WIP filtered timelines

lib/filter-component.js

@@ -0,0 +1,119 @@
+/*
+Copyright 2016 OpenMarket Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+"use strict";
+/**
+ * @module filter-component
+ */
+
+function _matches_wildcard(actual_value, filter_value) {
+    if (filter_value.endsWith("*")) {
+        type_prefix = filter_value.slice(0, -1);
+        return actual_value.substr(0, type_prefix.length) === type_prefix;
+    }
+    else {
+        return actual_value === filter_value;
+    }
+}
+
+/**
+ * A FilterComponent is a section of a Filter definition which defines the
+ * types, rooms, senders filters etc to be applied to a particular type of resource.
+ *
+ * This is all ported from synapse's Filter object.
+ */
+FilterComponent = function(filter_json) {
+    this.filter_json = filter_json;
+
+    this.types = filter_json.types || null;
+    this.not_types = filter_json.not_types || [];
+
+    self.rooms = filter_json.rooms || null;
+    self.not_rooms = filter_json.not_rooms || [];
+
+    self.senders = filter_json.senders || null;
+    self.not_senders = filter_json.not_senders || [];
+
+    self.contains_url = filter_json.contains_url || null;
+};
+
+/**
+ * Checks with the filter component matches the given event
+ */
+FilterComponent.prototype.check = function(event) {
+    var sender = event.sender;
+    if (!sender) {
+        // Presence events have their 'sender' in content.user_id
+        if (event.content) {
+            sender = event.content.user_id;
+        }
+    }
+
+    return this.checkFields(
+        event.room_id,
+        sender,
+        event.type,
+        event.content ? event.content.url !== undefined : false,
+    );
+};
+
+/**
+ * Checks whether the filter matches the given event fields.
+ */
+FilterComponent.prototype.checkFields =
+    function(room_id, sender, event_type, contains_url) {
+        var literal_keys = {
+            "rooms": function(v) { return room_id === v; },
+            "senders": function(v) { return sender === v; },
+            "types": function(v) { return _matches_wildcard(event_type, v); },
+        };
+
+        Object.keys(literal_keys).forEach(function(name) {
+            var match_func = literal_keys[name];
+            var not_name = "not_" + name;
+            var disallowed_values = this[not_name];
+            if (disallowed_values.map(match_func)) {
+                return false;
+            }
+
+            var allowed_values = this[name];
+            if (allowed_values) {
+                if (!allowed_values.map(match_func)) {
+                    return false;
+                }
+            }
+        });
+
+        contains_url_filter = this.filter_json.contains_url;
+        if (contains_url_filter !== undefined) {
+            if (contains_url_filter !== contains_url) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+};
+
+FilterComponent.prototype.filter = function(events) {
+    return events.filter(this.check);
+};
+
+FilterComponent.prototype.limit = function() {
+    return this.filter_json.limit !== undefined ? this.filter_json.limit : 10;
+};
+
+/** The FilterComponent class */
+module.exports = FilterComponent;