Abstract: Property modifiers stored on a computer-readable medium for formatting information associated with a computer file, such as an electronic document. Each property modifier includes a size field having information indicating the size of its property modifier argument and an index field having an index into a property information array. A program module can traverse a group of property modifiers by utilizing the information in the size field of the current property modifier to determine the location of the next property modifier. Formatting is applied to information of the computer file by using the index of each property modifier to access formatting information maintained in the property information array. Each property modifier can store encoded information corresponding to the type of object to receive formatting, the size of the property modifier's argument, and an index into the property information array associated with an executable computer program.

Abstract: A method and apparatus for locating and for maintaining the locations of files within a directory tree structure. A file location request is received from a program module and a response is generated containing a file location identifying the location of one or more files within a directory tree structure. The file location request contains search criteria that identifies at least one file. If the file location of the component file has changed or has never been searched, then an attempt is made to locate the file and the new file location is returned. All file locations are stored in a file location cache so that subsequent searches can be minimized. When either the search criteria does not exist in the file location cache or the directory originally containing the sought file has been modified, the requested file location is searched for and the file location cache is updated.

Abstract: Formatting information in a program module, particularly useful for word processing and similar text processing programs. A property information array stored in association with an executable program module contains formatting for applying to information in a document comprising a data structure and a property modifier structure. The data structure stores data elements corresponding to the information in the document to be formatted, e.g., a text file. The property modifier structure stores groups of data formatting property modifiers and their arguments that represent the appearance of the data elements, e.g., a character property, a paragraph property, a section property, etc. Each property modifier contains encoded format-related information and comprises an argument size field having information indicating the size of the property modifier argument and a unique identification field, i.e., an index into the property information array. A selected data element may be displayed, printed, etc.

Abstract: A method and system for preserving document integrity between potentially partially incompatible versions of a program module by maintaining forwards compatibility and backwards compatibility. Version (n') of the program module is released after version (n). A "saved by version (n)" bit may be activated any time that version (n) saves a file. The "saved by version (n)" bit indicates to subsequently-released versions, such as version (n'), that the file has been saved by version (n) and, based upon this information, appropriate action should be taken by the subsequently-released version. A "warning from future version" bit may be activated to indicate that a feature or features of the subsequently-released version is not supported by version (n). Based upon receiving this bit, version (n) may open the file with these features disabled or may take some other appropriate action.

Abstract: A method is disclosed for integrating a plurality of discrete subprograms with a main program. The method enables the main program to integrate any discrete subprogram stored in its directory with the main program. The method includes the step of identifying each discrete subprogram stored in the directory of the main program and creating a cross reference array to enable the main program to access the plurality of subprograms. In addition to creating the cross reference array, an event reference list of the main program is updated, enabling commands of the subprogram to be given key and menu assignments, thereby further integrating the subprogram with the main program. Similarly, the subprogram can be removed from the main program simply by deleting the subprogram from the directory of the main program.