Port of Yii2 BaseHtml class that provides a set of static methods for generating commonly used HTML tags

baseHtml.js

/**
 * Returns whether given variable is undefined
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param variable
 * @returns {boolean}
 */
function isUndefined(variable) {
	return (typeof(variable) === typeof(undefined));
}

/**
 * Returns whether given variable is defined
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param variable
 * @returns {boolean}
 */
function isDefined(variable) {
	return !isUndefined(variable);
}

/**
 * Returns whether given variable is a string
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param variable
 * @returns {boolean}
 */
function isString(variable) {
	return (typeof(variable) === 'string' || variable instanceof String);
}

/**
 * Returns whether given variable is an array
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param variable
 * @returns {boolean}
 */
function isArray(variable) {
	return (Object.prototype.toString.call(variable) === '[object Array]');
}

/**
 * Returns whether given variable is function
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param variable
 * @returns {boolean}
 */
function isFunction(variable) {
	return Object.prototype.toString.call(variable) == '[object Function]';
}

/**
 * Returns whether given variable is boolean
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param variable
 * @returns {boolean}
 */
function isBool(variable) {
	return (typeof(variable) === 'Boolean');
}

/**
 * Returns whether given variable is empty array or object
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param obj
 * @returns {boolean}
 */
function isEmpty(obj) {
	if (obj == null) return true;
	if (obj.length > 0) return false;
	if (obj.length === 0) return true;
	for (var key in obj) {
		if (obj.hasOwnProperty(key)) return false;
	}
	return true;
}

/**
 * Returns an object that is amalgamation of two given objects
 *
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @param obj1
 * @param obj2
 * @returns {object}
 */
function mergeOptions(obj1, obj2) {
	var obj3 = {}, attrname;
	for (attrname in obj1) {
		if (obj1.hasOwnProperty(attrname)) {
			obj3[attrname] = obj1[attrname];
		}
	}
	for (attrname in obj2) {
		if (obj2.hasOwnProperty(attrname)) {
			obj3[attrname] = obj2[attrname];
		}
	}
	return obj3;
}

/**
 * BaseHtml provides a set of static methods for generating commonly used HTML tags
 *
 * Port of Yii2 BaseHtml class (http://www.yiiframework.com/doc-2.0/yii-helpers-basehtml.html) with small
 * modifications, that require server-side capabilities (like CSRF)
 *
 *     var h = BaseHtml();
 *     h.tag('div', 'Foo bar', {'class': 'foo-bar-container'})
 * @author Nils Lindentals <nils@dfworks.lv>
 * @license GNU GPL v2.0
 *
 * @class BaseHtml
 * @constructor
 *
 * @requires {Function} isDefined()
 * @requires {Function} isUndefined()
 * @requires {Function} isBool()
 * @requires {Function} isArray()
 * @requires {Function} isEmpty()
 * @requires {Function} mergeOptions()
 * @requires {Function} htmlspecialchars() https://github.com/kvz/phpjs/blob/master/functions/strings/htmlspecialchars.js
 * @requires {Function} htmlspecialchars_decode() https://github.com/kvz/phpjs/blob/master/functions/strings/htmlspecialchars_decode.js
 * @requires {Function} strcasecmp() https://github.com/kvz/phpjs/blob/master/functions/strings/strcasecmp.js
 * @requires {Function} urldecode() https://github.com/kvz/phpjs/blob/master/functions/url/urldecode.js
 * @requires {Function} implode() https://github.com/kvz/phpjs/blob/master/functions/strings/implode.js
 * @requires {Function} strpos() https://github.com/kvz/phpjs/blob/master/functions/strings/strpos.js
 * @requires {Function} substr() https://github.com/kvz/phpjs/blob/master/functions/strings/substr.js
 * @requires {Function} explode() https://github.com/kvz/phpjs/blob/master/functions/strings/explode.js
 *
 * @returns {{
 *     encode: encode,
 *     decode: decode,
 *     renderTagAttributes: renderTagAttributes,
 *     renderTagAttributes: renderTagAttributes,
 *     tag: tag,
 *     beginTag: beginTag,
 *     endTag: endTag,
 *     style: style,
 *     script: script,
 *     cssFile: cssFile,
 *     jsFile: jsFile,
 *     hiddenInput: hiddenInput,
 *     beginForm: beginForm,
 *     endForm: endForm,
 *     a: a,
 *     mailto: mailto,
 *     img: img,
 *     label: label,
 *     button: button,
 *     submitButton: submitButton,
 *     resetButton: resetButton,
 *     input: input,
 *     buttonInput: buttonInput,
 *     submitInput: submitInput,
 *     resetInput: resetInput,
 *     textInput: textInput,
 *     passwordInput: passwordInput,
 *     fileInput: fileInput,
 *     textarea: textarea,
 *     radio: radio,
 *     radio: radio,
 * }}
 *
 * @todo Document every function
 * @todo Implement intialization options for BaseHtml() function
 * @todo Think of "Model" class implementation for all of those "active*" fields
 * @todo checkbox
 * @todo dropDownList
 * @todo listBox
 * @todo checkboxList
 * @todo radioList
 * @todo ul
 * @todo ol
 * @todo ol
 * @todo activeLabel
 * @todo errorSummary
 * @todo error
 * @todo activeInput
 * @todo activeTextInput
 * @todo activeHiddenInput
 * @todo activePasswordInput
 * @todo activeFileInput
 * @todo activeTextarea
 * @todo activeRadio
 * @todo activeCheckbox
 * @todo activeDropDownList
 * @todo activeListBox
 * @todo activeCheckboxList
 * @todo activeRadioList
 * @todo activeListInput
 * @todo renderSelectOptions
 * @todo addCssClass
 * @todo removeCssClass
 * @todo addCssStyle
 * @todo removeCssStyle
 * @todo removeCssStyle
 * @todo cssStyleFromArray
 * @todo cssStyleToArray
 * @todo getAttributeName
 * @todo getAttributeValue
 * @todo getInputName
 * @todo getInputId
 */
function BaseHtml() {
	var settings = {
			charset: 'UTF-8'
		},
		voidElements = {
			'area': 1,
			'base': 1,
			'br': 1,
			'col': 1,
			'command': 1,
			'embed': 1,
			'hr': 1,
			'img': 1,
			'input': 1,
			'keygen': 1,
			'link': 1,
			'meta': 1,
			'param': 1,
			'source': 1,
			'track': 1,
			'wbr': 1
		},
		attributeOrder = [
			'type',
			'id',
			'class',
			'name',
			'value',
			'href',
			'src',
			'action',
			'method',
			'selected',
			'checked',
			'readonly',
			'disabled',
			'multiple',
			'size',
			'maxlength',
			'width',
			'height',
			'rows',
			'cols',
			'alt',
			'title',
			'rel',
			'media'
		],
		functions = {};
	functions.encode = function(content, doubleEncode) {
		if (isUndefined(doubleEncode)) {
			doubleEncode = true;
		}
		return htmlspecialchars(content, ['ENT_QUOTES', 'ENT_SUBSTITUTE'], settings.charset, doubleEncode);
	};
	functions.decode = function(content) {
		return htmlspecialchars_decode(content, 'ENT_QUOTES');
	};
	functions.renderTagAttributes = function(attributes) {
		var name, i;
		if (attributes.length > 1) {
			var sorted = [];
			for (i in attributeOrder) {
				if (attributeOrder.hasOwnProperty(i)) {
					name = attributeOrder[i];
					if (isDefined(attributes[name])) {
						sorted[name] = attributes[name];
					}
				}
			}
			attributes = mergeOptions(sorted, attributes);
		}
		var html = '';
		for (name in attributes) {
			if (attributes.hasOwnProperty(name)) {
				var value = attributes[name];
				if (isBool(value)) {
					if (value) {
						html += ' $name';
					}
				}
				else if (isArray(value) && name === 'data') {
					for (var n in value) {
						if (value.hasOwnProperty(n)) {
							var v = value[n];
							if (isArray(v)) {
								//html += ' '+name+'-'+n+'=\''+Json::encode($v, JSON_HEX_APOS)+'\'';
							}
							else {
								html += ' '+name+'-'+n+'="'+functions.encode(v)+'"';
							}
						}
					}
				}
				else if (value !== null) {
					html += ' '+name+'="'+functions.encode(value)+'"';
				}
			}
		}
		return html;
	};
	functions.tag = function(name, content, options) {
		if (isUndefined(content)) {
			content = '';
		}
		if (isUndefined(options)) {
			options = {};
		}
		var html = '<'+name+functions.renderTagAttributes(options)+'>';
		return isDefined(voidElements[name.toLowerCase()]) ? html : html+content+'</'+name+'>';
	};
	functions.beginTag = function(name, options) {
		if (isUndefined(options)) {
			options = {};
		}
		return '<'+name+functions.renderTagAttributes(options)+'>';
	};
	functions.endTag = function(name) {
		return '</'+name+'>';
	};
	functions.style = function(content, options) {
		if (isUndefined(options)) {
			options = {};
		}
		return functions.tag('style', content, options);
	};
	functions.script = function(content, options) {
		if (isUndefined(options)) {
			options = {};
		}
		return functions.tag('script', content, options);
	};
	functions.cssFile = function(url, options) {
		if (isUndefined(options)) {
			options = {};
		}
		if (isUndefined(options['rel'])) {
			options['rel'] = 'stylesheet';
		}
		options['href'] = url;
		if (isDefined(options['condition'])) {
			var condition = options['condition'];
			delete options['condition'];
			return '<!--[if '+condition+']>'+"\n"+functions.tag('link', '', options)+"\n<![endif]-->";
		}
		else if (isDefined(options['noscript']) && options['noscript'] === true) {
			delete options['noscript'];
			return "<noscript>"+functions.tag('link', '', options)+"</noscript>";
		}
		else {
			return functions.tag('link', '', options);
		}
	};
	functions.jsFile = function(url, options) {
		if (isUndefined(options)) {
			options = {};
		}
		options['src'] = url;
		if (isDefined(options['condition'])) {
			var condition = options['condition'];
			delete options['condition'];
			return '<!--[if '+condition+']>'+"\n"+functions.tag('script', '', options)+"\n<![endif]-->";
		}
		else {
			return functions.tag('script', '', options);
		}
	};
	functions.hiddenInput = function(name, value, options) {
		return functions.input('hidden', name, value, options);
	};
	functions.beginForm = function(action, method, options) {
		if (isUndefined(action)) {
			action = '';
		}
		if (isUndefined(method)) {
			method = 'post';
		}
		if (isUndefined(options)) {
			options = {};
		}
		var hiddenInputs = [],
			pos = strpos(action, '?');
		if (!strcasecmp(method, 'get') && pos !== false) {
			// query parameters in the action are ignored for GET method
			// we use hidden fields to add them back
			var explodedAction = explode('&', substr(action, pos + 1));
			for (var i in explodedAction) {
				if (explodedAction.hasOwnProperty(i)) {
					var pair = explodedAction[i],
						pos1 = strpos(pair, '=');
					if (pos1 !== false) {
						hiddenInputs.push(functions.hiddenInput(
							urldecode(substr(pair, 0, pos1)),
							urldecode(substr(pair, pos1 + 1))
						));
					}
					else {
						hiddenInputs.push(functions.hiddenInput(urldecode(pair), ''));
					}
				}
			}
			action = substr(action, 0, pos);
		}
		options['action'] = action;
		options['method'] = method;
		var form = functions.beginTag('form', options);
		if (!isEmpty(hiddenInputs)) {
			form += "\n"+implode("\n", hiddenInputs);
		}
		return form;
	};
	functions.endForm = function() {
		return '</form>';
	};
	functions.a = function(text, url, options) {
		if (isUndefined(url)) {
			url = null;
		}
		if (isUndefined(options)) {
			options = {};
		}
		if (url !== null) {
			options['href'] = url;
		}
		return functions.tag('a', text, options);
	};
	functions.mailto = function(text, email, options) {
		if (isUndefined(email)) {
			email = null;
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['href'] = 'mailto:'+(email === null ? text : email);
		return functions.tag('a', text, options);
	};
	functions.img = function(src, options) {
		if (isUndefined(options)) {
			options = {};
		}
		options['src'] = src;
		if (isUndefined(options['alt'])) {
			options['alt'] = '';
		}
		return functions.tag('img', '', options);
	};
	functions.label = function(content, _for, options) {
		if (isUndefined(_for)) {
			_for = null;
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['for'] = _for;
		return functions.tag('label', content, options);
	};
	functions.button = function(content, options) {
		if (isUndefined(content)) {
			content = 'Button';
		}
		if (isUndefined(options)) {
			options = {};
		}
		if (isUndefined(options['type'])) {
			options['type'] = 'button';
		}
		return functions.tag('button', content, options);
	};
	functions.submitButton = function(content, options) {
		if (isUndefined(content)) {
			content = 'Submit';
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['type'] = 'submit';
		return functions.button(content, options);
	};
	functions.resetButton = function(content, options) {
		if (isUndefined(content)) {
			content = 'Reset';
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['type'] = 'reset';
		return functions.button(content, options);
	};
	functions.input = function(type, name, value, options) {
		if (isUndefined(name)) {
			name = null;
		}
		if (isUndefined(value)) {
			value = null;
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['type'] = type;
		options['name'] = name;
		options['value'] = value === null ? null : value;
		return functions.tag('input', '', options);
	};
	functions.buttonInput = function(label, options) {
		if (isUndefined(label)) {
			label = 'Button';
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['type'] = 'button';
		options['value'] = label;
		return functions.tag('input', '', options);
	};
	functions.submitInput = function(label, options) {
		if (isUndefined(label)) {
			label = 'Submit';
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['type'] = 'submit';
		options['value'] = label;
		return functions.tag('input', '', options);
	};
	functions.resetInput = function(label, options) {
		if (isUndefined(label)) {
			label = 'Reset';
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['type'] = 'reset';
		options['value'] = label;
		return functions.tag('input', '', options);
	};
	functions.textInput = function(name, value, options) {
		return functions.input('text', name, value, options);
	};
	functions.passwordInput = function(name, value, options) {
		return functions.input('password', name, value, options);
	};
	functions.fileInput = function(name, value, options) {
		return functions.input('file', name, value, options);
	};
	functions.textarea = function(name, value, options) {
		if (isUndefined(name)) {
			name = null;
		}
		if (isUndefined(value)) {
			value = '';
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['name'] = name;
		return functions.tag('textarea', functions.encode(value), options);
	};
	functions.radio = function(name, checked , options) {
		if (isUndefined(name)) {
			name = null;
		}
		if (isUndefined(checked )) {
			checked  = false;
		}
		if (isUndefined(options)) {
			options = {};
		}
		options['checked'] = Boolean(checked);
		var value = isDefined(options['value']) ? options['value'] : '1', hidden;
		if (isDefined(options['uncheck'])) {
			// add a hidden field so that if the radio button is not selected, it still submits a value
			hidden = functions.hiddenInput(name, options['uncheck']);
			delete options['uncheck'];
		}
		else {
			hidden = '';
		}
		if (isDefined(options['label'])) {
			var label = options['label'],
				labelOptions = isDefined(options['labelOptions']) ? options['labelOptions'] : {};
			delete options['label'];
			delete options['labelOptions'];
			var content = functions.label(
				functions.input('radio', name, value, options)+' '+label,
				null,
				labelOptions
			);
			return hidden+content;
		}
		else {
			return hidden+functions.input('radio', name, value, options);
		}
	};
	return functions;
}