Java example source code file (base.js)

This example Java source code file (base.js) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

array, learn, regexp, run, this, todomvc, xmlhttprequest

The base.js Java example source code

/*
 *
 *  * Copyright 2015 Skymind,Inc.
 *  *
 *  *    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.
 *
 */

/* global _ */
(function () {
	'use strict';

	/* jshint ignore:start */
	// Underscore's Template Module
	// Courtesy of underscorejs.org
	var _ = (function (_) {
		_.defaults = function (object) {
			if (!object) {
				return object;
			}
			for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {
				var iterable = arguments[argsIndex];
				if (iterable) {
					for (var key in iterable) {
						if (object[key] == null) {
							object[key] = iterable[key];
						}
					}
				}
			}
			return object;
		};

		// By default, Underscore uses ERB-style template delimiters, change the
		// following template settings to use alternative delimiters.
		_.templateSettings = {
			evaluate    : /<%([\s\S]+?)%>/g,
			interpolate : /<%=([\s\S]+?)%>/g,
			escape      : /<%-([\s\S]+?)%>/g
		};

		// When customizing `templateSettings`, if you don't want to define an
		// interpolation, evaluation or escaping regex, we need one that is
		// guaranteed not to match.
		var noMatch = /(.)^/;

		// Certain characters need to be escaped so that they can be put into a
		// string literal.
		var escapes = {
			"'":      "'",
			'\\':     '\\',
			'\r':     'r',
			'\n':     'n',
			'\t':     't',
			'\u2028': 'u2028',
			'\u2029': 'u2029'
		};

		var escaper = /\\|'|\r|\n|\t|\u2028|\u2029/g;

		// JavaScript micro-templating, similar to John Resig's implementation.
		// Underscore templating handles arbitrary delimiters, preserves whitespace,
		// and correctly escapes quotes within interpolated code.
		_.template = function(text, data, settings) {
			var render;
			settings = _.defaults({}, settings, _.templateSettings);

			// Combine delimiters into one regular expression via alternation.
			var matcher = new RegExp([
				(settings.escape || noMatch).source,
				(settings.interpolate || noMatch).source,
				(settings.evaluate || noMatch).source
			].join('|') + '|$', 'g');

			// Compile the template source, escaping string literals appropriately.
			var index = 0;
			var source = "__p+='";
			text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
				source += text.slice(index, offset)
					.replace(escaper, function(match) { return '\\' + escapes[match]; });

				if (escape) {
					source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
				}
				if (interpolate) {
					source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
				}
				if (evaluate) {
					source += "';\n" + evaluate + "\n__p+='";
				}
				index = offset + match.length;
				return match;
			});
			source += "';\n";

			// If a variable is not specified, place data values in local scope.
			if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';

			source = "var __t,__p='',__j=Array.prototype.join," +
				"print=function(){__p+=__j.call(arguments,'');};\n" +
				source + "return __p;\n";

			try {
				render = new Function(settings.variable || 'obj', '_', source);
			} catch (e) {
				e.source = source;
				throw e;
			}

			if (data) return render(data, _);
			var template = function(data) {
				return render.call(this, data, _);
			};

			// Provide the compiled function source as a convenience for precompilation.
			template.source = 'function(' + (settings.variable || 'obj') + '){\n' + source + '}';

			return template;
		};

		return _;
	})({});

	if (location.hostname === 'todomvc.com') {
		window._gaq = [['_setAccount','UA-31081062-1'],['_trackPageview']];(function(d,t){var g=d.createElement(t),s=d.getElementsByTagName(t)[0];g.src='//www.google-analytics.com/ga.js';s.parentNode.insertBefore(g,s)}(document,'script'));
	}
	/* jshint ignore:end */

	function redirect() {
		if (location.hostname === 'tastejs.github.io') {
			location.href = location.href.replace('tastejs.github.io/todomvc', 'todomvc.com');
		}
	}

	function findRoot() {
		var base = location.href.indexOf('examples/');
		return location.href.substr(0, base);
	}

	function getFile(file, callback) {
		if (!location.host) {
			return console.info('Miss the info bar? Run TodoMVC from a server to avoid a cross-origin error.');
		}

		var xhr = new XMLHttpRequest();

		xhr.open('GET', findRoot() + file, true);
		xhr.send();

		xhr.onload = function () {
			if (xhr.status === 200 && callback) {
				callback(xhr.responseText);
			}
		};
	}

	function Learn(learnJSON, config) {
		if (!(this instanceof Learn)) {
			return new Learn(learnJSON, config);
		}

		var template, framework;

		if (typeof learnJSON !== 'object') {
			try {
				learnJSON = JSON.parse(learnJSON);
			} catch (e) {
				return;
			}
		}

		if (config) {
			template = config.template;
			framework = config.framework;
		}

		if (!template && learnJSON.templates) {
			template = learnJSON.templates.todomvc;
		}

		if (!framework && document.querySelector('[data-framework]')) {
			framework = document.querySelector('[data-framework]').dataset.framework;
		}

		this.template = template;

		if (learnJSON.backend) {
			this.frameworkJSON = learnJSON.backend;
			this.frameworkJSON.issueLabel = framework;
			this.append({
				backend: true
			});
		} else if (learnJSON[framework]) {
			this.frameworkJSON = learnJSON[framework];
			this.frameworkJSON.issueLabel = framework;
			this.append();
		}

		this.fetchIssueCount();
	}

	Learn.prototype.append = function (opts) {
		var aside = document.createElement('aside');
		aside.innerHTML = _.template(this.template, this.frameworkJSON);
		aside.className = 'learn';

		if (opts && opts.backend) {
			// Remove demo link
			var sourceLinks = aside.querySelector('.source-links');
			var heading = sourceLinks.firstElementChild;
			var sourceLink = sourceLinks.lastElementChild;
			// Correct link path
			var href = sourceLink.getAttribute('href');
			sourceLink.setAttribute('href', href.substr(href.lastIndexOf('http')));
			sourceLinks.innerHTML = heading.outerHTML + sourceLink.outerHTML;
		} else {
			// Localize demo links
			var demoLinks = aside.querySelectorAll('.demo-link');
			Array.prototype.forEach.call(demoLinks, function (demoLink) {
				if (demoLink.getAttribute('href').substr(0, 4) !== 'http') {
					demoLink.setAttribute('href', findRoot() + demoLink.getAttribute('href'));
				}
			});
		}

		document.body.className = (document.body.className + ' learn-bar').trim();
		document.body.insertAdjacentHTML('afterBegin', aside.outerHTML);
	};

	Learn.prototype.fetchIssueCount = function () {
		var issueLink = document.getElementById('issue-count-link');
		if (issueLink) {
			var url = issueLink.href.replace('https://github.com', 'https://api.github.com/repos');
			var xhr = new XMLHttpRequest();
			xhr.open('GET', url, true);
			xhr.onload = function (e) {
				var parsedResponse = JSON.parse(e.target.responseText);
				if (parsedResponse instanceof Array) {
					var count = parsedResponse.length;
					if (count !== 0) {
						issueLink.innerHTML = 'This app has ' + count + ' open issues';
						document.getElementById('issue-count').style.display = 'inline';
					}
				}
			};
			xhr.send();
		}
	};

	redirect();
	//getFile('learn.json', Learn);
})();