GStreamer documentation notes IMPORTANT ========= Please make sure you've read and understood everything in this file before you try changing documentation. OVERVIEW ======== GStreamer has two sets of documentation that we maintain: * API references, using gtk-doc (gstreamer, gstreamer-libs) * "books", using DocBook/XML (faq, manual, pwg) DOCBOOK NOTES ============= OK, I've grown so tired of having to coax the docs to build every time I get round to it that I've decided to note down some of the things that are important to know. OVERVIEW -------- * Our documentation should all be Docbook/XML. No SGML. * The source for the documentation is: - one or more .xml files, with the main one being gstreamer-(whatever).xml - image files - in .fig - in .png (and maybe others) * We want to generate docs in HTML, PS and PDF * We want to use xml to to generate these CONVENTIONS ----------- We stick to some simple conventions for writing docbook documentation. * id names: - all id's start with chapter-, part-, section-, or misc- - verify this is the case by looking at the generated file names in html/ - sections should also include the chapter name; for example in a chapter called chapter-example, a section would be called section-example-hello-world HOW IMAGES ARE HANDLED ---------------------- * the format of images used is: - PNG for html - EPS for ps - PDF for pdf * images may need to be converted from their source format to the end format * a file called image.entities is generated that provides two entities: ℑ and ℑ ℑ is the file extension (png, ps, pdf) * all generated images will be put in images/ HOW THE BUILD WORKS FOR EACH FORMAT ----------------------------------- * HTML: - xmlto html gstreamer-whatever.xml should produce the html docs. - We do this in the html subdir of the doc builddir. - images are copied to (builddir)/html/images - PNGS should be set to all of the png's referenced for html, both already there and auto-generated * PS : - images are converted to .ps files in EPS format. Generated images are put in images/ - xmlto ps gstreamer-whatever.xml generates the ps file * PDF : There are two ways: - ps2pdf is the easiest - we specify ps, PS as the image type, but using xmlto the build will fail because it uses ps2pdf internally and it fails to generate the images By hand-generating .pdf images before xmlto we can make the build succeed. (This is why image-pdf has file ext pdf but type EPS; this tricks xmlto in doing the right thing) xmlto pdf gstreamer-whatever.xml generates pdf (but seems to fail on the FAQ, so for now we use ps2pdf) HOW THE BUILD SYSTEM IS SET UP ------------------------------ * make all should build html, ps, and pdf * html is built in a subdir, with the png/ps images copied there * ps and pdf are built in the current dir, in one file DOCBOOK NOTES ============= * spell checking with aspell * aspell -b -c --mode=sgml --lang=en .xml unfortunately the curses-ui of aspell (0.50.5) has problems with the xml tags GTK-DOC NOTES ============= * files under CVS control: - Makefile.am - gstreamer-sections.txt describes which symbols later appear on one api-doc page configure which symbols are shown/invisible/private - gstreamer.types the types file lists all get_type() functions that register the GObject types - gstreamer-docs.sgml defines the overall structure of the api documentation - tmpl/ - only add the file to CVS if you have at least filled the short description (filename corresponds to the tag in the sections file) - document as much as possible in the source (*.c files) * what to do when adding a new piece of API: - add both an entity and use the entity in gstreamer-docs.sgml - add a new
to gstreamer-sections.txt in the correct alphabetical position related to the other sections (so that it is easier to locate) - add all documented symbols to gstreamer-sections.txt in the proper section (default),, - document at least the Short_Description in tmpl/.sgml - signals: document them properly in tmpl/.sgml (or better in the c-source) * checklist: - make sure *-sections.txt has a set for each <FILE> - add only *one* <TITLE> to each file, when you have multiple classes in one source-file, create one <FILE> section for each class - the <TITLE> *must* be named like the type of the GType, when it gets registered (otherwise gtkdoc introspection fails) - for clarity name the <FILE> like the <TITLE>, but all lowercase * what to do when trying to improve the docs - compare the output of grep "_get_type" gstreamer-sections.txt | sort with the types in XXX.types to detect entries that are maybe missing * what happens during a gtk-doc build ? - headers are scanned based on $(MODULE).types $(MODULE)-scan is created gtkdoc-scan is called with a sourcedir and a module name, where the module name is $(MODULE) $(MODULE)-sections.txt is created if it doesn't exist yet (it should), as well as $(MODULE)-decl.txt and $(MODULE)-decl-list.txt and .args, .hierarchy and .signals files are created gtkdoc-scan is called - if it not works, try e.g. 'rm docs/gst/*.stamp' * Possible errors and how to fix them - Warning: multiple "IDs" for constraint linkend: gst-tag-register. - check if gst_tag_register is listed more than once in -sections.txt WEBSITE DOCUMENTATION ===================== Updating the online documentation is pretty simple. Make sure that you a) have a working freedesktop.org account b) $HOME/.ssh/config set up so that it has the right User for the Host (for example, I have: Host freedesktop.org User thomasvs c) verify this works by doing ssh freedesktop.org and being logged in without a password prompt d) have verified your changes build documentation locally. Then, after updating any of the docs, run "make upload" from that directory. Or, run "make upload" from this (docs) directory. RANDOM THINGS I'VE LEARNED ========================== * for clean builddir != srcdir separation, I wanted to use xmlto --searchpath so the source xml could find the built entity file. But xmlto --searchpath is (right now) for TeX input, not xml input. xsltproc has a --path option (that xmlto doesn't use yet), but it resolves single files to $(specified_path)/$(srcdir)/$(file) For now, we need to hack around it by copying xml to the build dir.