electron/lib/browser/chrome-extension.js
2016-05-26 19:57:10 +09:00

182 lines
5.5 KiB
JavaScript

const {app, protocol, webContents, BrowserWindow} = require('electron')
const fs = require('fs')
const path = require('path')
const url = require('url')
// TODO(zcbenz): Remove this when we have Object.values().
const objectValues = function (object) {
return Object.keys(object).map(function (key) { return object[key] })
}
// Mapping between hostname and file path.
let hostPathMap = {}
let hostPathMapNextKey = 0
const generateHostForPath = function (path) {
let key = `extension-${++hostPathMapNextKey}`
hostPathMap[key] = path
return key
}
const getPathForHost = function (host) {
return hostPathMap[host]
}
// Cache manifests.
let manifestMap = {}
const getManifestFromPath = function (srcDirectory) {
let manifest = JSON.parse(fs.readFileSync(path.join(srcDirectory, 'manifest.json')))
if (!manifestMap[manifest.name]) {
const hostname = generateHostForPath(srcDirectory)
manifestMap[manifest.name] = manifest
Object.assign(manifest, {
srcDirectory: srcDirectory,
hostname: hostname,
// We can not use 'file://' directly because all resources in the extension
// will be treated as relative to the root in Chrome.
startPage: url.format({
protocol: 'chrome-extension',
slashes: true,
hostname: hostname,
pathname: manifest.devtools_page
})
})
return manifest
}
}
// Manage the background pages.
let backgroundPages = {}
const startBackgroundPages = function (manifest) {
if (backgroundPages[manifest.hostname] || !manifest.background) return
const scripts = manifest.background.scripts.map((name) => {
return `<script src="${name}"></script>`
}).join('')
const html = new Buffer(`<html><body>${scripts}</body></html>`)
const contents = webContents.create({})
backgroundPages[manifest.hostname] = { html: html, contents: contents }
contents.loadURL(url.format({
protocol: 'chrome-extension',
slashes: true,
hostname: manifest.hostname,
pathname: '_generated_background_page.html'
}))
}
// Transfer the |manifest| to a format that can be recognized by the
// |DevToolsAPI.addExtensions|.
const manifestToExtensionInfo = function (manifest) {
return {
startPage: manifest.startPage,
srcDirectory: manifest.srcDirectory,
name: manifest.name,
exposeExperimentalAPIs: true
}
}
// Load the extensions for the window.
const loadDevToolsExtensions = function (win, manifests) {
if (!win.devToolsWebContents) return
for (let manifest of manifests) {
startBackgroundPages(manifest)
}
const extensionInfoArray = manifests.map(manifestToExtensionInfo)
win.devToolsWebContents.executeJavaScript(`DevToolsAPI.addExtensions(${JSON.stringify(extensionInfoArray)})`)
}
// The persistent path of "DevTools Extensions" preference file.
let loadedExtensionsPath = null
app.on('will-quit', function () {
try {
let loadedExtensions = objectValues(manifestMap).map(function (manifest) {
return manifest.srcDirectory
})
if (loadedExtensions.length > 0) {
try {
fs.mkdirSync(path.dirname(loadedExtensionsPath))
} catch (error) {
// Ignore error
}
fs.writeFileSync(loadedExtensionsPath, JSON.stringify(loadedExtensions))
} else {
fs.unlinkSync(loadedExtensionsPath)
}
} catch (error) {
// Ignore error
}
})
// We can not use protocol or BrowserWindow until app is ready.
app.once('ready', function () {
// Load persisted extensions.
loadedExtensionsPath = path.join(app.getPath('userData'), 'DevTools Extensions')
try {
let loadedExtensions = JSON.parse(fs.readFileSync(loadedExtensionsPath))
if (Array.isArray(loadedExtensions)) {
// Preheat the manifest cache.
for (let srcDirectory of loadedExtensions) {
getManifestFromPath(srcDirectory)
}
}
} catch (error) {
// Ignore error
}
// The chrome-extension: can map a extension URL request to real file path.
const chromeExtensionHandler = function (request, callback) {
let parsed = url.parse(request.url)
if (!parsed.hostname || !parsed.path) return callback()
if (!/extension-\d+/.test(parsed.hostname)) return callback()
let directory = getPathForHost(parsed.hostname)
if (!directory) return callback()
if (parsed.path === '/_generated_background_page.html' &&
backgroundPages[parsed.hostname]) {
return callback({
mimeType: 'text/html',
data: backgroundPages[parsed.hostname].html
})
}
fs.readFile(path.join(directory, parsed.path), function (err, content) {
if (err)
callback(-6) // FILE_NOT_FOUND
else
return callback({mimeType: 'text/html', data: content})
})
}
protocol.registerBufferProtocol('chrome-extension', chromeExtensionHandler, function (error) {
if (error) {
console.error(`Unable to register chrome-extension protocol: ${error}`)
}
})
BrowserWindow.addDevToolsExtension = function (srcDirectory) {
const manifest = getManifestFromPath(srcDirectory)
if (manifest) {
for (let win of BrowserWindow.getAllWindows()) {
loadDevToolsExtensions(win, [manifest])
}
return manifest.name
}
}
BrowserWindow.removeDevToolsExtension = function (name) {
delete manifestMap[name]
}
// Load persisted extensions when devtools is opened.
let init = BrowserWindow.prototype._init
BrowserWindow.prototype._init = function () {
init.call(this)
this.webContents.on('devtools-opened', () => {
loadDevToolsExtensions(this, objectValues(manifestMap))
})
}
})