Metric Feature Tags

To help find metrics in the Glean Dictionary and other tools, metrics should contain tag metadata corresponding to the feature area(s) that they belong to. In the case of Firefox for Android, tag information is based off of the GitHub feature labels for this repository:

You can see how tag information is rendered here:

Adding feature tags to metrics

Adding tag information to a metric used to involve editing the Glean Annotations repository, but you can now add this information directly when adding or modifying metrics.yaml. Just add a section called metadata to the metric and add a list of tags that correspond to it.

For example:

    type: event
    description: |
      A user tapped the search bar
        - Search

Updating the feature tags

The set of valid tags is documented in a file called tags.yaml, but should never be updated by hand. If a feature labels is ever added or removed, you can synchronize the tags file in the source tree by running ./tools/ in the root of the repository. Note that a tag must be specified in tags.yaml for it to be usable in a metric, so if a tag is removed from tags.yaml all uses of it must be removed from metrics.yaml.