gecko-dev/dom/ipc/manifestMessages.js

123 строки
3.7 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.*/
/*
* Manifest obtainer frame script implementation of:
* http://www.w3.org/TR/appmanifest/#obtaining
*
* It searches a top-level browsing context for
* a <link rel=manifest> element. Then fetches
* and processes the linked manifest.
*
* BUG: https://bugzilla.mozilla.org/show_bug.cgi?id=1083410
*/
/*globals content, sendAsyncMessage, addMessageListener, Components*/
'use strict';
const {
utils: Cu,
classes: Cc,
interfaces: Ci
} = Components;
const {
ManifestProcessor
} = Cu.import('resource://gre/modules/WebManifest.jsm', {});
const {
Task: {
spawn, async
}
} = Components.utils.import('resource://gre/modules/Task.jsm', {});
addMessageListener('DOM:ManifestObtainer:Obtain', async(function* (aMsg) {
const response = {
msgId: aMsg.data.msgId,
success: true,
result: undefined
};
try {
response.result = yield fetchManifest();
} catch (err) {
response.success = false;
response.result = cloneError(err);
}
sendAsyncMessage('DOM:ManifestObtainer:Obtain', response);
}));
function cloneError(aError) {
const clone = {
'fileName': String(aError.fileName),
'lineNumber': String(aError.lineNumber),
'columnNumber': String(aError.columnNumber),
'stack': String(aError.stack),
'message': String(aError.message),
'name': String(aError.name)
};
return clone;
}
function fetchManifest() {
return spawn(function* () {
if (!content || content.top !== content) {
let msg = 'Content window must be a top-level browsing context.';
throw new Error(msg);
}
const elem = content.document.querySelector('link[rel~="manifest"]');
if (!elem || !elem.getAttribute('href')) {
let msg = 'No manifest to fetch.';
throw new Error(msg);
}
// Throws on malformed URLs
const manifestURL = new content.URL(elem.href, elem.baseURI);
if (!canLoadManifest(elem)) {
let msg = `Content Security Policy: The page's settings blocked the `;
msg += `loading of a resource at ${elem.href}`;
throw new Error(msg);
}
const reqInit = {
mode: 'cors'
};
if (elem.crossOrigin === 'use-credentials') {
reqInit.credentials = 'include';
}
const req = new content.Request(manifestURL, reqInit);
req.setContentPolicyType(Ci.nsIContentPolicy.TYPE_WEB_MANIFEST);
const response = yield content.fetch(req);
const manifest = yield processResponse(response, content);
return manifest;
});
}
function canLoadManifest(aElem) {
const contentPolicy = Cc['@mozilla.org/layout/content-policy;1']
.getService(Ci.nsIContentPolicy);
const mimeType = aElem.type || 'application/manifest+json';
const elemURI = BrowserUtils.makeURI(
aElem.href, aElem.ownerDocument.characterSet
);
const shouldLoad = contentPolicy.shouldLoad(
Ci.nsIContentPolicy.TYPE_WEB_MANIFEST, elemURI,
aElem.ownerDocument.documentURIObject,
aElem, mimeType, null
);
return shouldLoad === Ci.nsIContentPolicy.ACCEPT;
}
function processResponse(aResp, aContentWindow) {
return spawn(function* () {
const badStatus = aResp.status < 200 || aResp.status >= 300;
if (aResp.type === 'error' || badStatus) {
let msg =
`Fetch error: ${aResp.status} - ${aResp.statusText} at ${aResp.url}`;
throw new Error(msg);
}
const text = yield aResp.text();
const args = {
jsonText: text,
manifestURL: aResp.url,
docURL: aContentWindow.location.href
};
const processor = new ManifestProcessor();
const manifest = processor.process(args);
return Cu.cloneInto(manifest, content);
});
}