Upstream injected JavaScript for the iOS web layer

ios/web/web_state/js/resources/common.js

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file provides common methods that can be shared by other JavaScripts.
+
+/**
+ * Namespace for this file. It depends on |__gCrWeb| having already been
+ * injected. String 'common' is used in |__gCrWeb['common']| as it needs to be
+ * accessed in Objective-C code.
+ */
+__gCrWeb['common'] = {};
+
+/* Beginning of anonymous object. */
+new function() {
+  // JSON safe object to protect against custom implementation of Object.toJSON
+  // in host pages.
+  __gCrWeb['common'].JSONSafeObject = function JSONSafeObject() {
+  };
+
+  /**
+   * Protect against custom implementation of Object.toJSON in host pages.
+   */
+  __gCrWeb['common'].JSONSafeObject.prototype.toJSON = null;
+
+  /**
+   * Retain the original JSON.stringify method where possible to reduce the
+   * impact of sites overriding it
+   */
+  __gCrWeb.common.JSONStringify = JSON.stringify;
+
+  /**
+   * Prefix used in references to form elements that have no 'id' or 'name'
+   */
+  __gCrWeb.common.kNamelessFormIDPrefix = 'gChrome~';
+
+  /**
+   * Tests an element's visiblity. This test is expensive so should be used
+   * sparingly.
+   * @param {Element} element A DOM element.
+   * @return {boolean} true if the |element| is currently part of the visible
+   * DOM.
+   */
+  __gCrWeb.common.isElementVisible = function(element) {
+    while (element !== document) {
+      var style = window.getComputedStyle(element);
+      if (style.display === 'none' || style.visibility === 'hidden') {
+        return false;
+      }
+      // Move up the tree and test again.
+      element = element.parentNode;
+    }
+    // Test reached the top of the DOM without finding a concealed ancestor.
+    return true;
+  };
+
+  /**
+   * Based on Element::isFormControlElement() (WebKit)
+   * @param {Element} element A DOM element.
+   * @return {boolean} true if the |element| is a form control element.
+   */
+  __gCrWeb.common.isFormControlElement = function(element) {
+    var tagName = element.tagName;
+    return (tagName === 'INPUT' ||
+            tagName === 'SELECT' ||
+            tagName === 'TEXTAREA');
+  };
+
+  /**
+   * Detects focusable elements.
+   * @param {Element} element A DOM element.
+   * @return {boolean} true if the |element| is focusable.
+   */
+  __gCrWeb.common.isFocusable = function(element) {
+    // When the disabled or hidden attributes are present, controls do not
+    // receive focus.
+    if (element.hasAttribute('disabled') || element.hasAttribute('hidden'))
+      return false;
+    return __gCrWeb.common.isFormControlElement(element);
+  };
+
+  /**
+   * Returns an array of control elements in a form.
+   *
+   * This method is based on the logic in method
+   *     void WebFormElement::getFormControlElements(
+   *         WebVector<WebFormControlElement>&) const
+   * in chromium/src/third_party/WebKit/Source/WebKit/chromium/src/
+   * WebFormElement.cpp.
+   *
+   * @param {Element} form A form element for which the control elements are
+   *   returned.
+   * @return {Array.<Element>}
+   */
+  __gCrWeb.common.getFormControlElements = function(form) {
+    if (!form) {
+      return [];
+    }
+    var results = [];
+    // Get input and select elements from form.elements.
+    // TODO(chenyu): according to
+    // http://www.w3.org/TR/2011/WD-html5-20110525/forms.html, form.elements are
+    // the "listed elements whose form owner is the form element, with the
+    // exception of input elements whose type attribute is in the Image Button
+    // state, which must, for historical reasons, be excluded from this
+    // particular collection." In WebFormElement.cpp, this method is implemented
+    // by returning elements in form's associated elements that have tag 'INPUT'
+    // or 'SELECT'. Check if input Image Buttons are excluded in that
+    // implementation. Note for Autofill, as input Image Button is not
+    // considered as autofillable elements, there is no impact on Autofill
+    // feature.
+    var elements = form.elements;
+    for (var i = 0; i < elements.length; i++) {
+      if (__gCrWeb.common.isFormControlElement(elements[i])) {
+        results.push(elements[i]);
+      }
+    }
+    return results;
+  };
+
+  /**
+   * Returns true if an element can be autocompleted.
+   *
+   * This method aims to provide the same logic as method
+   *     bool autoComplete() const
+   * in chromium/src/third_party/WebKit/Source/WebKit/chromium/src/
+   * WebFormElement.cpp.
+   *
+   * @param {Element} element An element to check if it can be autocompleted.
+   * @return {boolean} true if element can be autocompleted.
+   */
+  __gCrWeb.common.autoComplete = function(element) {
+    if (!element) {
+      return false;
+    }
+    if (__gCrWeb.common.getLowerCaseAttribute(
+        element, 'autocomplete') == 'off') {
+      return false;
+    }
+    if (__gCrWeb.common.getLowerCaseAttribute(
+            element.form, 'autocomplete') == 'off') {
+      return false;
+    }
+    return true;
+  };
+
+  /**
+   * Returns if an element is a text field.
+   * This returns true for all of textfield-looking types such as text,
+   * password, search, email, url, and number.
+   *
+   * This method aims to provide the same logic as method
+   *     bool WebInputElement::isTextField() const
+   * in chromium/src/third_party/WebKit/Source/WebKit/chromium/src/
+   * WebInputElement.cpp, where this information is from
+   *     bool HTMLInputElement::isTextField() const
+   *     {
+   *       return m_inputType->isTextField();
+   *     }
+   * (chromium/src/third_party/WebKit/Source/WebCore/html/HTMLInputElement.cpp)
+   *
+   * The implementation here is based on the following:
+   *
+   * - Method bool InputType::isTextField() defaults to be false and it is
+   *   override to return true only in HTMLInputElement's subclass
+   *   TextFieldInputType (chromium/src/third_party/WebKit/Source/WebCore/html/
+   *   TextFieldInputType.h).
+   *
+   * - The implementation here considers all the subclasses of
+   *   TextFieldInputType: NumberInputType and BaseTextInputType, which has
+   *   subclasses EmailInputType, PasswordInputType, SearchInputType,
+   *   TelephoneInputType, TextInputType, URLInputType. (All these classes are
+   *   defined in chromium/src/third_party/WebKit/Source/WebCore/html/)
+   *
+   * @param {Element} element An element to examine if it is a text field.
+   * @return {boolean} true if element has type=text.
+   */
+  __gCrWeb.common.isTextField = function(element) {
+    if (!element) {
+      return false;
+    }
+    if (element.type === 'hidden') {
+      return false;
+    }
+    return element.type === 'text' ||
+           element.type === 'email' ||
+           element.type === 'password' ||
+           element.type === 'search' ||
+           element.type === 'tel' ||
+           element.type === 'url' ||
+           element.type === 'number';
+  };
+
+  /**
+   * Sets the checked value of an input and dispatches an change event if
+   * |shouldSendChangeEvent|.
+   *
+   * This is a simplified version of the implementation of
+   *
+   *     void setChecked(bool nowChecked, TextFieldEventBehavior eventBehavior)
+   *
+   * in chromium/src/third_party/WebKit/Source/WebKit/chromium/src/
+   * WebInputElement.cpp, which calls
+   *     void HTMLInputElement::setChecked(
+   *         bool nowChecked, TextFieldEventBehavior eventBehavior)
+   * in chromium/src/third_party/WebKit/Source/core/html/HTMLInputElement.cpp.
+   *
+   * @param {boolean} nowChecked The new checked value of the input element.
+   * @param {Element} input The input element of which the value is set.
+   * @param {boolean} shouldSendChangeEvent Whether a change event should be
+   *     dispatched.
+   */
+  __gCrWeb.common.setInputElementChecked = function(
+      nowChecked, input, shouldSendChangeEvent) {
+    var checkedChanged = input.checked !== nowChecked;
+    input.checked = nowChecked;
+    if (checkedChanged) {
+      __gCrWeb.common.createAndDispatchHTMLEvent(input, 'change', true, false);
+    }
+  };
+
+  /**
+   * Sets the value of an input and dispatches an change event if
+   * |shouldSendChangeEvent|.
+   *
+   * It is based on the logic in
+   *
+   *     void setValue(const WebString&, bool sendChangeEvent = false)
+   *
+   * in chromium/src/third_party/WebKit/Source/WebKit/chromium/src/
+   * WebInputElement.cpp, which calls
+   *    void setValue(const String& value, TextFieldEventBehavior eventBehavior)
+   * in chromium/src/third_party/WebKit/Source/core/html/HTMLInputElement.cpp.
+   *
+   * @param {string} value The value the input element will be set.
+   * @param {Element} input The input element of which the value is set.
+   * @param {boolean} shouldSendChangeEvent Whether a change event should be
+   *     dispatched.
+   */
+  __gCrWeb.common.setInputElementValue = function(
+      value, input, shouldSendChangeEvent) {
+    // In HTMLInputElement.cpp there is a check on canSetValue(value), which
+    // returns false only for file input. As file input is not relevant for
+    // autofill and this method is only used for autofill for now, there is no
+    // such check in this implementation.
+    var sanitizedValue = __gCrWeb.common.sanitizeValueForInputElement(
+        value, input);
+    var valueChanged = sanitizedValue !== input.value;
+    input.value = sanitizedValue;
+    if (valueChanged) {
+      __gCrWeb.common.createAndDispatchHTMLEvent(input, 'change', true, false);
+    }
+  };
+
+  /**
+   * Returns a sanitized value of proposedValue for a given input element type.
+   * The logic is based on
+   *
+   *      String sanitizeValue(const String&) const
+   *
+   * in chromium/src/third_party/WebKit/Source/core/html/InputType.h
+   *
+   * @param {string} proposedValue The proposed value.
+   * @param {Element} element The element for which the proposedValue is to be
+   *     sanitized.
+   * @return {string} The sanitized value.
+   */
+   __gCrWeb.common.sanitizeValueForInputElement = function(
+       proposedValue, element) {
+    if (!proposedValue) {
+      return null;
+    }
+
+    // Method HTMLInputElement::sanitizeValue() calls InputType::sanitizeValue()
+    // (chromium/src/third_party/WebKit/Source/core/html/InputType.cpp) for
+    // non-null proposedValue. InputType::sanitizeValue() returns the original
+    // proposedValue by default and it is overridden in classes
+    // BaseDateAndTimeInputType, ColorInputType, RangeInputType and
+    // TextFieldInputType (all are in
+    // chromium/src/third_party/WebKit/Source/core/html/). Currently only
+    // TextFieldInputType is relevant and sanitizeValue() for other types of
+    // input elements has not been implemented.
+    if (__gCrWeb.common.isTextField(element)) {
+      return __gCrWeb.common.sanitizeValueForTextFieldInputType(
+          proposedValue, element);
+    }
+    return proposedValue;
+   };
+
+  /**
+   * Returns a sanitized value for a text field.
+   *
+   * The logic is based on |String sanitizeValue(const String&)|
+   * in chromium/src/third_party/WebKit/Source/core/html/TextFieldInputType.h
+   * Note this method is overridden in EmailInputType and NumberInputType.
+   *
+   * @param {string} proposedValue The proposed value.
+   * @param {Element} element The element for which the proposedValue is to be
+   *     sanitized.
+   * @return {string} The sanitized value.
+   */
+  __gCrWeb.common.sanitizeValueForTextFieldInputType = function(
+      proposedValue, element) {
+    var textFieldElementType = element.type;
+    if (textFieldElementType === 'email') {
+      return __gCrWeb.common.sanitizeValueForEmailInputType(
+          proposedValue, element);
+    } else if (textFieldElementType === 'number') {
+      return __gCrWeb.common.sanitizeValueForNumberInputType(proposedValue);
+    }
+    var valueWithLineBreakRemoved = proposedValue.replace(/(\r\n|\n|\r)/gm, '');
+    // TODO(chenyu): Should we also implement numCharactersInGraphemeClusters()
+    // in chromium/src/third_party/WebKit/Source/core/platform/text/
+    // TextBreakIterator.cpp and call it here when computing newLength?
+    // Different from the implementation in TextFieldInputType.h, where a limit
+    // on the text length is considered due to
+    // https://bugs.webkit.org/show_bug.cgi?id=14536, no such limit is
+    // considered here for now.
+    var newLength = valueWithLineBreakRemoved.length;
+    // This logic is from method String limitLength() in TextFieldInputType.h
+    for (var i = 0; i < newLength; ++i) {
+      var current = valueWithLineBreakRemoved[i];
+      if (current < ' ' && current != '\t') {
+        newLength = i;
+        break;
+      }
+    }
+    return valueWithLineBreakRemoved.substring(0, newLength);
+  };
+
+  /**
+   * Returns the sanitized value for an email input.
+   *
+   * The logic is based on
+   *
+   *     String EmailInputType::sanitizeValue(const String& proposedValue) const
+   *
+   * in chromium/src/third_party/WebKit/Source/core/html/EmailInputType.cpp
+   *
+   * @param {string} proposedValue The proposed value.
+   * @param {Element} element The element for which the proposedValue is to be
+   *     sanitized.
+   * @return {string} The sanitized value.
+   */
+  __gCrWeb.common.sanitizeValueForEmailInputType = function(
+      proposedValue, element) {
+    var valueWithLineBreakRemoved = proposedValue.replace(/(\r\n|\n\r)/gm, '');
+
+    if (!element.multiple) {
+      return __gCrWeb.common.trim(proposedValue);
+    }
+    var addresses = valueWithLineBreakRemoved.split(',');
+    for (var i = 0; i < addresses.length; ++i) {
+      addresses[i] = __gCrWeb.common.trim(addresses[i]);
+    }
+    return addresses.join(',');
+  };
+
+  /**
+   * Returns the sanitized value of a proposed value for a number input.
+   *
+   * The logic is based on
+   *
+   *     String NumberInputType::sanitizeValue(const String& proposedValue)
+   *         const
+   *
+   * in chromium/src/third_party/WebKit/Source/core/html/NumberInputType.cpp
+   *
+   * Note in this implementation method Number() is used in the place of method
+   * parseToDoubleForNumberType() called in NumberInputType.cpp.
+   *
+   * @param {string} proposedValue The proposed value.
+   * @return {string} The sanitized value.
+   */
+  __gCrWeb.common.sanitizeValueForNumberInputType = function(proposedValue) {
+    var sanitizedValue = Number(proposedValue);
+    if (isNaN(sanitizedValue)) {
+      return '';
+    }
+    return sanitizedValue;
+  };
+
+  /**
+   * Trims any whitespace from the start and end of a string.
+   * Used in preference to String.prototype.trim as this can be overridden by
+   * sites.
+   *
+   * @param {string} str The string to be trimmed.
+   * @return {string} The string after trimming.
+   */
+  __gCrWeb.common.trim = function(str) {
+    return str.replace(/^\s+|\s+$/g, '');
+  };
+
+  /**
+   * Returns the name that should be used for the specified |element| when
+   * storing Autofill data. Various attributes are used to attempt to identify
+   * the element, beginning with 'name' and 'id' attributes. Providing a
+   * uniquely reversible identifier for any element is a non-trivial problem;
+   * this solution attempts to satisfy the majority of cases.
+   *
+   * It aims to provide the logic in
+   *     WebString nameForAutofill() const;
+   * in chromium/src/third_party/WebKit/Source/WebKit/chromium/public/
+   *  WebFormControlElement.h
+   *
+   * @param {Element} element An element of which the name for Autofill will be
+   *     returned.
+   * @return {string} the name for Autofill.
+   */
+  __gCrWeb.common.nameForAutofill = function(element) {
+    if (!element) {
+      return '';
+    }
+    var trimmedName = element.name;
+    if (trimmedName) {
+      trimmedName = __gCrWeb.common.trim(trimmedName);
+      if (trimmedName.length > 0) {
+        return trimmedName;
+      }
+    }
+    trimmedName = element.getAttribute('id');
+    if (trimmedName) {
+      return __gCrWeb.common.trim(trimmedName);
+    }
+    trimmedName = element.getAttribute('autocomplete');
+    if (trimmedName && trimmedName !== 'off') {
+      return __gCrWeb.common.trim(trimmedName);
+    }
+    trimmedName = element.getAttribute('placeholder');
+    if (trimmedName) {
+      return __gCrWeb.common.trim(trimmedName);
+    }
+    return '';
+  };
+
+  /**
+   * Acquires the specified DOM |attribute| from the DOM |element| and returns
+   * its lower-case value, or null if not present.
+   * @param {Element} element A DOM element.
+   * @param {string} attribute An attribute name.
+   * @return {?string} Lowercase value of DOM element or null if not present.
+   */
+  __gCrWeb.common.getLowerCaseAttribute = function(element, attribute) {
+    if (!element) {
+      return null;
+    }
+    var value = element.getAttribute(attribute);
+    if (value) {
+      return value.toLowerCase();
+    }
+    return null;
+  };
+
+  /**
+   * Converts a relative URL into an absolute URL.
+   * @param {Object} doc Document.
+   * @param {string} relativeURL Relative URL.
+   * @return {string} Absolute URL.
+   */
+  __gCrWeb.common.absoluteURL = function(doc, relativeURL) {
+    // In the case of data: URL-based pages, relativeURL === absoluteURL.
+    if (doc.location.protocol === 'data:') {
+      return doc.location.href;
+    }
+    var urlNormalizer = doc['__gCrWebURLNormalizer'];
+    if (!urlNormalizer) {
+      urlNormalizer = doc.createElement('a');
+      doc['__gCrWebURLNormalizer'] = urlNormalizer;
+    }
+
+    // Use the magical quality of the <a> element. It automatically converts
+    // relative URLs into absolute ones.
+    urlNormalizer.href = relativeURL;
+    return urlNormalizer.href;
+  };
+
+  /**
+   * Extracts the webpage URL from the given URL by removing the query
+   * and the reference (aka fragment) from the URL.
+   * @param {string} url Web page URL.
+   * @return {string} Web page URL with query and reference removed.
+   */
+  __gCrWeb.common.removeQueryAndReferenceFromURL = function(url) {
+    var queryIndex = url.indexOf('?');
+    if (queryIndex != -1) {
+      return url.substring(0, queryIndex);
+    }
+
+    var hashIndex = url.indexOf('#');
+    if (hashIndex != -1) {
+      return url.substring(0, hashIndex);
+    }
+    return url;
+  };
+
+  /**
+   * Returns the form's |name| attribute if non-empty; otherwise the form's |id|
+   * attribute, or the index of the form (with prefix) in document.forms.
+   *
+   * It is partially based on the logic in
+   *     const string16 GetFormIdentifier(const blink::WebFormElement& form)
+   * in chromium/src/components/autofill/renderer/form_autofill_util.h.
+   *
+   * @param {Element} form An element for which the identifier is returned.
+   * @return {string} a string that represents the element's identifier.
+   */
+  __gCrWeb.common.getFormIdentifier = function(form) {
+    if (!form)
+      return '';
+    var name = form.getAttribute('name');
+    if (name && name.length != 0) {
+      return name;
+    }
+    name = form.getAttribute('id');
+    if (name) {
+      return name;
+    }
+    // A form name must be supplied, because the element will later need to be
+    // identified from the name. A last resort is to take the index number of
+    // the form in document.forms. ids are not supposed to begin with digits (by
+    // HTML 4 spec) so this is unlikely to match a true id.
+    for (var idx = 0; idx != document.forms.length; idx++) {
+      if (document.forms[idx] == form) {
+        return __gCrWeb.common.kNamelessFormIDPrefix + idx;
+      }
+    }
+    return '';
+  };
+
+  /**
+   * Returns the form element from an ID obtained from getFormIdentifier.
+   *
+   * This works on a 'best effort' basis since DOM changes can always change the
+   * actual element that the ID refers to.
+   *
+   * @param {string} name An ID string obtained via getFormIdentifier.
+   * @return {Element} The original form element, if it can be determined.
+   */
+  __gCrWeb.common.getFormElementFromIdentifier = function(name) {
+    // First attempt is from the name / id supplied.
+    var form = document.forms.namedItem(name);
+    if (form) {
+      return form;
+    }
+    // Second attempt is from the prefixed index position of the form in
+    // document.forms.
+    if (name.indexOf(__gCrWeb.common.kNamelessFormIDPrefix) == 0) {
+      var nameAsInteger = 0 |
+          name.substring(__gCrWeb.common.kNamelessFormIDPrefix.length);
+      if (__gCrWeb.common.kNamelessFormIDPrefix + nameAsInteger == name &&
+          nameAsInteger < document.forms.length) {
+        return document.forms[nameAsInteger];
+      }
+    }
+    return null;
+  };
+
+  /**
+   * Creates and dispatches an HTML event.
+   *
+   * @param {Element} element The element for which an event is created.
+   * @param {string} type The type of the event.
+   * @param {boolean} bubbles A boolean indicating whether the event should
+   *     bubble up through the event chain or not.
+   * @param {boolean} cancelable A boolean indicating whether the event can be
+   *     canceled.
+   */
+  __gCrWeb.common.createAndDispatchHTMLEvent = function(
+      element, type, bubbles, cancelable) {
+    var changeEvent = element.ownerDocument.createEvent('HTMLEvents');
+    changeEvent.initEvent(type, bubbles, cancelable);
+
+    // A timer is used to avoid reentering JavaScript evaluation.
+    window.setTimeout(function() {
+      element.dispatchEvent(changeEvent);
+    }, 0);
+  };
+}  // End of anonymous object