2021-02-02 18:56:57 +01:00

513 lines
19 KiB
TypeScript

// (C) Copyright 2015 Moodle Pty 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.
import { Injectable } from '@angular/core';
import { WKUserScriptWindow } from 'cordova-plugin-wkuserscript';
import { WKWebViewCookiesWindow } from 'cordova-plugin-wkwebview-cookies';
import { CoreApp } from '@services/app';
import { CoreFile } from '@services/file';
import { CoreFileHelper } from '@services/file-helper';
import { CoreSites } from '@services/sites';
import { CoreDomUtils } from '@services/utils/dom';
import { CoreTextUtils } from '@services/utils/text';
import { CoreUrlUtils } from '@services/utils/url';
import { CoreUtils } from '@services/utils/utils';
import { makeSingleton, Network, Platform, NgZone } from '@singletons';
import { CoreLogger } from '@singletons/logger';
import { CoreUrl } from '@singletons/url';
import { CoreWindow } from '@singletons/window';
/**
* Possible types of frame elements.
*/
type CoreFrameElement = (HTMLIFrameElement | HTMLFrameElement | HTMLObjectElement | HTMLEmbedElement) & {
window?: Window;
getWindow?(): Window;
};
/*
* "Utils" service with helper functions for iframes, embed and similar.
*/
@Injectable({ providedIn: 'root' })
export class CoreIframeUtilsProvider {
static readonly FRAME_TAGS = ['iframe', 'frame', 'object', 'embed'];
protected logger: CoreLogger;
constructor() {
this.logger = CoreLogger.getInstance('CoreUtilsProvider');
if (CoreApp.instance.isIOS() && 'WKUserScript' in window) {
// eslint-disable-next-line promise/catch-or-return
Platform.instance.ready().then(() => this.injectiOSScripts(window));
}
}
/**
* Check if a frame uses an online URL but the app is offline. If it does, the iframe is hidden and a warning is shown.
*
* @param element The frame to check (iframe, embed, ...).
* @param isSubframe Whether it's a frame inside another frame.
* @return True if frame is online and the app is offline, false otherwise.
*/
checkOnlineFrameInOffline(element: CoreFrameElement, isSubframe?: boolean): boolean {
const src = 'src' in element ? element.src : element.data;
if (src && src != 'about:blank' && !CoreUrlUtils.instance.isLocalFileUrl(src) && !CoreApp.instance.isOnline()) {
if (element.classList.contains('core-iframe-offline-disabled')) {
// Iframe already hidden, stop.
return true;
}
// The frame has an online URL but the app is offline. Show a warning, or a link if the URL can be opened in the app.
const div = document.createElement('div');
div.setAttribute('text-center', '');
div.setAttribute('padding', '');
div.classList.add('core-iframe-offline-warning');
// @todo Handle link
// Add a class to specify that the iframe is hidden.
element.classList.add('core-iframe-offline-disabled');
if (isSubframe) {
// We cannot apply CSS styles in subframes, just hide the iframe.
element.style.display = 'none';
}
// If the network changes, check it again.
const subscription = Network.instance.onConnect().subscribe(() => {
// Execute the callback in the Angular zone, so change detection doesn't stop working.
NgZone.instance.run(() => {
if (!this.checkOnlineFrameInOffline(element, isSubframe)) {
// Now the app is online, no need to check connection again.
subscription.unsubscribe();
}
});
});
return true;
} else if (element.classList.contains('core-iframe-offline-disabled')) {
// Reload the frame.
if ('src' in element) {
// eslint-disable-next-line no-self-assign
element.src = element.src;
} else {
// eslint-disable-next-line no-self-assign
element.data = element.data;
}
// Remove the warning and show the iframe
CoreDomUtils.instance.removeElement(element.parentElement!, 'div.core-iframe-offline-warning');
element.classList.remove('core-iframe-offline-disabled');
if (isSubframe) {
element.style.display = '';
}
}
return false;
}
/**
* Given an element, return the content window and document.
* Please notice that the element should be an iframe, embed or similar.
*
* @param element Element to treat (iframe, embed, ...).
* @return Window and Document.
*/
getContentWindowAndDocument(element: CoreFrameElement): { window: Window | null; document: Document | null } {
let contentWindow: Window | null = 'contentWindow' in element ? element.contentWindow : null;
let contentDocument: Document | null = null;
try {
contentDocument = 'contentDocument' in element && element.contentDocument
? element.contentDocument
: contentWindow && contentWindow.document;
} catch (ex) {
// Ignore errors.
}
if (!contentWindow && contentDocument) {
// It's probably an <object>. Try to get the window.
contentWindow = contentDocument.defaultView;
}
if (!contentWindow && 'getSVGDocument' in element) {
// It's probably an <embed>. Try to get the window and the document.
try {
contentDocument = element.getSVGDocument();
} catch (ex) {
// Ignore errors.
}
if (contentDocument && contentDocument.defaultView) {
contentWindow = contentDocument.defaultView;
} else if (element.window) {
contentWindow = element.window;
} else if (element.getWindow) {
contentWindow = element.getWindow();
}
}
return { window: contentWindow, document: contentDocument };
}
/**
* Handle some iframe messages.
*
* @param event Message event.
*/
handleIframeMessage(event: MessageEvent): void {
if (!event.data || event.data.environment != 'moodleapp' || event.data.context != 'iframe') {
return;
}
switch (event.data.action) {
case 'window_open':
this.windowOpen(event.data.url, event.data.name);
break;
case 'link_clicked':
this.linkClicked(event.data.link);
break;
}
}
/**
* Redefine the open method in the contentWindow of an element and the sub frames.
* Please notice that the element should be an iframe, embed or similar.
*
* @param element Element to treat (iframe, embed, ...).
* @param contentWindow The window of the element contents.
* @param contentDocument The document of the element contents.
*/
redefineWindowOpen(
element: CoreFrameElement,
contentWindow: Window,
contentDocument: Document,
): void {
if (contentWindow) {
// Intercept window.open.
contentWindow.open = (url: string, name: string) => {
this.windowOpen(url, name, element);
// eslint-disable-next-line @typescript-eslint/no-explicit-any
return null as any;
};
}
if (contentDocument) {
// Search sub frames.
CoreIframeUtilsProvider.FRAME_TAGS.forEach((tag) => {
const elements = Array.from(contentDocument.querySelectorAll(tag));
elements.forEach((subElement: CoreFrameElement) => {
this.treatFrame(subElement, true);
});
});
}
}
/**
* Intercept window.open in a frame and its subframes, shows an error modal instead.
* Search links (<a>) and open them in browser or InAppBrowser if needed.
*
* @param element Element to treat (iframe, embed, ...).
* @param isSubframe Whether it's a frame inside another frame.
*/
treatFrame(element: CoreFrameElement, isSubframe?: boolean): void {
if (!element) {
return;
}
const treatElement = (sendResizeEvent: boolean = false) => {
this.checkOnlineFrameInOffline(element, isSubframe);
const { window, document } = this.getContentWindowAndDocument(element);
// Redefine window.open in this element and sub frames, it might have been loaded already.
if (window && document) {
this.redefineWindowOpen(element, window, document);
}
// Treat links.
if (document) {
this.treatFrameLinks(element, document);
}
// Send a resize events to the iframe so it calculates the right size if needed.
if (window && sendResizeEvent) {
setTimeout(() => window.dispatchEvent(new Event('resize')), 1000);
}
};
treatElement();
// Element loaded, redefine window.open and treat links again.
element.addEventListener('load', () => treatElement(true));
}
/**
* Search links (<a>) in a frame and open them in browser or InAppBrowser if needed.
* Only links that haven't been treated by the frame's Javascript will be treated.
*
* @param element Element to treat (iframe, embed, ...).
* @param contentDocument The document of the element contents.
*/
treatFrameLinks(element: CoreFrameElement, contentDocument: Document): void {
if (!contentDocument) {
return;
}
contentDocument.addEventListener('click', (event) => {
if (event.defaultPrevented) {
// Event already prevented by some other code.
return;
}
// Find the link being clicked.
let el: Element | null = event.target as Element;
while (el && el.tagName !== 'A') {
el = el.parentElement;
}
const link = <CoreIframeHTMLAnchorElement> el;
if (!link || link.treated) {
return;
}
// Add click listener to the link, this way if the iframe has added a listener to the link it will be executed first.
link.treated = true;
link.addEventListener('click', this.linkClicked.bind(this, link, element));
}, {
capture: true, // Use capture to fix this listener not called if the element clicked is too deep in the DOM.
});
}
/**
* Handle a window.open called by a frame.
*
* @param url URL passed to window.open.
* @param name Name passed to window.open.
* @param element HTML element of the frame.
* @return Promise resolved when done.
*/
protected async windowOpen(url: string, name: string, element?: CoreFrameElement): Promise<void> {
const scheme = CoreUrlUtils.instance.getUrlScheme(url);
if (!scheme) {
// It's a relative URL, use the frame src to create the full URL.
const src = element
? ('src' in element ? element.src : element.data)
: null;
if (src) {
const dirAndFile = CoreFile.instance.getFileAndDirectoryFromPath(src);
if (dirAndFile.directory) {
url = CoreTextUtils.instance.concatenatePaths(dirAndFile.directory, url);
} else {
this.logger.warn('Cannot get iframe dir path to open relative url', url, element);
return;
}
} else {
this.logger.warn('Cannot get iframe src to open relative url', url, element);
return;
}
}
if (name == '_self') {
// Link should be loaded in the same frame.
if (!element) {
this.logger.warn('Cannot load URL in iframe because the element was not supplied', url);
return;
}
if (element.tagName.toLowerCase() == 'object') {
element.setAttribute('data', url);
} else {
element.setAttribute('src', url);
}
} else if (CoreUrlUtils.instance.isLocalFileUrl(url)) {
// It's a local file.
const filename = url.substr(url.lastIndexOf('/') + 1);
if (!CoreFileHelper.instance.isOpenableInApp({ filename })) {
try {
await CoreFileHelper.instance.showConfirmOpenUnsupportedFile();
} catch (error) {
return; // Cancelled, stop.
}
}
try {
await CoreUtils.instance.openFile(url);
} catch (error) {
CoreDomUtils.instance.showErrorModal(error);
}
} else {
// It's an external link, check if it can be opened in the app.
await CoreWindow.open(url, name);
}
}
/**
* A link inside a frame was clicked.
*
* @param link Data of the link clicked.
* @param element Frame element.
* @param event Click event.
* @return Promise resolved when done.
*/
protected async linkClicked(
link: {href: string; target?: string},
element?: HTMLFrameElement | HTMLObjectElement,
event?: Event,
): Promise<void> {
if (event && event.defaultPrevented) {
// Event already prevented by some other code.
return;
}
const urlParts = CoreUrl.parse(link.href);
if (!link.href || !urlParts || (urlParts.protocol && urlParts.protocol == 'javascript')) {
// Links with no URL and Javascript links are ignored.
return;
}
if (urlParts.protocol && !CoreUrlUtils.instance.isLocalFileUrlScheme(urlParts.protocol, urlParts.domain || '')) {
// Scheme suggests it's an external resource.
event && event.preventDefault();
const frameSrc = element && ((<HTMLFrameElement> element).src || (<HTMLObjectElement> element).data);
// If the frame is not local, check the target to identify how to treat the link.
if (
element &&
frameSrc &&
!CoreUrlUtils.instance.isLocalFileUrl(frameSrc) &&
(!link.target || link.target == '_self')
) {
// Load the link inside the frame itself.
if (element.tagName.toLowerCase() == 'object') {
element.setAttribute('data', link.href);
} else {
element.setAttribute('src', link.href);
}
return;
}
// The frame is local or the link needs to be opened in a new window. Open in browser.
if (!CoreSites.instance.isLoggedIn()) {
CoreUtils.instance.openInBrowser(link.href);
} else {
await CoreSites.instance.getCurrentSite()!.openInBrowserWithAutoLoginIfSameSite(link.href);
}
} else if (link.target == '_parent' || link.target == '_top' || link.target == '_blank') {
// Opening links with _parent, _top or _blank can break the app. We'll open it in InAppBrowser.
event && event.preventDefault();
const filename = link.href.substr(link.href.lastIndexOf('/') + 1);
if (!CoreFileHelper.instance.isOpenableInApp({ filename })) {
try {
await CoreFileHelper.instance.showConfirmOpenUnsupportedFile();
} catch (error) {
return; // Cancelled, stop.
}
}
try {
await CoreUtils.instance.openFile(link.href);
} catch (error) {
CoreDomUtils.instance.showErrorModal(error);
}
} else if (CoreApp.instance.isIOS() && (!link.target || link.target == '_self') && element) {
// In cordova ios 4.1.0 links inside iframes stopped working. We'll manually treat them.
event && event.preventDefault();
if (element.tagName.toLowerCase() == 'object') {
element.setAttribute('data', link.href);
} else {
element.setAttribute('src', link.href);
}
}
}
/**
* Inject code to the iframes because we cannot access the online ones.
*
* @param userScriptWindow Window.
*/
private injectiOSScripts(userScriptWindow: WKUserScriptWindow) {
const wwwPath = CoreFile.instance.getWWWAbsolutePath();
const linksPath = CoreTextUtils.instance.concatenatePaths(wwwPath, 'assets/js/iframe-treat-links.js');
const recaptchaPath = CoreTextUtils.instance.concatenatePaths(wwwPath, 'assets/js/iframe-recaptcha.js');
userScriptWindow.WKUserScript?.addScript({ id: 'CoreIframeUtilsLinksScript', file: linksPath });
userScriptWindow.WKUserScript?.addScript({
id: 'CoreIframeUtilsRecaptchaScript',
file: recaptchaPath,
injectionTime: userScriptWindow.WKUserScript?.InjectionTime.END,
});
// Handle post messages received by iframes.
window.addEventListener('message', this.handleIframeMessage.bind(this));
}
/**
* Fix cookies for an iframe URL.
*
* @param url URL of the iframe.
* @return Promise resolved when done.
*/
async fixIframeCookies(url: string): Promise<void> {
if (!CoreApp.instance.isIOS() || !url || CoreUrlUtils.instance.isLocalFileUrl(url)) {
// No need to fix cookies.
return;
}
// Save a "fake" cookie for the iframe's domain to fix a bug in WKWebView.
try {
const win = <WKWebViewCookiesWindow> window;
const urlParts = CoreUrl.parse(url);
if (urlParts?.domain && win.WKWebViewCookies) {
await win.WKWebViewCookies.setCookie({
name: 'MoodleAppCookieForWKWebView',
value: '1',
domain: urlParts.domain,
});
}
} catch (err) {
// Ignore errors.
this.logger.error('Error setting cookie', err);
}
}
}
export class CoreIframeUtils extends makeSingleton(CoreIframeUtilsProvider) {}
/**
* Subtype of HTMLAnchorElement, with some calculated data.
*/
type CoreIframeHTMLAnchorElement = HTMLAnchorElement & {
treated?: boolean; // Whether the element has been treated already.
};