Page prerequisite control mechanism

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

• a properties data store including information regarding pages of the GUI that are prerequisites to other pages of the GUI;
• a base agent to respond to requests to display a destination page of the GUI, in response to a request to display the destination page, the base agent causing the output of the destination page to be displayed if all the requirements of one or more prerequisite pages associated with the destination page have been satisfied, otherwise causing the output of a prerequisite page of the one or more prerequisite pages to be displayed by invoking an execution of a method of an object corresponding to each page associated with the destination page;
• and
• a prerequisite factory decoupling the pages from their respective prerequisite pages, the prerequisite factory to determine whether or not requirements of one or more identified prerequisite pages have been satisfied by causing information regarding the state of the one or more identified prerequisite pages to be retrieved from a current context.

A method comprising:

• identifying, at run-time, one or more prerequisite web pages associated with a requested web page by accessing a properties file by invoking a method of a container object corresponding to the requested web page;
• the container object determining whether requirements of the one or more identified prerequisite pages have been satisfied by instantiating and executing a method of one or more prerequisite objects corresponding to the identified prerequisite pages;
• and
• causing the output of the requested web page to be displayed if all the requirements of the one or more identified prerequisite pages have been satisfied, otherwise causing the output of a prerequisite page of the one or more identified prerequisite pages having one or more unsatisfied requirements to be displayed by executing a method of an object corresponding to the prerequisite page.

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 prerequisite pages associated with a destination page by accessing a properties file in response to a request for the destination page by invoking a method of a container object corresponding to the destination page, the properties file including prerequisite information regarding pages of a graphical user interface (GUI) that are prerequisites to other pages of the GUI;
• determine using the container object which sub-component of an identified prerequisite page is capable of confirming whether or not requirements of the identified prerequisite page have been satisfied;
• determine whether the requirements of the identified prerequisite page have been satisfied by invoking from the container object a method of a component object corresponding to an instance of the sub-component that causes stored information regarding the state of the identified prerequisite page to be retrieved from a current component object, the component object being a child object of the container object;
• and
• cause the output of the destination page to be displayed if all the requirements of the one or more identified prerequisite pages have been satisfied, otherwise cause the output of a prerequisite page of the one or more identified prerequisite pages having one or more requirements that have not been satisfied to be displayed by invoking an execution of a method of the corresponding component object to stream the content to the container object.