marko/runtime/helpers.js

357 lines
10 KiB
JavaScript

/*
* Copyright 2011 eBay Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
var escapeXml = require('raptor-util/escapeXml');
var escapeXmlAttr = escapeXml.attr;
var runtime = require('./'); // Circular dependency, but that is okay
var attr = require('raptor-util/attr');
var attrs = require('raptor-util/attrs');
var isArray = Array.isArray;
var STYLE_ATTR = 'style';
var CLASS_ATTR = 'class';
function notEmpty(o) {
if (o == null) {
return false;
} else if (Array.isArray(o)) {
return !!o.length;
} else if (o === '') {
return false;
}
return true;
}
function classListArray(classList) {
var classNames = [];
for (var i=0, len=classList.length; i<len; i++) {
var cur = classList[i];
if (cur) {
classNames.push(cur);
}
}
return classNames.join(' ');
}
function createDeferredRenderer(handler) {
function deferredRenderer(input, out) {
deferredRenderer.renderer(input, out);
}
// This is the initial function that will do the rendering. We replace
// the renderer with the actual renderer func on the first render
deferredRenderer.renderer = function(input, out) {
var rendererFunc = handler.renderer || handler.render;
if (typeof rendererFunc !== 'function') {
throw new Error('Invalid tag handler: ' + handler);
}
// Use the actual renderer from now on
deferredRenderer.renderer = rendererFunc;
rendererFunc(input, out);
};
return deferredRenderer;
}
function resolveRenderer(handler) {
var renderer = handler.renderer;
if (renderer) {
return renderer;
}
if (typeof handler === 'function') {
return handler;
}
if (typeof (renderer = handler.render) === 'function') {
return renderer;
}
// If the user code has a circular function then the renderer function
// may not be available on the module. Since we can't get a reference
// to the actual renderer(input, out) function right now we lazily
// try to get access to it later.
return createDeferredRenderer(handler);
}
module.exports = {
/**
* Internal helper method to prevent null/undefined from being written out
* when writing text that resolves to null/undefined
* @private
*/
s: function(str) {
return (str == null) ? '' : str;
},
/**
* Internal helper method to handle loops with a status variable
* @private
*/
fv: function (array, callback) {
if (!array) {
return;
}
if (!array.forEach) {
array = [array];
}
var i = 0;
var len = array.length;
var loopStatus = {
getLength: function () {
return len;
},
isLast: function () {
return i === len - 1;
},
isFirst: function () {
return i === 0;
},
getIndex: function () {
return i;
}
};
for (; i < len; i++) {
var o = array[i];
callback(o, loopStatus);
}
},
/**
* Internal helper method to handle loops without a status variable
* @private
*/
f: function forEach(array, callback) {
if (isArray(array)) {
for (var i=0; i<array.length; i++) {
callback(array[i]);
}
} else if (typeof array === 'function') {
// Also allow the first argument to be a custom iterator function
array(callback);
}
},
/**
* Internal helper method for looping over the properties of any object
* @private
*/
fp: function (o, func) {
if (!o) {
return;
}
for (var k in o) {
if (o.hasOwnProperty(k)) {
func(k, o[k]);
}
}
},
/**
* Internal method to check if an object/array is empty
* @private
*/
e: function (o) {
return !notEmpty(o);
},
/**
* Internal method to check if an object/array is not empty
* @private
*/
ne: notEmpty,
/**
* Internal method to escape special XML characters
* @private
*/
x: escapeXml,
/**
* Internal method to escape special XML characters within an attribute
* @private
*/
xa: escapeXmlAttr,
/**
* Internal method to render a single HTML attribute
* @private
*/
a: attr,
/**
* Internal method to render multiple HTML attributes based on the properties of an object
* @private
*/
as: attrs,
/**
* Internal helper method to handle the "style" attribute. The value can either
* be a string or an object with style propertes. For example:
*
* sa('color: red; font-weight: bold') ==> ' style="color: red; font-weight: bold"'
* sa({color: 'red', 'font-weight': 'bold'}) ==> ' style="color: red; font-weight: bold"'
*/
sa: function(style) {
if (!style) {
return '';
}
if (typeof style === 'string') {
return attr(STYLE_ATTR, style, false);
} else if (typeof style === 'object') {
var parts = [];
for (var name in style) {
if (style.hasOwnProperty(name)) {
var value = style[name];
if (value) {
parts.push(name + ':' + value);
}
}
}
return parts ? attr(STYLE_ATTR, parts.join(';'), false) : '';
} else {
return '';
}
},
/**
* Internal helper method to handle the "class" attribute. The value can either
* be a string, an array or an object. For example:
*
* ca('foo bar') ==> ' class="foo bar"'
* ca({foo: true, bar: false, baz: true}) ==> ' class="foo baz"'
* ca(['foo', 'bar']) ==> ' class="foo bar"'
*/
ca: function(classNames) {
if (!classNames) {
return '';
}
if (typeof classNames === 'string') {
return attr(CLASS_ATTR, classNames, false);
} else if (isArray(classNames)) {
return attr(CLASS_ATTR, classListArray(classNames), false);
} else if (typeof classNames === 'object') {
var classList = [];
for (var name in classNames) {
if (classNames.hasOwnProperty(name)) {
var value = classNames[name];
if (value) {
classList.push(name);
}
}
}
return attr(CLASS_ATTR, classListArray(classList), false);
} else {
return '';
}
},
/**
* Loads a template
*/
l: function(path) {
if (typeof path === 'string') {
return runtime.load(path);
} else {
// Assume it is already a pre-loaded template
return path;
}
},
// ----------------------------------
// The helpers listed below require an out
// ----------------------------------
/**
* Invoke a tag handler render function
*/
t: function (renderer, targetProperty, isRepeated, hasNestedTags) {
if (renderer) {
renderer = resolveRenderer(renderer);
}
if (targetProperty || hasNestedTags) {
return function(input, out, parent, renderBody) {
// Handle nested tags
if (renderBody) {
renderBody(out, input);
}
if (targetProperty) {
// If we are nested tag then we do not have a renderer
if (isRepeated) {
var existingArray = parent[targetProperty];
if (existingArray) {
existingArray.push(input);
} else {
parent[targetProperty] = [input];
}
} else {
parent[targetProperty] = input;
}
} else {
// We are a tag with nested tags, but we have already found
// our nested tags by rendering the body
renderer(input, out);
}
};
} else {
return renderer;
}
},
/**
* Internal method to handle includes/partials
* @private
*/
i: function(out, template, data) {
if (!template) {
return;
}
if (typeof template.render === 'function') {
template.render(data, out);
} else {
throw new Error('Invalid template: ' + template);
}
return this;
},
/**
* Merges object properties
* @param {[type]} object [description]
* @param {[type]} source [description]
* @return {[type]} [description]
*/
m: function(into, source) {
for (var k in source) {
if (source.hasOwnProperty(k) && !into.hasOwnProperty(k)) {
into[k] = source[k];
}
}
return into;
},
/**
* classList(a, b, c, ...)
* Joines a list of class names with spaces. Empty class names are omitted.
*
* classList('a', undefined, 'b') --> 'a b'
*
*/
cl: function() {
return classListArray(arguments);
}
};