node-red-contrib-matrix-chat-jw/src/matrix-send-message.js

const {RelationType} = require("matrix-js-sdk");

module.exports = function(RED) {
    function MatrixSendImage(n) {
        RED.nodes.createNode(this, n);

        var node = this;

        this.name = n.name;
        this.server = RED.nodes.getNode(n.server);
        this.roomId = n.roomId;
        this.messageType = n.messageType;
        this.messageFormat = n.messageFormat;
        this.replaceMessage = n.replaceMessage;
        this.message = n.message;

        // taken from https://github.com/matrix-org/synapse/blob/master/synapse/push/mailer.py
        this.allowedTags = [
            "font", // custom to matrix for IRC-style font coloring
            "del",  // for markdown
            // deliberately no h1/h2 to stop people shouting.
            "h3",
            "h4",
            "h5",
            "h6",
            "blockquote",
            "p",
            "a",
            "ul",
            "ol",
            "nl",
            "li",
            "b",
            "i",
            "u",
            "strong",
            "em",
            "strike",
            "code",
            "hr",
            "br",
            "div",
            "table",
            "thead",
            "caption",
            "tbody",
            "tr",
            "th",
            "td",
            "pre",
        ];

        if (!node.server) {
            node.warn("No configuration node");
            return;
        }

        node.status({ fill: "red", shape: "ring", text: "disconnected" });

        node.server.on("disconnected", function(){
            node.status({ fill: "red", shape: "ring", text: "disconnected" });
        });

        node.server.on("connected", function() {
            node.status({ fill: "green", shape: "ring", text: "connected" });
        });

        node.on("input", function (msg) {
            let msgType = node.messageType,
                msgFormat = node.messageFormat;

            if(msgType === 'msg.type') {
                if(!msg.type) {
                    node.error("msg.type type is set to be passed in via msg.type but was not defined");
                    return;
                }
                msgType = msg.type;
            }

            if(msgFormat === 'msg.format') {
                if(!msg.format) {
                    node.error("Message format is set to be passed in via msg.format but was not defined");
                    return;
                }
                msgFormat = msg.format;
            }

            if (!node.server || !node.server.matrixClient) {
                node.warn("No matrix server selected");
                return;
            }

            if(!node.server.isConnected()) {
                node.error("Matrix server connection is currently closed");
                node.send([null, msg]);
                return;
            }

            msg.topic = node.roomId || msg.topic;
            if(!msg.topic) {
                node.warn("Room must be specified in msg.topic or in configuration");
                return;
            }

            let payload = n.message || msg.payload;
            if(!payload) {
                node.error('msg.payload must be defined or the message configured on the node.');
                return;
            }

            let content = {
                msgtype: msgType,
                body: payload.toString()
            };

            if(msgFormat === 'html') {
                content.format = "org.matrix.custom.html";
                content.formatted_body =
                    (typeof msg.formatted_payload !== 'undefined' && msg.formatted_payload)
                        ? msg.formatted_payload.toString()
                        : payload.toString();
            }

            if((node.replaceMessage || msg.replace) && msg.eventId) {
                content['m.new_content'] = {
                    msgtype: content.msgtype,
                    body: content.body
                };
                if('format' in content) {
                    content['m.new_content']['format'] = content['format'];
                }
                if('formatted_body' in content) {
                    content['m.new_content']['formatted_body'] = content['formatted_body'];
                }

                content['m.relates_to'] = {
                    rel_type: RelationType.Replace,
                    event_id: msg.eventId
                };
                content['body'] = ' * ' + content['body'];
            }

            node.server.matrixClient.sendMessage(msg.topic, content)
                .then(function(e) {
                    node.log("Message sent: " + payload);
                    msg.eventId = e.event_id;
                    node.send([msg, null]);
                })
                .catch(function(e){
                    node.warn("Error sending message " + e);
                    msg.error = e;
                    node.send([null, msg]);
                });
        });
    }
    RED.nodes.registerType("matrix-send-message", MatrixSendImage);
}