Angular service promise caching

service.coffee

  getResponse = (method, type, params) =>

    @promises ||= {}
    promiseKey = (method + type + JSON.stringify params).replace(/[\{\}",:\-\._\[\] ]/g, '')
    return @promises[promiseKey] if @promises[promiseKey]
    console.log promiseKey
    deferred = $q.defer()

    params ||= {}
    params.access_token = contentfulConfig.access_token

    url = "#{contentfulConfig.protocol}://#{contentfulConfig.host}/spaces/#{contentfulConfig.space}"
    url += "/#{type}" if type

    query = []
    for key of params
      query.push("#{key}=#{params[key]}") if params.hasOwnProperty(key)
    url += "?#{query.join('&')}" if query.length>0
    
    $http({
      method: method,
      url: url
    })
      .then(
        (response) ->
          deferred.resolve processResponse(response.data)
        (error) ->
          deferred.reject error
      )
      .finally => delete @promises[promiseKey]

    @promises[promiseKey] = deferred.promise