The generate-symbols.js task runs JSDoc on source files. Because this takes a long time (13s) to run on the whole library, the resulting symbols file includes additional metadata to make it possible to do incremental symbol generation on subsequent runs. The 'path' and 'extends' metadata for a symbol are used to determine what needs to be regenerated.
There are cases where a private class may inherit an exportable member (e.g. ol.DebugTile_#getTileCoord comes from ol.Tile#getTileCoord). We want to avoid making these exportable.
This generates info for all symbols annotated with "@todo api" (when Plovr is replaced, this will become "@api"). Generated metadata is written to stdout. A separate process will handle the output.
The single externs/olx.js file describes all of the "options" objects we accept in our constructors. The @typedef annotations are used by the compiler for type checking. The @type annotations include documentation for individual options and serve as externs when compiling a profile of the library. When compiling an application together with the library, the externs/olx.js file is included as one of the sources to provide the @typedef's without generating externs.
If we want to maintain multiple src/*.externs.js files instead of one large externs/olx.js file, we can. But while we are still using Plovr, it makes for easier build configurations to have one file.
This removes the build tasks that generated the build/src/external/src/externs/types.js and build/src/internal/src/types.js files as those are both replaced by the single externs/olx.js file.
This is needed because the current version of closure compiler we use does not
include externs for valueAsNumber which we now use in ol.dom.Input.
So this backports patch from issue:
https://code.google.com/p/closure-compiler/issues/detail?id=1060
This patch should be reverted when the next closure compiler release is out
with valueAsNumber externs.
