application data model and one or more current application inputs to a new state of the application data model and one or more application outputs, described by one or more relational algebra operations selected from the group consisting of a relation-complement operation, a disjunction operation and a conjunction operation.