/*
* 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",
// 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() {}
// 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) {
var type;
if (elem.value === elem.getAttribute(ATTR_CURRENT_VAL) && elem.getAttribute(ATTR_ACTIVE) === "true") {
elem.setAttribute(ATTR_ACTIVE, "false");
elem.value = "";
elem.className = elem.className.replace(classNameRegExp, "");
// 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,
val = elem.getAttribute(ATTR_CURRENT_VAL);
if (elem.value === "" && val) {
elem.setAttribute(ATTR_ACTIVE, "true");
elem.value = val;
elem.className += " " + placeholderClassName;
// 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 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;
// Run the callback for each element
for (i = 0, len = handleInputs.length + handleTextareas.length; i < len; i++) {
elem = i < handleInputs.length ? handleInputs[i] : handleTextareas[i - handleInputs.length];
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 () {
var type;
if (elem.getAttribute(ATTR_ACTIVE) === "true" && elem.value !== keydownVal) {
// Remove the placeholder
elem.className = elem.className.replace(classNameRegExp, "");
elem.value = elem.value.replace(elem.getAttribute(ATTR_CURRENT_VAL), "");
elem.setAttribute(ATTR_ACTIVE, false);
// If the type of element needs to change, change it (e.g. password inputs)
type = elem.getAttribute(ATTR_INPUT_TYPE);
if (type) {
elem.type = type;
}
}
// 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 === document.activeElement && 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;
// 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, set it to the placeholder string
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);
}
}
}
}
// If live updates are not enabled cancel the timer
if (!liveUpdates) {
clearInterval(timer);
}
}, 100);
}
// Expose public methods
Placeholders.disable = Placeholders.nativeSupport ? noop : disablePlaceholders;
Placeholders.enable = Placeholders.nativeSupport ? noop : enablePlaceholders;
}(this));
