getting stdin to work with examples

.gitignore

@@ -4,4 +4,5 @@ node_modules
 .DS_Store
 bundle.js
 example/streetview.png
+example/markdown.png
 !test/fixtures/node_modules

README.md

@@ -129,8 +129,9 @@ Result:
 
 See the [example/](./example/) folder for more ideas, and the [package.json](./package.json) scripts which run them.
 
+- [example/markdown.js](./example/markdown.js) - Renders a `.md` file with GitHub Flavored Markdown to a PNG image
 - [example/es2015.js](./example/es2015.js) - ES2015 transpiling
-- [example/geolocate.js](./example/geolocate.js) - prints current latitude,longitude to `stdout`
+- [example/geolocate.js](./example/geolocate.js) - prints current `[ latitude, longitude ]` to `stdout`
 - [example/http.js](./example/http.js) - a simple Node.js server that you can throw break points into
 
 ## Features

bin/index.js

@@ -5,9 +5,12 @@ const path = require('path');
 const serverPath = path.join(__dirname, '../server.js');
 
 var args = [ serverPath ].concat(process.argv.slice(2));
-var proc = spawn(electron, args);
+var proc = spawn(electron, args, {
+  stdio: [ process.stdin, 'pipe', 'pipe' ]
+});
 proc.stdout.pipe(process.stdout);
 proc.stderr.pipe(process.stderr);
+
 proc.on('close', function (code) {
   process.exit(code);
 });

example/markdown.js

@@ -0,0 +1,41 @@
+/*
+
+  This demo renders markdown documents to an image.
+
+  - Reads markdown from stdin
+  - Renders it to the document.body with GFM
+  - Shows the browser window and captures the screen
+  - Writes PNG to process.stdout
+
+    npm run markdown
+ */
+
+var marked = require('marked');
+var remote = require('electron').remote;
+
+var css = require.resolve('github-markdown-css/github-markdown.css');
+var cssFile = require('fs').readFileSync(css, 'utf8');
+require('insert-css')(cssFile);
+
+require('get-stdin')()
+  .then(function (src) {
+    capture(src.toString());
+  }, function (err) {
+    console.error(err);
+    process.exit(1);
+  });
+
+function capture (md) {
+  document.body.className = 'markdown-body';
+  document.body.innerHTML = marked(md);
+
+  var browserWindow = remote.getCurrentWindow();
+  browserWindow.show();
+  browserWindow.setContentSize(720, 640);
+  setTimeout(function () {
+    browserWindow.capturePage(function (data) {
+      process.stdout.write(data.toPng());
+      window.close();
+    });
+  }, 500);
+}

lib/preload.js

@@ -8,11 +8,9 @@
   var ipc = electron.ipcRenderer;
   var _process = remote.process;
   var cwd = _process.cwd();
-
-  // setup renderer process to look a bit more like node
-  process.chdir(cwd);
-  process.argv = _process.argv;
-  process.exit = _process.exit.bind(_process);
+
+  // setup process to be more like Node.js
+  hookProcess();
 
   // if we should pipe DevTools console back to terminal
   if (remote.getGlobal('__electronConsoleHook')) {
@@ -27,7 +25,7 @@
   // When there is an uncaught exception in the entry
   // script, we may want to quit the devtool (i.e. for CI)
   // or just print an error in DevTools console (i.e. for dev)
-  var shouldQuit = remote.getGlobal('__shouldElectronQuitOnError');
+  var shouldQuit = remote.getGlobal('__electronQuitOnError');
   if (shouldQuit) {
     window.onerror = function (a, b, c, d, err) {
       fatalError(err);
@@ -63,4 +61,23 @@
   function fatalError (err) {
     ipc.send('error', JSON.stringify(serialize(err)));
   }
+
+  function hookProcess () {
+    // setup renderer process to look a bit more like node
+    process.chdir(cwd);
+    process.argv = _process.argv;
+    process.exit = _process.exit.bind(_process);
+
+    var isTTY = remote.getGlobal('__electronProcessTTY');
+    process.stdin.isTTY = isTTY.stdin;
+    process.stdout.isTTY = isTTY.stdout;
+    process.stderr.isTTY = isTTY.stderr;
+    process.stdin._read = function () {
+      this.push('');
+    };
+
+    ipc.on('stdin', function (event, data) {
+      process.stdin.push(data);
+    });
+  }
 })();

package.json

@@ -32,12 +32,17 @@
     "cross-spawn-async": "^2.1.6",
     "electron-canvas-to-buffer": "^1.0.3",
     "faucet": "0.0.1",
+    "get-stdin": "^5.0.1",
+    "github-markdown-css": "^2.2.0",
     "google-panorama-by-location": "^4.1.1",
     "google-panorama-equirectangular": "^1.2.0",
+    "insert-css": "^0.2.0",
+    "marked": "^0.3.5",
     "tape": "^4.4.0"
   },
   "scripts": {
     "test": "node test/index.js | faucet",
+    "markdown": "./bin/index.js example/markdown.js -hqc < README.md > example/markdown.png",
     "http": "./bin/index.js example/http -w",
     "geolocate": "./bin/index.js example/geolocate.js -qch",
     "es2015": "./bin/index.js example/es2015.js -w -i example/es2015.html",

server.js

@@ -29,15 +29,21 @@ app.commandLine.appendSwitch('disable-http-cache');
 app.commandLine.appendSwitch('v', 0);
 app.commandLine.appendSwitch('vmodule', 'console=0');
 
-global.__shouldElectronQuitOnError = true; // true until app starts
+process.stdin.pause();
+global.__electronQuitOnError = true; // true until app starts
 global.__electronEntryFile = argv._[0];
 global.__electronConsoleHook = argv.console;
 global.__electronBrowserResolve = argv.browserField;
+global.__electronProcessTTY = {
+  stdin: process.stdin.isTTY,
+  stdout: process.stdout.isTTY,
+  stderr: process.stderr.isTTY
+};
 
 var exitWithCode1 = false;
 process.on('uncaughtException', function (err) {
   console.error(err);
-  if (global.__shouldElectronQuitOnError) {
+  if (global.__electronQuitOnError) {
     exitWithCode1 = true;
     app.quit();
   }
@@ -52,6 +58,8 @@ if (argv.index) {
 }
 var htmlData = fs.readFileSync(htmlFile);
 
+// var isTTY = process.stdin.isTTY;
+
 var watcher = null;
 var mainWindow = null;
 app.on('window-all-closed', function () {
@@ -128,25 +136,45 @@ app.on('ready', function () {
   });
 
   webContents.once('did-finish-load', function () {
-    global.__shouldElectronQuitOnError = argv.quit;
-    if (!argv.headless) webContents.openDevTools();
+    global.__electronQuitOnError = argv.quit;
+    if (!argv.headless) {
+      webContents.openDevTools();
+      webContents.once('devtools-opened', sendStdin);
+    } else {
+      // TODO: Find out why this timeout is necessary.
+      // stdin is not triggering if sent immediately
+      setTimeout(function () {
+        sendStdin();
+      }, 500);
+    }
   });
 
   mainWindow.loadURL(mainIndexURL);
   mainWindow.on('closed', function () {
     mainWindow = null;
   });
 
+  function sendStdin () {
+    process.stdin
+      .on('data', function (data) {
+        mainWindow.send('stdin', data);
+      })
+      .on('end', function () {
+        mainWindow.send('stdin', null);
+      })
+      .resume();
+  }
+
   function bail (err) {
     console.error(err.stack ? err.stack : err);
-    if (global.__shouldElectronQuitOnError) {
+    if (global.__electronQuitOnError) {
       exitWithCode1 = true;
       if (mainWindow) mainWindow.close();
     }
   }
 
   function fatal (err) {
-    global.__shouldElectronQuitOnError = true;
+    global.__electronQuitOnError = true;
     bail(err);
   }
 });