inpage.js - Documentation

/*global Web3*/
+cleanContextForImports()
+require('web3/dist/web3.min.js')
+const log = require('loglevel')
+const LocalMessageDuplexStream = require('post-message-stream')
+const setupDappAutoReload = require('./lib/auto-reload.js')
+const MetamaskInpageProvider = require('./lib/inpage-provider.js')
+restoreContextAfterImports()
+
+log.setDefaultLevel(process.env.METAMASK_DEBUG ? 'debug' : 'warn')
+
+//
+// setup plugin communication
+//
+
+// setup background connection
+var metamaskStream = new LocalMessageDuplexStream({
+  name: 'inpage',
+  target: 'contentscript',
+})
+
+// compose the inpage provider
+var inpageProvider = new MetamaskInpageProvider(metamaskStream)
+
+//
+// setup web3
+//
+
+if (typeof window.web3 !== 'undefined') {
+  throw new Error(`MetaMask detected another web3.
+     MetaMask will not work reliably with another web3 extension.
+     This usually happens if you have two MetaMasks installed,
+     or MetaMask and another web3 extension. Please remove one
+     and try again.`)
+}
+var web3 = new Web3(inpageProvider)
+web3.setProvider = function () {
+  log.debug('MetaMask - overrode web3.setProvider')
+}
+log.debug('MetaMask - injected web3')
+// export global web3, with usage-detection
+setupDappAutoReload(web3, inpageProvider.publicConfigStore)
+
+// set web3 defaultAccount
+inpageProvider.publicConfigStore.subscribe(function (state) {
+  web3.eth.defaultAccount = state.selectedAddress
+})
+
+// need to make sure we aren't affected by overlapping namespaces
+// and that we dont affect the app with our namespace
+// mostly a fix for web3's BigNumber if AMD's "define" is defined...
+var __define
+
+/**
+ * Caches reference to global define object and deletes it
+ */
+function cleanContextForImports () {
+  __define = global.define
+  try {
+    global.define = undefined
+  } catch (_) {
+    console.warn('MetaMask - global.define could not be deleted.')
+  }
+}
+
+/**
+ * Restores global define object from cached reference
+ */
+function restoreContextAfterImports () {
+  try {
+    global.define = __define
+  } catch (_) {
+    console.warn('MetaMask - global.define could not be overwritten.')
+  }
+}
+