Re: Question about OpenDocument API development

On Tue, 2009-06-23 at 07:45 +0200, Christian Weiske wrote: > Hi all, > > > I'm making progress in understanding the OpenDocument package, reorganizing it and fixing > bugs in it. While tinkering with new content types (e.g. lists and images), I found that he current > API approach does not suffice. Let me explain: > > - class OpenDocument_Text has two methods regarding adding content: createHeading and > createParagraph > - OpenDocument_Element_Paragraph has createSpan, createHyperlink, createText > - OpenDocument_Element_Heading has createSpan, createHyperlink, createText > - all of them should support createBookmark which they don't do yet. Potentially all of > them will be able to get images added to. > > Currently, every single element class (+ the opendocument one) implements the create*() methods > itself, redirecting the calls to the element::instance() methods. What I don't like is that, > when adding support for a new element - e.g. lists - I have to do this in every single element class > that supports it! > > So there needs to be a better way - for example using __call and throwing exceptions in the > cases the element-to-be-created is not supported. I could also try to find class hierarchies with > elements that are supported in certain classes only, and base them all off a common element class. > The problem with that approach is that I don't know yet if that hierarchy is tree-like or not. > I could also do take the quickform approach and use a general create('elementtype', > $params) function - as flexible as __call, but not very usable from a user's point of view in > regard of capturing the supported parameters. > > What would you do? > >From your quick examples, it looks like the dependency chain will have a lot of loops (text->createHeading, heading->createText). A class hierarchy might not work in this case. Instead, I would suggest something like the following mockup: http://labs.silverorange.com/files/OpenDocument/class-mockup.phps Each element would have a corresponding creator class. Each element class would also define a list of supported creators and the correct one is called using __call(). I haven't looked at OpenDocument's code at all, so I may just be spouting crazy talk! Cheers, Mike