Pattern tags in group names

[jirenius]

Issue

It should be possible to use parts of the resource name when defining worker groups.

Example
Lets say we have a resource pattern, test.user.$userId, which might have sub-resources, test.user.$userId.roles.

If the data is stored and updated together, we might want only a single worker goroutine for each user and their sub-data. But in order not to have a single worker for all users, we need to be able to use the $userId part in the group ID.

Solution

Let groups contain tags, ${tagName}. The tagName must match a parameter in the resource pattern.

Example:

s.Handle("article.$id",
    res.Access(res.AccessGranted),
    res.GetModel(func(r res.ModelRequest) {
        article := getArticle(r.PathParam("id"))
        if article == nil {
            r.NotFound()
        } else {
            r.Model(article)
        }
    }),
    res.Group("group.article.${id}"),
)

[jirenius]

Resolved in #27