document-server-integration/web/documentserver-example/nodejs/helpers/wopi/utils.js

/**
 *
 * (c) Copyright Ascensio System SIA 2021
 *
 * 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.
 *
 */

const config = require("config");
const configServer = config.get("server");
var urlModule = require("url");
var urllib = require("urllib");
const xmlParser = require("fast-xml-parser");
const he = require("he");

var cache = null;

// get the wopi discovery information
function getDiscoveryInfo(siteUrl) {
    let actions = [];

    if (cache) return cache;

    try {
        urllib.request(urlModule.parse(siteUrl + configServer.get("wopi.discovery")), {method: "GET"}, (err, data) => {
            if (data) {
                let discovery = xmlParser.parse(data.toString(), {  // create the discovery XML file with the parameters from the response
                    attributeNamePrefix: "",
                    ignoreAttributes: false,
                    parseAttributeValue: true,
                    attrValueProcessor: (val, attrName) => he.decode(val, {isAttributeValue: true})
                });
                for (let app of discovery["wopi-discovery"]["net-zone"].app) {
                    if (!Array.isArray(app.action)) {
                        app.action = [app.action];
                    }
                    for (let action of app.action) {
                        actions.push({  // write all the parameters to the actions element
                            app: app.name,
                            favIconUrl: app.favIconUrl,
                            checkLicense: app.checkLicense == 'true',
                            name: action.name,
                            ext: action.ext || "",
                            progid: action.progid || "",
                            isDefault: action.default ? true : false,
                            urlsrc: action.urlsrc,
                            requires: action.requires || ""
                        });
                    }
                }
            }
        });
    } catch (e) {
        return actions;
    }

    cache = actions;
    setTimeout(() => cache = null, 1000 * 60 * 60); // 1 hour

    return actions;
}

// get actions of the specified extension
function getActions(ext) {
    let actions = getDiscoveryInfo();  // get the wopi discovery information
    let filtered = [];

    for (let action of actions) {  // and filter it by the specified extention
        if (action.ext == ext) {
            filtered.push(action);
        }
    }

    return filtered;
}

// get an action for the specified extension and name
function getAction(ext, name) {
    let actions = getDiscoveryInfo();

    for (let action of actions) {
        if (action.ext == ext && action.name == name) {
            return action;
        }
    }

    return null;
}

// get the default action for the specified extension
function getDefaultAction(ext) {
    let actions = getDiscoveryInfo();

    for (let action of actions) {
        if (action.ext == ext && action.isDefault) {
            return action;
        }
    }

    return null;
}

// get the action url
function getActionUrl(host, userAddress, action, filename) {
    return action.urlsrc.replace(/<.*&>/g, "") + "WOPISrc=" + host + "/wopi/files/" + filename + "@" + userAddress;
}

exports.getDiscoveryInfo = getDiscoveryInfo;
exports.getAction = getAction;
exports.getActions = getActions;
exports.getActionUrl = getActionUrl;
exports.getDefaultAction = getDefaultAction;