Grabbing the latest version number from a GitHub repository
I have several GitHub repositories, where some have a gh-pages branch with a public web site. On these web sites, I want to show and link to the latest version.
When I present the repository, I also want to make it easy to download the latest release. I therefore have a download button in which I want to show the latest version number.
To do this, I just use the GitHub API. Let’s say that we create a 2.1 version of a library. We would then create and and push a tag to GitHub:
git tag 2.1
git push origin 2.1
Once the tag is pushed, we can use the GitHub API to show & download the latest version.
Use the GitHub API to grab all tags
The GitHub API let’s you do a lot. You can find all the information you need here. With this, I decided to try fitzgen’s JavaScript github-api library to integrate with the API.
For instance, you just have write the following to grab all tags for a certain repository:
var repo = new gh.repo("danielsaidi", "Facadebook");
repo.tags(function(result){ alert(JSON.stringify(result)); });
Since I will use this approach for all GitHub repositories, I decided to package my custom script according to the rest of the JavaScript library.
I thus created another async method for the gh.repo prototype, like this:
gh.repo.prototype.getLatestRelease = function(callback) {
this.tags(function(result) {
var latest = "";
for (var prop in result.tags) {
if (prop > latest) {
latest = prop;
}
}
callback(latest);
});
}
Each site has a span element with the id version, which I can then modify like this:
$(document).ready(function() {
var repo = new gh.repo("danielsaidi", "Facadebook");
var tag = repo.getLatestRelease(function(result){ $("#version").html(result); });
// Apply the tag to the #version span
});
When the page loads, the script loads all available repository tags, iterates over them and grab the latest tag. The result is rather nice:
This means that all repository web pages can feature a nice download button that shows the latest version number, just like other libraries like jQuery does.