class app.collections.Docs extends app.Collection  @model: 'Doc'   findBySlug: (slug) ->    @findBy('slug', slug) or @findBy('slug_without_version', slug)   NORMALIZE_VERSION_RGX = /\.(\d)$/  NORMALIZE_VERSION_SUB = '.0$1'  sort: ->    @models.sort (a, b) ->      if a.name is b.name        if not a.version or a.version.replace(NORMALIZE_VERSION_RGX, NORMALIZE_VERSION_SUB) > b.version.replace(NORMALIZE_VERSION_RGX, NORMALIZE_VERSION_SUB)          -1        else          1      else if a.name.toLowerCase() > b.name.toLowerCase()        1      else        -1   # Load models concurrently.  # It's not pretty but I didn't want to import a promise library only for this.  CONCURRENCY = 3  load: (onComplete, onError, options) ->    i = 0     next = =>      if i < @models.length        @models[i].load(next, fail, options)      else if i is @models.length + CONCURRENCY - 1        onComplete()      i++      return     fail = (args...) ->      if onError        onError(args...)        onError = null      next()      return     next() for [0...CONCURRENCY]    return   clearCache: ->    doc.clearCache() for doc in @models    return   uninstall: (callback) ->    i = 0    next = =>      if i < @models.length        @models[i++].uninstall(next, next)      else        callback()      return    next()    return   getInstallStatuses: (callback) ->    app.db.versions @models, (statuses) ->      if statuses        for key, value of statuses          statuses[key] = installed: !!value, mtime: value      callback(statuses)      return    return   checkForUpdates: (callback) ->    @getInstallStatuses (statuses) =>      i = 0      if statuses        i += 1 for slug, status of statuses when @findBy('slug', slug).isOutdated(status)      callback(i)      return    return   updateInBackground: ->    @getInstallStatuses (statuses) =>      return unless statuses      for slug, status of statuses        doc = @findBy 'slug', slug        doc.install($.noop, $.noop) if doc.isOutdated(status)      return    return