Write library version in build files

[tsauerwein]

This PR adds the most recent Git tag (git describe --tags) to the build files.

The ol.js now looks like this:

// OpenLayers 3. See http://ol3.js.org/
// Version: v3.0.0-gamma.3
(function(){var ...

And ol-debug.js:

// OpenLayers 3. See http://ol3.js.org/
// Version: v3.0.0-gamma.3
var CLOSURE_NO_DEPS = true;
...

If there are further commits after the tag, you will also see the last commit. For example, after I made this commit, the version changed to v3.0.0-gamma.3-1-g076f53c.

Note that you'll have to run git fetch upstream --tags to get all remote tags.

closes #1792

[marcjansen]

Great! 👍 Plus one for merging this.

Do we have any chance that this could also be added to the library as a property?

Maybe via appending sth. to the final output:

// compiled output including 
// ol.version=null;
})(); // end of wrapping IIFE
ol.version='v3.0.0-gamma.3';

or via a simple search and replace?

I am just thinking out loud here.

[ahocevar]

@marcjansen I don't think it will be necessary to add this as property to the library. Someone who can read out the property can also look at the first lines of the js file.

[tonio]

Someone who can read out the property can also look at the first line of the js file.

+1

[probins]

looks like this assumes that Git is installed, which may not be the case

[probins]

it would be nice to have the closure library/compiler version too #1192 (comment)

[tsauerwein]

@probins Now it will also work properly when Git is not installed (or when the git describe --tags command fails, for whatever reason). Thanks for the hint!

About the Closure library/compiler version: If you have the ol3 version or commit, don't you implicitly know the Closure version? Because the Closure version is specified in one of the configuration files.

[marcjansen]

I still think it is very useful to have the version at hand inside a library property. It's more convenient and allows other libraries on top of ol to react according to a version. AFAIK most libraries provide sth. like this.

This discussion shouldn't block this PR from being merged, though.

Please merge, @tsauerwein.

[probins]

If you have the ol3 version or commit, don't you implicitly know the Closure version? Because the Closure version is specified in one of the configuration files.

don't think so. You could, assuming you have git installed, checkout a new branch for that commit-ish, and look in closure-util.json for the library, but that doesn't tell you the compiler version, and it's not particularly intuitive. See #2445 for a fix

Thanks for tackling this btw. It's been on my list for a long time.

[tschaub]

Is options defined here? This doesn't look correct to me.

[tschaub]

I see that options is defined above. I'm going to put together a change that makes this more explicit though.

[tschaub]

We use lowercase for primitive types (e.g. string).

[tschaub]

If you have the ol3 version or commit, don't you implicitly know the Closure version? Because the Closure version is specified in one of the configuration files.

I agree with this. Let's stick with one version. The others can be looked up.

[tschaub]

@tsauerwein hope my comments above make sense. I've incorporated them into #2446.

Thanks for adding this in, I like it. I imagine we may want another way to insert version information (the hosted build tool for example will not be using git clones), but that can be addressed separately (e.g. with a build option).

[tsauerwein]

@tschaub Thanks for your corrections! I was a bit fast with merging, sorry...