Creating and configuring component-based applications using a text-based descriptive attribute grammar

• US 6,083,276 A
• Filed: 06/11/1998
• Issued: 07/04/2000
• Est. Priority Date: 06/11/1998
• Status: Expired due to Term

• Current Assignee: Corel Corporation (Corel Holdings LP)
• Original Assignee: Corel Incorporated (Corel Holdings LP)
• Inventors: Davidson, Harold R., Penn, Derek
• Primary Examiner(s): Stamber, Eric W.
• Assistant Examiner(s): BOOKER, KELVIN
• Application Number:
  US09/096,848
• Time in Patent Office: 754 Days
• Field of Search: 395/701
• US Class Current: 717/107
• CPC Class Codes: G06F 8/30 Creation or generation of source code
• CPC Class Codes: G06F 8/427 Parsing
• CPC Class Codes: G06F 8/71 Version control security arrangements therefor G06F21/57; Configuration management

Abstract

A method for creating and configuring a component-based application through text-based descriptive attribute grammar includes creating a parse tree from an application description file, transforming the parse tree into a plurality of components corresponding to instances of classes in an application framework, and initializing and further processing the components to launch the component-based application. Additionally, a system for creating and configuring a component-based application includes a parser, a plurality of element processors, an element mapper, an attribute mapper, and a parameter converter.

Claims

1. A computer-implemented method for creating and configuring a component-based application, the method comprising the steps of:

receiving an application description file containing a definition of a component-based application;

generating, in a memory, a representation of a parse tree based on the application description file, the parse tree comprising at least one leaf;

for each of a first subset of the leaves,

mapping the leaf to a target class; and

instantiating a component associated with the target class; and

for at least a subset of the instantiated components, invoking at least one method of the component to launch the application.

2. The method of claim 1, wherein the step of generating a representation of a parse tree comprises parsing the application description file.

3. The method of claim 1, wherein the application description filed is a text-based, extensible markup language (XML) compliant document, and the parse tree is created by an XML parser.

4. The method of claim 1, wherein the at least one leaf comprises a data object from the group of data objects consisting of comments, processing instructions, elements, and raw data.

5. The method of claim 1, wherein the component is an instance of a class in an application framework.

6. The method of claim 1, wherein at least one leaf comprises an element including an attribute list comprising at least one attribute, the method further comprising the step of:

mapping at least one attribute in the attribute list of at least one leaf to a property of the component associated with the target class to which the leaf is mapped.

7. The method of claim 1, wherein the components comprise at least one parent component and at least one child component, and wherein the step instantiating a component comprises instantiating at least one child component before instantiating at least one parent component using a post-order recursive traversal of the parse tree.

8. The method of claim 1, wherein each leaf comprises a tag, and the step of mapping the leaf to a target class comprises the steps of:

comparing the tag of the leaf with a plurality of target class names in an application framework; and

selecting a target class with a matching name.

9. The method of claim 1, wherein the instantiating step comprises the steps of:

creating an element processor for the element, the element processor being associated with the target class; and

creating an uninitialized instance of the target class.

10. The method of claim 6, wherein each attribute comprises a name, and the step of mapping the at least one attribute to a property of the component comprises the steps of:

for each attribute in the attribute list,

searching an element mapper for a property descriptor having a name that matches the name of the attribute;

responsive to a match being found, obtaining a write method for the component property from the matching property descriptor; and

executing the write method to write the attribute to the component property.

11. The method of claim 10, wherein the write method comprises a parameter associated with the attribute, and the executing step comprises the steps of:

determining whether the parameter is of a same type as the attribute;

responsive to the parameter being a different type,

converting the type of the attribute to the type of the parameter; and

executing the write method with the attribute as the parameter.

12. The method of claim 1, further comprising the steps of:

for each component,

initializing the component; and

responsive to the component having a parent component, adding the component to the parent component.

13. A system for creating and configuring a component-based application, the system comprising:

at least one element processor for reading a parse tree comprising at least one element, and for at least a subset of the elements of the parse tree, transforming the element into a component in an application framework, and for transforming the component into a running application;

an element mapper, coupled to the at least one element processor, for mapping the element to a target class; and

an attribute mapper, coupled to the at least one element processor, for mapping an attribute of the element to a property of the component;

wherein the element processor transforms the element into the component by calling the element mapper to map the element, and instantiating the component.

14. The system of claim 13, wherein the element comprises:

a tag for identifying the element; and

an attribute list comprises a number of attributes corresponding to component properties.

15. The system of claim 13, wherein each attribute and property comprise a type, and the system further comprises:

a parameter converter, coupled to the attribute mapper, for converting the type of the attribute to the type of the component property.

16. The system of claim 13, further comprising

a parser, coupled to the at least one element processor, for creating a parse tree from an application description file comprising a text-based attribute grammar.

17. The system of claim 16, wherein the application description file is an XML-compliant, text-based document, and the parser is an XML parser.

18. The system of claim 13, wherein the attribute mapper comprises a plurality of property descriptors, each property descriptor comprising a name and a write method for writing an attribute to component property.

19. A computer-readable medium having computer-readable program code devices embodied therein for creating and configuring a component-based application, the computer-readable medium comprising:

computer-readable program code devices configured to receive an application description file containing a definition of a component-based application;

computer-readable program code devices configured to generate, in a memory, a representation of a parse tree based on the application description file, the parse tree comprising at least one leaf;

computer-readable program code devices configured to, for each of a first subset of the leaves, map the leaf to a target class; and

instantiate a component associated with the target class; and

computer-readable program code devices configured to, for at least a subset of the instantiated components, invoke at least one method of the component to launch the application.

20. The computer-readable medium of claim 19, wherein an element includes an attribute list comprising at least one attributes, further comprising:

computer-readable program code devices configured to

map at least one attribute in the attribute list to a property of the component associated with the target class to which the leaf is mapped.

21. The computer-readable medium of claim 20, wherein at least one element comprises a tag, and the computer-readable program code devices configured to map the element to a target class comprise:

computer-readable program code devices configured to compare the tag of the element with a plurality of target class names in an application framework; and

computer-readable program code devices configured to select a target class with a matching name.

22. The computer-readable medium of claim 19, wherein the computer-readable program code devices configured to instantiate a component of the target class comprise:

computer-readable program code devices configured to create an element processor for the element, the element processor being associated with the target class; and

computer-readable program code devices configured to create an uninitialized instance of the target class.

23. The computer-readable medium of claim 20, wherein an attribute comprises a name, and the computer-readable program code devices configured to map at least one attribute in the attribute list to a property of the component comprise:

computer-readable program code devices configured, for each attribute in the attribute list, to;

search an element mapper for a property descriptor having a name that matches the name of the attribute;

responsive to a match being found, obtain a write method for the component property from the matching property descriptor; and

execute the write method to write the attribute to the component property.

24. The computer-readable medium of claim 19, further comprising:

computer-readable program code devices configured, for each component, to;

initialize the component; and

responsive to the component having a parent component, add the component to the parent component.