ampproject · mkhatib · Jun 6, 2016 · May 28, 2016 · Jun 2, 2016 · Jun 2, 2016
diff --git a/build-system/server.js b/build-system/server.js
@@ -24,6 +24,7 @@ var bodyParser = require('body-parser');
 var clr = require('connect-livereload');
 var finalhandler = require('finalhandler');
 var fs = BBPromise.promisifyAll(require('fs'));
+var formidable = require('formidable');
 var jsdom = require('jsdom');
 var path = require('path');
 var request = require('request');
@@ -69,6 +70,25 @@ app.use('/api/echo/post', function(req, res) {
   res.end(JSON.stringify(req.body, null, 2));
 });
 
+app.use('/form/echo-html/post', function(req, res) {
+  var form = new formidable.IncomingForm();
+  form.parse(req, function(err, fields) {
+    res.setHeader('Content-Type', 'text/html');
+    if (fields['email'] == 'already@subscribed.com') {
+      res.statusCode = 500;
+      res.end(`
+        <h1 style="color:red;">Sorry ${fields['name']}!</h1>
+        <p>The email ${fields['email']} is already subscribed!</p>
+      `);
+    } else {
+      res.end(`
+      <h1>Thanks ${fields['name']}!</h1>
+        <p>Please make sure to confirm your email ${fields['email']}</p>
+      `);
+    }
+  });
+});
+
 // Fetches an AMP document from the AMP proxy and replaces JS
 // URLs, so that they point to localhost.
 function proxyToAmpProxy(req, res, minify) {

diff --git a/build-system/tasks/presubmit-checks.js b/build-system/tasks/presubmit-checks.js
@@ -289,6 +289,8 @@ var forbiddenTerms = {
       'validator/tokenize-css.js',
       'validator/validator-full.js',
       'validator/validator.js',
+      // exports.startsWith occurs in babel generated code.
+      'dist.3p/current/integration.js',
     ]
   },
   '\\.endsWith': {

diff --git a/examples/forms.amp.html b/examples/forms.amp.html
@@ -0,0 +1,56 @@
+<!doctype html>
+<html ⚡>
+<head>
+    <meta charset="utf-8">
+    <title>Forms Examples in AMP</title>
+    <link rel="canonical" href="amps.html" >
+    <meta name="viewport" content="width=device-width,minimum-scale=1,initial-scale=1">
+    <style amp-boilerplate>body{-webkit-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-moz-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-ms-animation:-amp-start 8s steps(1,end) 0s 1 normal both;animation:-amp-start 8s steps(1,end) 0s 1 normal both}@-webkit-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-moz-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-ms-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-o-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}</style><noscript><style amp-boilerplate>body{-webkit-animation:none;-moz-animation:none;-ms-animation:none;animation:none}</style></noscript>
+    <script async src="https://cdn.ampproject.org/v0.js"></script>
+    <style amp-custom>
+        input:invalid {
+            background-color: #dc4e41;
+        }
+
+        form .valid-message,
+        form .invalid-message
+         {
+            display: none;
+        }
+
+        form:invalid .invalid-message {
+            display: block;
+            color: #dc4e41;
+        }
+
+        form:valid .valid-message {
+            display: block;
+            color: #4CAF50;
+        }
+    </style>
+</head>
+<body>
+<h2>Subscribe to our weekly Newsletter</h2>
+
+<form method="post" action="http://localhost:8000/form/echo-html/post" target="_blank">
+    <fieldset>
+        <label>
+            <span>Your name</span>
+            <input type="text" name="name" required>
+        </label>
+        <label>
+            <span>Your email</span>
+            <input type="email" name="email" required>
+        </label>
+        <input type="submit" value="Subscribe">
+    </fieldset>
+
+    <div class="invalid-message">
+        There are some input that needs fixing. Please fix them.
+    </div>
+    <div class="valid-message">
+        Everything looks good, you can submit now!
+    </div>
+</form>
+</body>
+</html>
diff --git a/gulpfile.js b/gulpfile.js
@@ -325,6 +325,7 @@ function buildExamples(watch) {
   buildExample('metadata-examples/video-microdata.amp.html');
   buildExample('everything.amp.html');
   buildExample('font.amp.html');
+  buildExample('forms.amp.html');
   buildExample('facebook.amp.html');
   buildExample('instagram.amp.html');
   buildExample('jwplayer.amp.html');

diff --git a/package.json b/package.json
@@ -42,6 +42,7 @@
     "eslint": "1.10.3",
     "eslint-plugin-google-camelcase": "0.0.2",
     "finalhandler": "0.4.0",
+    "formidable": "1.0.17",
     "fs-extra": "0.27.0",
     "gulp": "3.9.1",
     "gulp-closure-compiler": "0.4.0",

diff --git a/src/amp.js b/src/amp.js
@@ -20,6 +20,7 @@ import {installPullToRefreshBlocker} from './pull-to-refresh';
 import {templatesFor} from './template';
 import {installCoreServices} from './amp-core-service';
 import {installGlobalClickListener} from './document-click';
+import {installGlobalSubmitListener} from './document-submit';
 import {installImg} from '../builtins/amp-img';
 import {installVideo} from '../builtins/amp-video';
 import {installPixel} from '../builtins/amp-pixel';
@@ -30,6 +31,7 @@ import {adopt} from './runtime';
 import {cssText} from '../build/css';
 import {maybeValidate} from './validator-integration';
 import {maybeTrackImpression} from './impression';
+import {isExperimentOn} from './experiments';
 
 // We must under all circumstances call makeBodyVisible.
 // It is much better to have AMP tags not rendered than having
@@ -57,6 +59,9 @@ try {
 
       installPullToRefreshBlocker(window);
       installGlobalClickListener(window);
+      if (isExperimentOn(window, 'form-submit')) {
+        installGlobalSubmitListener(window);
+      }
 
       maybeValidate(window);
       makeBodyVisible(document, /* waitForExtensions */ true);

diff --git a/src/document-submit.js b/src/document-submit.js
@@ -0,0 +1,68 @@
+/**
+ * Copyright 2016 The AMP HTML Authors. All Rights Reserved.
+ *
+ * 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 {startsWith} from '../src/string';
+import {user} from '../src/log';
+import {assertHttpsUrl} from '../src/url';
+
+
+/**
+ * @param {!Window} window
+ */
+export function installGlobalSubmitListener(window) {
+  window.document.documentElement.addEventListener(
+      'submit', onDocumentFormSubmit_, true);
+}
+
+
+/**
+ * Intercept any submit on the current document and prevent invalid submits from
+ * going through.
+ *
+ * @param {!Event} e
+ */
+export function onDocumentFormSubmit_(e) {
+  if (e.defaultPrevented) {
+    return;
+  }
+
+  const form = e.target;
+  if (!form || form.tagName != 'FORM') {
+    return;
+  }
+
+  const action = form.getAttribute('action');
+  user.assert(action, 'form action attribute is required: %s', form);
+  assertHttpsUrl(action, form, 'action');
+  user.assert(!startsWith(action, 'https://cdn.ampproject.org'),
+      'form action should not be on cdn.ampproject.org: %s', form);
+
+  const target = form.getAttribute('target');
+  user.assert(target, 'form target attribute is required: %s', form);
+  user.assert(target == '_blank' || target == '_top',
+      'form target=%s is invalid can only be _blank or _top: %s', target, form);
+
+  // Safari does not trigger validation check on submission, hence we
+  // trigger it manually. In other browsers this would never execute since
+  // the submit event wouldn't be fired if the form is invalid.
+  // TODO: This doesn't display the validation error messages. Safari makes them
+  // available per input.validity object. We need to figure out a way of
+  // displaying these.
+  if (form.checkValidity && !form.checkValidity()) {
+    e.preventDefault();
+    return;
+  }
+}
diff --git a/src/string.js b/src/string.js
@@ -39,6 +39,19 @@ export function endsWith(string, suffix) {
   return string.indexOf(suffix, index) == index;
 }
 
+/**
+ * Polyfill for String.prototype. startsWith.
+ * @param {string} string
+ * @param {string} prefix
+ * @return {boolean}
+ */
+export function startsWith(string, prefix) {
+  if (prefix.length > string.length) {
+    return false;
+  }
+  return string.indexOf(prefix) == 0;
+}
+
 /**
  * Expands placeholders in a given template string with values.
  *

diff --git a/src/url.js b/src/url.js
@@ -123,18 +123,21 @@ export function addParamsToUrl(url, params) {
  *
  * @param {?string|undefined} urlString
  * @param {!Element|string} elementContext Element where the url was found.
+ * @param {string=} sourceName Used for error messages.
  * @return {string}
  */
-export function assertHttpsUrl(urlString, elementContext) {
-  user.assert(urlString != null, '%s source must be available', elementContext);
+export function assertHttpsUrl(
+    urlString, elementContext, sourceName = 'source') {
+  user.assert(urlString != null, '%s %s must be available',
+      elementContext, sourceName);
   const url = parseUrl(urlString);
   user.assert(
       url.protocol == 'https:' || /^(\/\/)/.test(urlString) ||
       url.hostname == 'localhost' || endsWith(url.hostname, '.localhost'),
-      '%s source must start with ' +
+      '%s %s must start with ' +
       '"https://" or "//" or be relative and served from ' +
       'either https or from localhost. Invalid value: %s',
-      elementContext, urlString);
+      elementContext, sourceName, urlString);
   return urlString;
 }
 

diff --git a/test/functional/test-document-submit.js b/test/functional/test-document-submit.js
@@ -0,0 +1,106 @@
+/**
+ * Copyright 2016 The AMP HTML Authors. All Rights Reserved.
+ *
+ * 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 {onDocumentFormSubmit_} from '../../src/document-submit';
+import * as sinon from 'sinon';
+
+describe('test-document-submit onDocumentFormSubmit_', () => {
+  let sandbox;
+  let evt;
+  let tgt;
+  let preventDefaultSpy;
+
+  beforeEach(() => {
+    sandbox = sinon.sandbox.create();
+    preventDefaultSpy = sandbox.spy();
+    tgt = document.createElement('form');
+    tgt.action = 'https://www.google.com';
+    tgt.target = '_blank';
+    tgt.checkValidity = sandbox.stub();
+    evt = {
+      target: tgt,
+      preventDefault: preventDefaultSpy,
+      defaultPrevented: false,
+    };
+  });
+
+  afterEach(() => {
+    sandbox.restore();
+  });
+
+
+  it('should check target and action attributes', () => {
+    tgt.removeAttribute('action');
+    expect(() => onDocumentFormSubmit_(evt)).to.throw(
+        /form action attribute is required/);
+
+    tgt.setAttribute('action', 'http://example.com');
+    expect(() => onDocumentFormSubmit_(evt)).to.throw(
+        /form action must start with "https:/);
+
+    tgt.setAttribute('action', 'https://cdn.ampproject.org');
+    expect(() => onDocumentFormSubmit_(evt)).to.throw(
+        /form action should not be on cdn\.ampproject\.org/);
+
+    tgt.setAttribute('action', 'https://valid.example.com');
+    tgt.removeAttribute('target');
+    expect(() => onDocumentFormSubmit_(evt)).to.throw(
+        /form target attribute is required/);
+
+    tgt.setAttribute('target', '_self');
+    expect(() => onDocumentFormSubmit_(evt)).to.throw(
+        /form target=_self is invalid/);
+
+    tgt.setAttribute('target', '_blank');
+    expect(() => onDocumentFormSubmit_(evt)).to.not.throw;
+  });
+
+  it('should do nothing if already prevented', () => {
+    evt.defaultPrevented = true;
+    onDocumentFormSubmit_(evt);
+    expect(preventDefaultSpy.callCount).to.equal(0);
+    expect(tgt.checkValidity.callCount).to.equal(0);
+  });
+
+  it('should do nothing of no target', () => {
+    evt.target = null;
+    onDocumentFormSubmit_(evt);
+    expect(preventDefaultSpy.callCount).to.equal(0);
+    expect(tgt.checkValidity.callCount).to.equal(0);
+  });
+
+  it('should prevent submit', () => {
+    tgt.checkValidity = sandbox.stub().returns(false);
+    onDocumentFormSubmit_(evt);
+    expect(preventDefaultSpy.callCount).to.equal(1);
+    expect(tgt.checkValidity.callCount).to.equal(1);
+    sandbox.restore();
+    preventDefaultSpy.reset();
+    tgt.checkValidity.reset();
+
+    tgt.checkValidity = sandbox.stub().returns(false);
+    onDocumentFormSubmit_(evt);
+    expect(preventDefaultSpy.callCount).to.equal(1);
+    expect(tgt.checkValidity.callCount).to.equal(1);
+  });
+
+  it('should not prevent default', () => {
+    tgt.checkValidity = sandbox.stub().returns(true);
+    onDocumentFormSubmit_(evt);
+    expect(preventDefaultSpy.callCount).to.equal(0);
+    expect(tgt.checkValidity.callCount).to.equal(1);
+  });
+});
diff --git a/tools/experiments/experiments.js b/tools/experiments/experiments.js
@@ -86,6 +86,11 @@ const EXPERIMENTS = [
     name: 'AMP carousel using horizontal scroll',
     spec: '',
   },
+  {
+    id: 'form-submit',
+    name: 'Global document form submit handler',
+    spec: 'https://github.com/ampproject/amphtml/issues/3343',
+  },
 ];