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

/**
 *
 * (c) Copyright Ascensio System SIA 2023
 *
 * 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');
let urlModule = require('url');
let urllib = require('urllib');
const xmlParser = require('fast-xml-parser');
const he = require('he');
const siteUrl = configServer.get('siteUrl');  // the path to the editors installation

let cache = null;

async function initWopi(docManager) {
    let absSiteUrl = siteUrl;
    if (absSiteUrl.indexOf('/') === 0) {
        absSiteUrl = docManager.getServerHost() + siteUrl;
    }

    // get the wopi discovery information
    await getDiscoveryInfo(absSiteUrl);
}

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

    if (cache) return cache;

    try {
        actions = await requestDiscovery(siteUrl);
    } catch (e) {
        return actions;
    }

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

    return actions;
}

async function requestDiscovery(siteUrl) {
    return new Promise((resolve, reject) => {
        let actions = [];
        urllib.request(urlModule.parse(siteUrl + configServer.get('wopi.discovery')), {method: 'GET'}, (err, data) => {
            if (data) {
                const 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})
                });
                if (discovery['wopi-discovery']) {
                    for (const app of discovery['wopi-discovery']['net-zone'].app) {
                        if (!Array.isArray(app.action)) {
                            app.action = [app.action];
                        }
                        for (const 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 || ''
                            });
                        }
                    }
                }
            }
            resolve(actions);
        });
    })
}

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

    for (const 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
async function getAction(ext, name) {
    const actions = await getDiscoveryInfo();

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

    return null;
}

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

    for (const 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.initWopi = initWopi;
exports.getDiscoveryInfo = getDiscoveryInfo;
exports.getAction = getAction;
exports.getActions = getActions;
exports.getActionUrl = getActionUrl;
exports.getDefaultAction = getDefaultAction;