Merge pull request #50 from topcoder-platform/develop

Improvements to listings

Author: ajefts

src/shared/actions/challenge-listing.js

@@ -1,13 +1,133 @@
 /**
  * Challenge listing actions.
+ *
+ * In the Redux state we keep an array of challenge objects loaded into the
+ * listing(s), and a set of UUIDs of pending requests to load more challenges.
+ * To load more challenges you should first dispatch GET_INIT action with some
+ * UUID (use shortid package to generate it), then one of GET_CHALLENGES,
+ * GET_MARATHON_MATCHES, GET_USER_CHALLENGES, or GET_USER_MARATHON_MATCHES
+ * actions with the same UUID and a set of authorization, filtering, and
+ * pagination options. Received challenges will be merged into the array of
+ * challenges stored in the state, with some filtering options appended to the
+ * challenge objects (so that we can filter them again at the frontend side:
+ * challenge objects received from the backend do not include some of the
+ * necessary data, like groupIds, lists of participating users, etc).
+ *
+ * RESET action allows to remove all loaded challenges and cancel any pending
+ * requests to load challenges (removing an UUID from the set of pending
+ * requests results in ignoring the response for that request).
+ *
+ * The backend includes into each response the total count of challenges
+ * matching the specified filtering options (the actual number of challenge
+ * objects included into the response might be smaller, due to the pagination
+ * params). If "count" argument was provided in the dispatched action,
+ * the total count of matching challenges from the response will be written
+ * into a special map of counts in the Redux state.
  */
 
-import _ from 'lodash';
+import logger from 'utils/logger';
 import { createActions } from 'redux-actions';
-// import { getService } from 'services/challenges';
+import { getService } from 'services/challenges';
+
+/**
+ * Private. Common processing of promises returned from ChallengesService.
+ * @param {Object} promise
+ * @param {String} uuid
+ * @param {Object} filters
+ * @param {Object} countCategory
+ * @param {String} user
+ * @return {Promise}
+ */
+function handle(promise, uuid, filters, countCategory, user) {
+  return promise.catch((error) => {
+    logger.error(error);
+    return {
+      challenges: [],
+      totalCount: 0,
+    };
+  }).then(res => ({
+    challenges: res.challenges,
+    filters,
+    totalCount: countCategory ? {
+      category: countCategory,
+      value: res.totalCount,
+    } : null,
+    user: user || null,
+    uuid,
+  }));
+}
+
+/**
+ * Gets a portion of challenges from the backend.
+ * @param {String} uuid Should match an UUID stored into the state by
+ *  a previously dispatched GET_INIT action. Reducer will ignore the challenges
+ *  loaded by this action, if the UUID has already been removed from the set of
+ *  UUIDs of pending fetch challenge actions. Also, once the action results are
+ *  processed, its UUID is removed from the set of pending action UUIDs.
+ * @param {Object} filters Optional. An object with filters to pass to the
+ *  backend.
+ * @param {Object} params Optional. An object with params to pass to the backend
+ *  (except of the filter param, which is set by the previous argument).
+ * @param {String} token Optional. Auth token for Topcoder API v3. Some of the
+ *  challenges are visible only to the properly authenticated and authorized
+ *  users. With this argument omitted you will fetch only public challenges.
+ * @param {String} countCategory Optional. Specifies the category whereh the
+ *  total count of challenges returned by this request should be written.
+ * @param {String} user Optional. User handle. If specified, only challenges
+ *  where this user has some role are loaded.
+ * @return {Promise}
+ */
+function getChallenges(uuid, filters, params, token, countCategory, user) {
+  const service = getService(token);
+  const promise = user ?
+    service.getUserChallenges(user, filters, params) :
+    service.getChallenges(filters, params);
+  return handle(promise, uuid, filters, countCategory, user);
+}
+
+/**
+ * Writes specified UUID into the set of pending requests to load challenges.
+ * This allows (1) to understand whether we are waiting to load any challenges;
+ * (2) to cancel pending request by removing UUID from the set.
+ * @param {String} uuid
+ */
+function getInit(uuid) {
+  return uuid;
+}
+
+/**
+ * Gets a portion of marathon matches from the backend. Parameters are the same
+ * as for getChallenges() function.
+ * @param {String} uuid
+ * @param {Object} filters
+ * @param {Object} params
+ * @param {String} token
+ * @param {String} countCategory
+ * @param {String} user Optional. User handle. If specified, only challenges
+ *  where this user has some role are loaded.
+ * @param {Promise}
+ */
+function getMarathonMatches(uuid, filters, params, token, countCategory, user) {
+  const service = getService(token);
+  const promise = user ?
+    service.getUserMarathonMatches(user, filters, params) :
+    service.getMarathonMatches(filters, params);
+  return handle(promise, uuid, filters, countCategory, user);
+}
+
+/**
+ * This action tells Redux to remove all loaded challenges and to cancel
+ * any pending requests to load more challenges.
+ */
+function reset() {
+  return undefined;
+}
 
 export default createActions({
   CHALLENGE_LISTING: {
-    REMOVE_ALL_CHALLENGES: _.noop,
+    GET_CHALLENGES: getChallenges,
+    GET_INIT: getInit,
+    GET_MARATHON_MATCHES: getMarathonMatches,
+    RESET: reset,
   },
 });