Unregistering a File Writer
If you are creating a new iTool from an existing iTool class, you may want to remove a file writer registered for the existing class from your new tool. This can be useful if you have an iTool class that implements all of the functionality you need, but which registers a file writer you don't want included in your iTool. Rather than recreating the iTool class to remove the file writer, you could create your new iTool class in such a way that it inherits from the existing iTool class, but unregisters the unwanted file writer.
Unregister a file writer by calling the IDLitTool::UnregisterFileWriter method in the Init method of your iTool class:
where identifier is the string name used when registering the file writer.
For example, suppose you are creating a new iTool that subclasses from a standard iTool that is based on the IDLitToolbase class. If you wanted your new tool to behave just like a standard tool, with the exception that it would not export PNG files, you could include the following method call in your iTool's Init method:
Finding the Identifier String
To find the string value used as the identifier parameter to the UnregisterFileWriter method, you can inspect the class file that registers the file writer (if the file writer is registered by a user-created class), or use the FindIdentifiers method of the IDLitTool object to generate a list of registered file writers. (Standard iTool file writers are pre-registered within the iTool framework.)
If the file writer is registered in a user-created class, you could inspect the class definition file to find a call to the RegisterFileWriter method, which looks something like this:
The first argument to the RegisterFileWriter method ('PNG File Writer') is the string name of the file writer.
Alternatively, to generate a list of relative identifiers for all file writers registered with the current tool, use the following statements:
void = IGETCURRENT(TOOL=oTool) fwlist = oTool->FindIdentifiers(/FILE_WRITERS) FOR i = 0, N_ELEMENTS(fwlist)-1 DO PRINT, $ STRMID(fwlist[i], STRPOS(fwlist[i], '/', /REVERSE_SEARCH)+1)
See "IDLitTool::FindIdentifiers" (IDL Reference Guide) for details.
