Share: support title and url params

app/soapbox/actions/compose.js

@@ -615,3 +615,11 @@ export function changePollSettings(expiresIn, isMultiple) {
     isMultiple,
   };
 }
+
+export function openComposeWithText(text = '') {
+  return (dispatch, getState) => {
+    dispatch(resetCompose());
+    dispatch(openModal('COMPOSE'));
+    dispatch(changeCompose(text));
+  };
+}

app/soapbox/features/share/index.js

@@ -3,14 +3,12 @@ import { connect } from 'react-redux';
 import { Redirect } from 'react-router-dom';
 import PropTypes from 'prop-types';
 import ImmutablePureComponent from 'react-immutable-pure-component';
-import { changeCompose } from '../../actions/compose';
-import { openModal } from '../../actions/modal';
+import { openComposeWithText } from '../../actions/compose';
 
 const mapDispatchToProps = dispatch => ({
 
   onShare: (text) => {
-    dispatch(openModal('COMPOSE'));
-    dispatch(changeCompose(text));
+    dispatch(openComposeWithText(text));
   },
 
 });
@@ -25,8 +23,19 @@ class Share extends ImmutablePureComponent {
   constructor(props) {
     super(props);
 
-    const text = new URLSearchParams(window.location.search).get('text');
-    if (text) this.props.onShare(text);
+    const params = new URLSearchParams(window.location.search);
+
+    const text = [
+      params.get('title'),
+      params.get('text'),
+      params.get('url'),
+    ]
+      .filter(v => v)
+      .join('\n\n');
+
+    if (text) {
+      this.props.onShare(text);
+    }
   }
 
   render() {