Add ability to follow hashtags in web UI (#18862)

app/javascript/mastodon/actions/tags.js

+import api from '../api';
+
+export const HASHTAG_FETCH_REQUEST = 'HASHTAG_FETCH_REQUEST';
+export const HASHTAG_FETCH_SUCCESS = 'HASHTAG_FETCH_SUCCESS';
+export const HASHTAG_FETCH_FAIL    = 'HASHTAG_FETCH_FAIL';
+
+export const HASHTAG_FOLLOW_REQUEST = 'HASHTAG_FOLLOW_REQUEST';
+export const HASHTAG_FOLLOW_SUCCESS = 'HASHTAG_FOLLOW_SUCCESS';
+export const HASHTAG_FOLLOW_FAIL    = 'HASHTAG_FOLLOW_FAIL';
+
+export const HASHTAG_UNFOLLOW_REQUEST = 'HASHTAG_UNFOLLOW_REQUEST';
+export const HASHTAG_UNFOLLOW_SUCCESS = 'HASHTAG_UNFOLLOW_SUCCESS';
+export const HASHTAG_UNFOLLOW_FAIL    = 'HASHTAG_UNFOLLOW_FAIL';
+
+export const fetchHashtag = name => (dispatch, getState) => {
+  dispatch(fetchHashtagRequest());
+
+  api(getState).get(`/api/v1/tags/${name}`).then(({ data }) => {
+    dispatch(fetchHashtagSuccess(name, data));
+  }).catch(err => {
+    dispatch(fetchHashtagFail(err));
+  });
+};
+
+export const fetchHashtagRequest = () => ({
+  type: HASHTAG_FETCH_REQUEST,
+});
+
+export const fetchHashtagSuccess = (name, tag) => ({
+  type: HASHTAG_FETCH_SUCCESS,
+  name,
+  tag,
+});
+
+export const fetchHashtagFail = error => ({
+  type: HASHTAG_FETCH_FAIL,
+  error,
+});
+
+export const followHashtag = name => (dispatch, getState) => {
+  dispatch(followHashtagRequest(name));
+
+  api(getState).post(`/api/v1/tags/${name}/follow`).then(({ data }) => {
+    dispatch(followHashtagSuccess(name, data));
+  }).catch(err => {
+    dispatch(followHashtagFail(name, err));
+  });
+};
+
+export const followHashtagRequest = name => ({
+  type: HASHTAG_FOLLOW_REQUEST,
+  name,
+});
+
+export const followHashtagSuccess = (name, tag) => ({
+  type: HASHTAG_FOLLOW_SUCCESS,
+  name,
+  tag,
+});
+
+export const followHashtagFail = (name, error) => ({
+  type: HASHTAG_FOLLOW_FAIL,
+  name,
+  error,
+});
+
+export const unfollowHashtag = name => (dispatch, getState) => {
+  dispatch(unfollowHashtagRequest(name));
+
+  api(getState).post(`/api/v1/tags/${name}/unfollow`).then(({ data }) => {
+    dispatch(unfollowHashtagSuccess(name, data));
+  }).catch(err => {
+    dispatch(unfollowHashtagFail(name, err));
+  });
+};
+
+export const unfollowHashtagRequest = name => ({
+  type: HASHTAG_FETCH_REQUEST,
+  name,
+});
+
+export const unfollowHashtagSuccess = (name, tag) => ({
+  type: HASHTAG_FETCH_SUCCESS,
+  name,
+  tag,
+});
+
+export const unfollowHashtagFail = (name, error) => ({
+  type: HASHTAG_FETCH_FAIL,
+  name,
+  error,
+});

app/javascript/mastodon/features/hashtag_timeline/index.js

 import React from 'react';
 import { connect } from 'react-redux';
 import PropTypes from 'prop-types';
+import ImmutablePropTypes from 'react-immutable-proptypes';
 import StatusListContainer from '../ui/containers/status_list_container';
-import Column from '../../components/column';
-import ColumnHeader from '../../components/column_header';
+import Column from 'mastodon/components/column';
+import ColumnHeader from 'mastodon/components/column_header';
 import ColumnSettingsContainer from './containers/column_settings_container';
-import { expandHashtagTimeline, clearTimeline } from '../../actions/timelines';
-import { addColumn, removeColumn, moveColumn } from '../../actions/columns';
-import { FormattedMessage } from 'react-intl';
-import { connectHashtagStream } from '../../actions/streaming';
+import { expandHashtagTimeline, clearTimeline } from 'mastodon/actions/timelines';
+import { addColumn, removeColumn, moveColumn } from 'mastodon/actions/columns';
+import { injectIntl, FormattedMessage, defineMessages } from 'react-intl';
+import { connectHashtagStream } from 'mastodon/actions/streaming';
 import { isEqual } from 'lodash';
+import { fetchHashtag, followHashtag, unfollowHashtag } from 'mastodon/actions/tags';
+import Icon from 'mastodon/components/icon';
+import classNames from 'classnames';
+
+const messages = defineMessages({
+  followHashtag: { id: 'hashtag.follow', defaultMessage: 'Follow hashtag' },
+  unfollowHashtag: { id: 'hashtag.unfollow', defaultMessage: 'Unfollow hashtag' },
+});
 
 const mapStateToProps = (state, props) => ({
   hasUnread: state.getIn(['timelines', `hashtag:${props.params.id}${props.params.local ? ':local' : ''}`, 'unread']) > 0,
+  tag: state.getIn(['tags', props.params.id]),
 });
 
 export default @connect(mapStateToProps)
+@injectIntl
 class HashtagTimeline extends React.PureComponent {
 
   disconnects = [];
@@ -25,7 +36,9 @@ class HashtagTimeline extends React.PureComponent {
     columnId: PropTypes.string,
     dispatch: PropTypes.func.isRequired,
     hasUnread: PropTypes.bool,
+    tag: ImmutablePropTypes.map,
     multiColumn: PropTypes.bool,
+    intl: PropTypes.object,
   };
 
   handlePin = () => {
@@ -39,7 +52,8 @@ class HashtagTimeline extends React.PureComponent {
   }
 
   title = () => {
-    let title = [this.props.params.id];
+    const { id } = this.props.params;
+    const title  = [id];
 
     if (this.additionalFor('any')) {
       title.push(' ', <FormattedMessage key='any' id='hashtag.column_header.tag_mode.any'  values={{ additional: this.additionalFor('any') }} defaultMessage='or {additional}' />);
@@ -95,23 +109,34 @@ class HashtagTimeline extends React.PureComponent {
     this.disconnects = [];
   }
 
-  componentDidMount () {
+  _unload () {
+    const { dispatch } = this.props;
+    const { id, local } = this.props.params;
+
+    this._unsubscribe();
+    dispatch(clearTimeline(`hashtag:${id}${local ? ':local' : ''}`));
+  }
+
+  _load() {
     const { dispatch } = this.props;
     const { id, tags, local } = this.props.params;
 
     this._subscribe(dispatch, id, tags, local);
     dispatch(expandHashtagTimeline(id, { tags, local }));
+    dispatch(fetchHashtag(id));
   }
 
-  componentWillReceiveProps (nextProps) {
-    const { dispatch, params } = this.props;
-    const { id, tags, local } = nextProps.params;
+  componentDidMount () {
+    this._load();
+  }
+
+  componentDidUpdate (prevProps) {
+    const { params } = this.props;
+    const { id, tags, local } = prevProps.params;
 
     if (id !== params.id || !isEqual(tags, params.tags) || !isEqual(local, params.local)) {
-      this._unsubscribe();
-      this._subscribe(dispatch, id, tags, local);
-      dispatch(clearTimeline(`hashtag:${id}${local ? ':local' : ''}`));
-      dispatch(expandHashtagTimeline(id, { tags, local }));
+      this._unload();
+      this._load();
     }
   }
 
@@ -124,15 +149,40 @@ class HashtagTimeline extends React.PureComponent {
   }
 
   handleLoadMore = maxId => {
-    const { id, tags, local } = this.props.params;
-    this.props.dispatch(expandHashtagTimeline(id, { maxId, tags, local }));
+    const { dispatch, params } = this.props;
+    const { id, tags, local }  = params;
+
+    dispatch(expandHashtagTimeline(id, { maxId, tags, local }));
+  }
+
+  handleFollow = () => {
+    const { dispatch, params, tag } = this.props;
+    const { id } = params;
+
+    if (tag.get('following')) {
+      dispatch(unfollowHashtag(id));
+    } else {
+      dispatch(followHashtag(id));
+    }
   }
 
   render () {
-    const { hasUnread, columnId, multiColumn } = this.props;
+    const { hasUnread, columnId, multiColumn, tag, intl } = this.props;
     const { id, local } = this.props.params;
     const pinned = !!columnId;
 
+    let followButton;
+
+    if (tag) {
+      const following = tag.get('following');
+
+      followButton = (
+        <button className={classNames('column-header__button')} onClick={this.handleFollow} title={intl.formatMessage(following ? messages.unfollowHashtag : messages.followHashtag)} aria-label={intl.formatMessage(following ? messages.unfollowHashtag : messages.followHashtag)} aria-pressed={following ? 'true' : 'false'}>
+          <Icon id={following ? 'user-times' : 'user-plus'} fixedWidth className='column-header__icon' />
+        </button>
+      );
+    }
+
     return (
       <Column bindToDocument={!multiColumn} ref={this.setRef} label={`#${id}`}>
         <ColumnHeader
@@ -144,6 +194,7 @@ class HashtagTimeline extends React.PureComponent {
           onClick={this.handleHeaderClick}
           pinned={pinned}
           multiColumn={multiColumn}
+          extraButton={followButton}
           showBackButton
         >
           {columnId && <ColumnSettingsContainer columnId={columnId} />}

app/javascript/mastodon/reducers/index.js

@@ -39,6 +39,7 @@ import markers from './markers';
 import picture_in_picture from './picture_in_picture';
 import accounts_map from './accounts_map';
 import history from './history';
+import tags from './tags';
 
 const reducers = {
   announcements,
@@ -81,6 +82,7 @@ const reducers = {
   markers,
   picture_in_picture,
   history,
+  tags,
 };
 
 export default combineReducers(reducers);

app/javascript/mastodon/reducers/tags.js

+import {
+  HASHTAG_FETCH_SUCCESS,
+  HASHTAG_FOLLOW_REQUEST,
+  HASHTAG_FOLLOW_FAIL,
+  HASHTAG_UNFOLLOW_REQUEST,
+  HASHTAG_UNFOLLOW_FAIL,
+} from 'mastodon/actions/tags';
+import { Map as ImmutableMap, fromJS } from 'immutable';
+
+const initialState = ImmutableMap();
+
+export default function tags(state = initialState, action) {
+  switch(action.type) {
+  case HASHTAG_FETCH_SUCCESS:
+    return state.set(action.name, fromJS(action.tag));
+  case HASHTAG_FOLLOW_REQUEST:
+  case HASHTAG_UNFOLLOW_FAIL:
+    return state.setIn([action.name, 'following'], true);
+  case HASHTAG_FOLLOW_FAIL:
+  case HASHTAG_UNFOLLOW_REQUEST:
+    return state.setIn([action.name, 'following'], false);
+  default:
+    return state;
+  }
+};