/* * The MIT License * * Copyright (c) 2012 James Allardice * * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ // Defines the global Placeholders object along with various utility methods (function (global) { "use strict"; // Cross-browser DOM event binding function addEventListener(elem, event, fn) { if (elem.addEventListener) { return elem.addEventListener(event, fn, false); } if (elem.attachEvent) { return elem.attachEvent("on" + event, fn); } } // Check whether an item is in an array (we don't use Array.prototype.indexOf so we don't clobber any existing polyfills - this is a really simple alternative) function inArray(arr, item) { var i, len; for (i = 0, len = arr.length; i < len; i++) { if (arr[i] === item) { return true; } } return false; } // Move the caret to the index position specified. Assumes that the element has focus function moveCaret(elem, index) { var range; if (elem.createTextRange) { range = elem.createTextRange(); range.move("character", index); range.select(); } else if (elem.selectionStart) { elem.focus(); elem.setSelectionRange(index, index); } } // Attempt to change the type property of an input element function changeType(elem, type) { try { elem.type = type; return true; } catch (e) { // You can't change input type in IE8 and below return false; } } // Expose public methods global.Placeholders = { Utils: { addEventListener: addEventListener, inArray: inArray, moveCaret: moveCaret, changeType: changeType } }; }(this)); (function (global) { "use strict"; var validTypes = [ "text", "search", "url", "tel", "email", "password", "number", "textarea" ], // The list of keycodes that are not allowed when the polyfill is configured to hide-on-input badKeys = [ // The following keys all cause the caret to jump to the end of the input value 27, // Escape 33, // Page up 34, // Page down 35, // End 36, // Home // Arrow keys allow you to move the caret manually, which should be prevented when the placeholder is visible 37, // Left 38, // Up 39, // Right 40, // Down // The following keys allow you to modify the placeholder text by removing characters, which should be prevented when the placeholder is visible 8, // Backspace 46 // Delete ], // Styling variables placeholderStyleColor = "#ccc", placeholderClassName = "placeholdersjs", classNameRegExp = new RegExp("(?:^|\\s)" + placeholderClassName + "(?!\\S)"), // These will hold references to all elements that can be affected. NodeList objects are live, so we only need to get those references once inputs, textareas, // The various data-* attributes used by the polyfill ATTR_CURRENT_VAL = "data-placeholder-value", ATTR_ACTIVE = "data-placeholder-active", ATTR_INPUT_TYPE = "data-placeholder-type", ATTR_FORM_HANDLED = "data-placeholder-submit", ATTR_EVENTS_BOUND = "data-placeholder-bound", ATTR_OPTION_FOCUS = "data-placeholder-focus", ATTR_OPTION_LIVE = "data-placeholder-live", ATTR_MAXLENGTH = "data-placeholder-maxlength", // Various other variables used throughout the rest of the script test = document.createElement("input"), head = document.getElementsByTagName("head")[0], root = document.documentElement, Placeholders = global.Placeholders, Utils = Placeholders.Utils, hideOnInput, liveUpdates, keydownVal, styleElem, styleRules, placeholder, timer, form, elem, len, i; // No-op (used in place of public methods when native support is detected) function noop() {} // Avoid IE9 activeElement of death when an iframe is used. // More info: // http://bugs.jquery.com/ticket/13393 // https://github.com/jquery/jquery/commit/85fc5878b3c6af73f42d61eedf73013e7faae408 function safeActiveElement() { try { return document.activeElement; } catch (err) {} } // Hide the placeholder value on a single element. Returns true if the placeholder was hidden and false if it was not (because it wasn't visible in the first place) function hidePlaceholder(elem, keydownValue) { var type, maxLength, valueChanged = (!!keydownValue && elem.value !== keydownValue), isPlaceholderValue = (elem.value === elem.getAttribute(ATTR_CURRENT_VAL)); if ((valueChanged || isPlaceholderValue) && elem.getAttribute(ATTR_ACTIVE) === "true") { elem.removeAttribute(ATTR_ACTIVE); elem.value = elem.value.replace(elem.getAttribute(ATTR_CURRENT_VAL), ""); elem.className = elem.className.replace(classNameRegExp, ""); // Restore the maxlength value maxLength = elem.getAttribute(ATTR_MAXLENGTH); if (parseInt(maxLength, 10) >= 0) { // Old FF returns -1 if attribute not set (see GH-56) elem.setAttribute("maxLength", maxLength); elem.removeAttribute(ATTR_MAXLENGTH); } // If the polyfill has changed the type of the element we need to change it back type = elem.getAttribute(ATTR_INPUT_TYPE); if (type) { elem.type = type; } return true; } return false; } // Show the placeholder value on a single element. Returns true if the placeholder was shown and false if it was not (because it was already visible) function showPlaceholder(elem) { var type, maxLength, val = elem.getAttribute(ATTR_CURRENT_VAL); if (elem.value === "" && val) { elem.setAttribute(ATTR_ACTIVE, "true"); elem.value = val; elem.className += " " + placeholderClassName; // Store and remove the maxlength value maxLength = elem.getAttribute(ATTR_MAXLENGTH); if (!maxLength) { elem.setAttribute(ATTR_MAXLENGTH, elem.maxLength); elem.removeAttribute("maxLength"); } // If the type of element needs to change, change it (e.g. password inputs) type = elem.getAttribute(ATTR_INPUT_TYPE); if (type) { elem.type = "text"; } else if (elem.type === "password") { if (Utils.changeType(elem, "text")) { elem.setAttribute(ATTR_INPUT_TYPE, "password"); } } return true; } return false; } function handleElem(node, callback) { var handleInputsLength, handleTextareasLength, handleInputs, handleTextareas, elem, len, i; // Check if the passed in node is an input/textarea (in which case it can't have any affected descendants) if (node && node.getAttribute(ATTR_CURRENT_VAL)) { callback(node); } else { // If an element was passed in, get all affected descendants. Otherwise, get all affected elements in document handleInputs = node ? node.getElementsByTagName("input") : inputs; handleTextareas = node ? node.getElementsByTagName("textarea") : textareas; handleInputsLength = handleInputs ? handleInputs.length : 0; handleTextareasLength = handleTextareas ? handleTextareas.length : 0; // Run the callback for each element for (i = 0, len = handleInputsLength + handleTextareasLength; i < len; i++) { elem = i < handleInputsLength ? handleInputs[i] : handleTextareas[i - handleInputsLength]; callback(elem); } } } // Return all affected elements to their normal state (remove placeholder value if present) function disablePlaceholders(node) { handleElem(node, hidePlaceholder); } // Show the placeholder value on all appropriate elements function enablePlaceholders(node) { handleElem(node, showPlaceholder); } // Returns a function that is used as a focus event handler function makeFocusHandler(elem) { return function () { // Only hide the placeholder value if the (default) hide-on-focus behaviour is enabled if (hideOnInput && elem.value === elem.getAttribute(ATTR_CURRENT_VAL) && elem.getAttribute(ATTR_ACTIVE) === "true") { // Move the caret to the start of the input (this mimics the behaviour of all browsers that do not hide the placeholder on focus) Utils.moveCaret(elem, 0); } else { // Remove the placeholder hidePlaceholder(elem); } }; } // Returns a function that is used as a blur event handler function makeBlurHandler(elem) { return function () { showPlaceholder(elem); }; } // Functions that are used as a event handlers when the hide-on-input behaviour has been activated - very basic implementation of the "input" event function makeKeydownHandler(elem) { return function (e) { keydownVal = elem.value; //Prevent the use of the arrow keys (try to keep the cursor before the placeholder) if (elem.getAttribute(ATTR_ACTIVE) === "true") { if (keydownVal === elem.getAttribute(ATTR_CURRENT_VAL) && Utils.inArray(badKeys, e.keyCode)) { if (e.preventDefault) { e.preventDefault(); } return false; } } }; } function makeKeyupHandler(elem) { return function () { hidePlaceholder(elem, keydownVal); // If the element is now empty we need to show the placeholder if (elem.value === "") { elem.blur(); Utils.moveCaret(elem, 0); } }; } function makeClickHandler(elem) { return function () { if (elem === safeActiveElement() && elem.value === elem.getAttribute(ATTR_CURRENT_VAL) && elem.getAttribute(ATTR_ACTIVE) === "true") { Utils.moveCaret(elem, 0); } }; } // Returns a function that is used as a submit event handler on form elements that have children affected by this polyfill function makeSubmitHandler(form) { return function () { // Turn off placeholders on all appropriate descendant elements disablePlaceholders(form); }; } // Bind event handlers to an element that we need to affect with the polyfill function newElement(elem) { // If the element is part of a form, make sure the placeholder string is not submitted as a value if (elem.form) { form = elem.form; // If the type of the property is a string then we have a "form" attribute and need to get the real form if (typeof form === "string") { form = document.getElementById(form); } // Set a flag on the form so we know it's been handled (forms can contain multiple inputs) if (!form.getAttribute(ATTR_FORM_HANDLED)) { Utils.addEventListener(form, "submit", makeSubmitHandler(form)); form.setAttribute(ATTR_FORM_HANDLED, "true"); } } // Bind event handlers to the element so we can hide/show the placeholder as appropriate Utils.addEventListener(elem, "focus", makeFocusHandler(elem)); Utils.addEventListener(elem, "blur", makeBlurHandler(elem)); // If the placeholder should hide on input rather than on focus we need additional event handlers if (hideOnInput) { Utils.addEventListener(elem, "keydown", makeKeydownHandler(elem)); Utils.addEventListener(elem, "keyup", makeKeyupHandler(elem)); Utils.addEventListener(elem, "click", makeClickHandler(elem)); } // Remember that we've bound event handlers to this element elem.setAttribute(ATTR_EVENTS_BOUND, "true"); elem.setAttribute(ATTR_CURRENT_VAL, placeholder); // If the element doesn't have a value and is not focussed, set it to the placeholder string if (hideOnInput || elem !== safeActiveElement()) { showPlaceholder(elem); } } Placeholders.nativeSupport = test.placeholder !== void 0; if (!Placeholders.nativeSupport) { // Get references to all the input and textarea elements currently in the DOM (live NodeList objects to we only need to do this once) inputs = document.getElementsByTagName("input"); textareas = document.getElementsByTagName("textarea"); // Get any settings declared as data-* attributes on the root element (currently the only options are whether to hide the placeholder on focus or input and whether to auto-update) hideOnInput = root.getAttribute(ATTR_OPTION_FOCUS) === "false"; liveUpdates = root.getAttribute(ATTR_OPTION_LIVE) !== "false"; // Create style element for placeholder styles (instead of directly setting style properties on elements - allows for better flexibility alongside user-defined styles) styleElem = document.createElement("style"); styleElem.type = "text/css"; // Create style rules as text node styleRules = document.createTextNode("." + placeholderClassName + " { color:" + placeholderStyleColor + "; }"); // Append style rules to newly created stylesheet if (styleElem.styleSheet) { styleElem.styleSheet.cssText = styleRules.nodeValue; } else { styleElem.appendChild(styleRules); } // Prepend new style element to the head (before any existing stylesheets, so user-defined rules take precedence) head.insertBefore(styleElem, head.firstChild); // Set up the placeholders for (i = 0, len = inputs.length + textareas.length; i < len; i++) { elem = i < inputs.length ? inputs[i] : textareas[i - inputs.length]; // Get the value of the placeholder attribute, if any. IE10 emulating IE7 fails with getAttribute, hence the use of the attributes node placeholder = elem.attributes.placeholder; if (placeholder) { // IE returns an empty object instead of undefined if the attribute is not present placeholder = placeholder.nodeValue; // Only apply the polyfill if this element is of a type that supports placeholders, and has a placeholder attribute with a non-empty value if (placeholder && Utils.inArray(validTypes, elem.type)) { newElement(elem); } } } // If enabled, the polyfill will repeatedly check for changed/added elements and apply to those as well timer = setInterval(function () { for (i = 0, len = inputs.length + textareas.length; i < len; i++) { elem = i < inputs.length ? inputs[i] : textareas[i - inputs.length]; // Only apply the polyfill if this element is of a type that supports placeholders, and has a placeholder attribute with a non-empty value placeholder = elem.attributes.placeholder; if (placeholder) { placeholder = placeholder.nodeValue; if (placeholder && Utils.inArray(validTypes, elem.type)) { // If the element hasn't had event handlers bound to it then add them if (!elem.getAttribute(ATTR_EVENTS_BOUND)) { newElement(elem); } // If the placeholder value has changed or not been initialised yet we need to update the display if (placeholder !== elem.getAttribute(ATTR_CURRENT_VAL) || (elem.type === "password" && !elem.getAttribute(ATTR_INPUT_TYPE))) { // Attempt to change the type of password inputs (fails in IE < 9) if (elem.type === "password" && !elem.getAttribute(ATTR_INPUT_TYPE) && Utils.changeType(elem, "text")) { elem.setAttribute(ATTR_INPUT_TYPE, "password"); } // If the placeholder value has changed and the placeholder is currently on display we need to change it if (elem.value === elem.getAttribute(ATTR_CURRENT_VAL)) { elem.value = placeholder; } // Keep a reference to the current placeholder value in case it changes via another script elem.setAttribute(ATTR_CURRENT_VAL, placeholder); } } } else if (elem.getAttribute(ATTR_ACTIVE)) { hidePlaceholder(elem); elem.removeAttribute(ATTR_CURRENT_VAL); } } // If live updates are not enabled cancel the timer if (!liveUpdates) { clearInterval(timer); } }, 100); } Utils.addEventListener(global, "beforeunload", function () { Placeholders.disable(); }); // Expose public methods Placeholders.disable = Placeholders.nativeSupport ? noop : disablePlaceholders; Placeholders.enable = Placeholders.nativeSupport ? noop : enablePlaceholders; }(this));