Countable.js
/**
* Countable is a script to allow for live paragraph-, word- and character-
* counting on an HTML element.
*
* @author Sacha Schmid (<https://github.com/RadLikeWhoa>)
* @version 3.0.1
* @license MIT
* @see <http://radlikewhoa.github.io/Countable/>
*/
/**
* Note: For the purpose of this internal documentation, arguments of the type
* {Nodes} are to be interpreted as either {NodeList} or {Element}.
*/
;(function (global) {
'use strict'
/**
* @private
*
* `liveElements` holds all elements that have the live-counting
* functionality bound to them.
*/
let liveElements = []
const each = Array.prototype.forEach
/**
* `ucs2decode` function from the punycode.js library.
*
* Creates an array containing the decimal code points of each Unicode
* character in the string. While JavaScript uses UCS-2 internally, this
* function will convert a pair of surrogate halves (each of which UCS-2
* exposes as separate characters) into a single code point, matching
* UTF-16.
*
* @see <http://goo.gl/8M09r>
* @see <http://goo.gl/u4UUC>
*
* @param {String} string The Unicode input string (UCS-2).
*
* @return {Array} The new array of code points.
*/
function decode (string) {
const output = []
let counter = 0
const length = string.length
while (counter < length) {
const value = string.charCodeAt(counter++)
if (value >= 0xD800 && value <= 0xDBFF && counter < length) {
// It's a high surrogate, and there is a next character.
const extra = string.charCodeAt(counter++)
if ((extra & 0xFC00) == 0xDC00) { // Low surrogate.
output.push(((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000)
} else {
// It's an unmatched surrogate; only append this code unit, in case the
// next code unit is the high surrogate of a surrogate pair.
output.push(value)
counter--
}
} else {
output.push(value)
}
}
return output
}
/**
* `validateArguments` validates the arguments given to each function call.
* Errors are logged to the console as warnings, but Countable fails
* silently.
*
* @private
*
* @param {Nodes|String} targets A (collection of) element(s) or a single
* string to validate.
*
* @param {Function} callback The callback function to validate.
*
* @return {Boolean} Returns whether all arguments are valid.
*/
function validateArguments (targets, callback) {
const nodes = Object.prototype.toString.call(targets)
const targetsValid = typeof targets === 'string' || ((nodes === '[object NodeList]' || nodes === '[object HTMLCollection]') || targets.nodeType === 1)
const callbackValid = typeof callback === 'function'
if (!targetsValid) console.error('Countable: Not a valid target')
if (!callbackValid) console.error('Countable: Not a valid callback function')
return targetsValid && callbackValid
}
/**
* `count` trims an element's value, optionally strips HTML tags and counts
* paragraphs, sentences, words, characters and characters plus spaces.
*
* @private
*
* @param {Node|String} target The target for the count.
*
* @param {Object} options The options to use for the counting.
*
* @return {Object} The object containing the number of paragraphs,
* sentences, words, characters and characters
* plus spaces.
*/
function count (target, options) {
let original = '' + (typeof target === 'string' ? target : ('value' in target ? target.value : target.textContent))
options = options || {}
/**
* The initial implementation to allow for HTML tags stripping was created
* @craniumslows while the current one was created by @Rob--W.
*
* @see <http://goo.gl/Exmlr>
* @see <http://goo.gl/gFQQh>
*/
if (options.stripTags) original = original.replace(/<\/?[a-z][^>]*>/gi, '')
if (options.ignore) {
each.call(options.ignore, function (i) {
original = original.replace(i, '')
})
}
const trimmed = original.trim()
/**
* Most of the performance improvements are based on the works of @epmatsw.
*
* @see <http://goo.gl/SWOLB>
*/
return {
paragraphs: trimmed ? (trimmed.match(options.hardReturns ? /\n{2,}/g : /\n+/g) || []).length + 1 : 0,
sentences: trimmed ? (trimmed.match(/[.?!…]+./g) || []).length + 1 : 0,
words: trimmed ? (trimmed.replace(/['";:,.?¿\-!¡]+/g, '').match(/\S+/g) || []).length : 0,
characters: trimmed ? decode(trimmed.replace(/\s/g, '')).length : 0,
all: decode(original).length
}
}
/**
* This is the main object that will later be exposed to other scripts. It
* holds all the public methods that can be used to enable the Countable
* functionality.
*
* Some methods accept an optional options parameter. This includes the
* following options.
*
* {Boolean} hardReturns Use two returns to seperate a paragraph
* instead of one. (default: false)
* {Boolean} stripTags Strip HTML tags before counting the values.
* (default: false)
* {Array<Char>} ignore A list of characters that should be removed
* ignored when calculating the counters.
* (default: )
*/
const Countable = {
/**
* The `on` method binds the counting handler to all given elements. The
* event is either `oninput` or `onkeydown`, based on the capabilities of
* the browser.
*
* @param {Nodes} elements All elements that should receive the
* Countable functionality.
*
* @param {Function} callback The callback to fire whenever the
* element's value changes. The callback is
* called with the relevant element bound
* to `this` and the counted values as the
* single parameter.
*
* @param {Object} [options] An object to modify Countable's
* behaviour.
*
* @return {Object} Returns the Countable object to allow for chaining.
*/
on: function (elements, callback, options) {
if (!validateArguments(elements, callback)) return
if (!Array.isArray(elements)) {
elements = [ elements ]
}
each.call(elements, function (e) {
const handler = function () {
callback.call(e, count(e, options))
}
liveElements.push({ element: e, handler: handler })
handler()
e.addEventListener('input', handler)
})
return this
},
/**
* The `off` method removes the Countable functionality from all given
* elements.
*
* @param {Nodes} elements All elements whose Countable functionality
* should be unbound.
*
* @return {Object} Returns the Countable object to allow for chaining.
*/
off: function (elements) {
if (!validateArguments(elements, function () {})) return
if (!Array.isArray(elements)) {
elements = [ elements ]
}
liveElements.filter(function (e) {
return elements.indexOf(e.element) !== -1
}).forEach(function (e) {
e.element.removeEventListener('input', e.handler)
})
liveElements = liveElements.filter(function (e) {
return elements.indexOf(e.element) === -1
})
return this
},
/**
* The `count` method works mostly like the `live` method, but no events are
* bound, the functionality is only executed once.
*
* @param {Nodes|String} targets All elements that should be counted.
*
* @param {Function} callback The callback to fire whenever the
* element's value changes. The callback
* is called with the relevant element
* bound to `this` and the counted values
* as the single parameter.
*
* @param {Object} [options] An object to modify Countable's
* behaviour.
*
* @return {Object} Returns the Countable object to allow for chaining.
*/
count: function (targets, callback, options) {
if (!validateArguments(targets, callback)) return
if (!Array.isArray(targets)) {
targets = [ targets ]
}
each.call(targets, function (e) {
callback.call(e, count(e, options))
})
return this
},
/**
* The `enabled` method checks if the live-counting functionality is bound
* to an element.
*
* @param {Node} element All elements that should be checked for the
* Countable functionality.
*
* @return {Boolean} A boolean value representing whether Countable
* functionality is bound to all given elements.
*/
enabled: function (elements) {
if (elements.length === undefined) {
elements = [ elements ]
}
return liveElements.filter(function (e) {
return elements.indexOf(e.element) !== -1
}).length === elements.length
}
}
/**
* Expose Countable depending on the module system used across the
* application. (Node / CommonJS, AMD, global)
*/
if (typeof exports === 'object') {
module.exports = Countable
} else if (typeof define === 'function' && define.amd) {
define(function () { return Countable })
} else {
global.Countable = Countable
}
}(this));