Page sub-component prerequisite control mechanism

A method of presenting a page requested by a user comprising:

• in response to a request for a destination page of a graphical user interface (GUI), creating an instance of a container to represent the destination page, the container including a list of sub-components to render;
• identifying one or more sub-components associated with the destination page by executing a method of the container;
• for each of the one or more sub-components, determining whether the sub-component has any page sub-component prerequisites with reference to a set of prerequisite information, the set of prerequisite information including information regarding sub-components of the GUI that are prerequisites to other sub-components of the GUI, and if the sub-component has a page sub-component prerequisite and if one or more requirements of the page sub-component prerequisite remains unsatisfied, then adding an instance of the page sub-component prerequisite to the list of sub-components associated with the container, otherwise adding an instance of the sub-component to the list of sub-components;
• and
• causing the destination page to be displayed by rendering the output of the instances on the list of sub-components, whereby page sub-component prerequisites that have one or more requirements that remain unsatisfied are displayed in place of the corresponding sub-components, wherein the rendering is performed by invoking an execution of a method of an object corresponding to an instance of the list of sub-components associated with the container.

A graphical user interface (GUI) system for enforcing page sub-component prerequisites comprising:

• a properties data store including information regarding page sub-components of the GUI that are prerequisites to other page sub-components of the GUI;
• a base agent to respond to requests for a destination page of the GUI, in response to a request for the destination page, the base agent creating an instance of a container to represent the destination page and initiating display of the destination page after a list of page sub-components of the container has been populated by invoking an execution of a method of an object corresponding to each page sub-component of the list in the container;
• and
• a sub-component prerequisite factory decoupling the page sub-components from their respective page sub-component prerequisites, the sub-component prerequisite factory to either (1) cause an instance of an identified page sub-component prerequisite to be added to the list of page sub-components if it determines that one or more requirements of the identified page sub-component prerequisite are unsatisfied or (2) cause an instance of the page sub-component to be added to the list of page sub-components, whereby page sub-component prerequisites that have one or more unsatisfied requirements are displayed in place of the corresponding page sub-components.

A machine-readable medium having stored thereon data representing sequences of instructions, the sequences of instruction which, when executed by a processor, cause the processor to:

• identify one or more page sub-component prerequisites of page sub-components associated with a destination page of a graphical user interface (GUI) in response to a request for the destination page and with reference to the prerequisite information regarding page sub-components of the GUI that are prerequisites to other page sub-components of the GUI;
• determine whether one or more requirements of an instance of an identified page sub-component prerequisite have been satisfied by invoking a method of the instance that causes stored information regarding the state of the page sub-component prerequisite to be retrieved from a current context;
• and
• cause the destination page to be displayed with (1) content associated with the identified page sub-component prerequisite if any of its one or more requirements have not been satisfied and (2) content associated with those of the page sub-components having no page sub-component prerequisites or having page sub-component prerequisites whose requirements have all been satisfied.