/*
This file is part of Ext JS 4.2

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-05-16 14:36:50 (f9be68accb407158ba2b1be2c226a6ce1f649314)
*/
// @tag core
/**
 * A template class that supports advanced functionality like:
 *
 * - Autofilling arrays using templates and sub-templates
 * - Conditional processing with basic comparison operators
 * - Basic math function support
 * - Execute arbitrary inline code with special built-in template variables
 * - Custom member functions
 * - Many special tags and built-in operators that aren't defined as part of the API, but are supported in the templates that can be created
 *
 * XTemplate provides the templating mechanism built into {@link Ext.view.View}.
 *
 * The {@link Ext.Template} describes the acceptable parameters to pass to the constructor. The following examples
 * demonstrate all of the supported features.
 *
 * # Sample Data
 *
 * This is the data object used for reference in each code example:
 *
 *     var data = {
 *         name: 'Don Griffin',
 *         title: 'Senior Technomage',
 *         company: 'Sencha Inc.',
 *         drinks: ['Coffee', 'Water', 'More Coffee'],
 *         kids: [
 *             { name: 'Aubrey',  age: 17 },
 *             { name: 'Joshua',  age: 13 },
 *             { name: 'Cale',    age: 10 },
 *             { name: 'Nikol',   age: 5 },
 *             { name: 'Solomon', age: 0 }
 *         ]
 *     };
 *
 * # Auto filling of arrays
 *
 * The **tpl** tag and the **for** operator are used to process the provided data object:
 *
 * - If the value specified in for is an array, it will auto-fill, repeating the template block inside the tpl
 *   tag for each item in the array.
 * - If for="." is specified, the data object provided is examined.
 * - If between="..." is specified, the provided value will be inserted between the items.
 *   This is also supported in the "foreach" looping template.
 * - While processing an array, the special variable {#} will provide the current array index + 1 (starts at 1, not 0).
 *
 * Examples:
 *
 *     <tpl for=".">...</tpl>       // loop through array at root node
 *     <tpl for="foo">...</tpl>     // loop through array at foo node
 *     <tpl for="foo.bar">...</tpl> // loop through array at foo.bar node
 *     <tpl for="." between=",">...</tpl> // loop through array at root node and insert ',' between each item
 *
 * Using the sample data above:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Kids: ',
 *         '<tpl for=".">',       // process the data.kids node
 *             '<p>{#}. {name}</p>',  // use current array index to autonumber
 *         '</tpl></p>'
 *     );
 *     tpl.overwrite(panel.body, data.kids); // pass the kids property of the data object
 *
 * An example illustrating how the **for** property can be leveraged to access specified members of the provided data
 * object to populate the template:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Title: {title}</p>',
 *         '<p>Company: {company}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',     // interrogate the kids property within the data
 *             '<p>{name}</p>',
 *         '</tpl></p>'
 *     );
 *     tpl.overwrite(panel.body, data);  // pass the root node of the data object
 *
 * Flat arrays that contain values (and not objects) can be auto-rendered using the special **`{.}`** variable inside a
 * loop. This variable will represent the value of the array at the current index:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>{name}\'s favorite beverages:</p>',
 *         '<tpl for="drinks">',
 *             '<div> - {.}</div>',
 *         '</tpl>'
 *     );
 *     tpl.overwrite(panel.body, data);
 *
 * When processing a sub-template, for example while looping through a child array, you can access the parent object's
 * members via the **parent** object:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '<tpl if="age &gt; 1">',
 *                 '<p>{name}</p>',
 *                 '<p>Dad: {parent.name}</p>',
 *             '</tpl>',
 *         '</tpl></p>'
 *     );
 *     tpl.overwrite(panel.body, data);
 *     
 * The **foreach** operator is used to loop over an object's properties.  The following
 * example demonstrates looping over the main data object's properties:
 * 
 *     var tpl = new Ext.XTemplate(
 *         '<dl>',
 *             '<tpl foreach=".">',
 *                 '<dt>{$}</dt>', // the special **`{$}`** variable contains the property name
 *                 '<dd>{.}</dd>', // within the loop, the **`{.}`** variable is set to the property value
 *             '</tpl>',
 *         '</dl>'
 *     );
 *     tpl.overwrite(panel.body, data);
 *
 * # Conditional processing with basic comparison operators
 *
 * The **tpl** tag and the **if** operator are used to provide conditional checks for deciding whether or not to render
 * specific parts of the template.
 *
 * Using the sample data above:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '<tpl if="age &gt; 1">',
 *                 '<p>{name}</p>',
 *             '</tpl>',
 *         '</tpl></p>'
 *     );
 *     tpl.overwrite(panel.body, data);
 *
 * More advanced conditionals are also supported:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '<p>{name} is a ',
 *             '<tpl if="age &gt;= 13">',
 *                 '<p>teenager</p>',
 *             '<tpl elseif="age &gt;= 2">',
 *                 '<p>kid</p>',
 *             '<tpl else>',
 *                 '<p>baby</p>',
 *             '</tpl>',
 *         '</tpl></p>'
 *     );
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '<p>{name} is a ',
 *             '<tpl switch="name">',
 *                 '<tpl case="Aubrey" case="Nikol">',
 *                     '<p>girl</p>',
 *                 '<tpl default>',
 *                     '<p>boy</p>',
 *             '</tpl>',
 *         '</tpl></p>'
 *     );
 *
 * A `break` is implied between each case and default, however, multiple cases can be listed
 * in a single &lt;tpl&gt; tag.
 *
 * # Using double quotes
 *
 * Examples:
 *
 *     var tpl = new Ext.XTemplate(
 *         "<tpl if='age &gt; 1 && age &lt; 10'>Child</tpl>",
 *         "<tpl if='age &gt;= 10 && age &lt; 18'>Teenager</tpl>",
 *         "<tpl if='this.isGirl(name)'>...</tpl>",
 *         '<tpl if="id == \'download\'">...</tpl>',
 *         "<tpl if='needsIcon'><img src='{icon}' class='{iconCls}'/></tpl>",
 *         "<tpl if='name == \"Don\"'>Hello</tpl>"
 *     );
 *
 * # Basic math support
 *
 * The following basic math operators may be applied directly on numeric data values:
 *
 *     + - * /
 *
 * For example:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '<tpl if="age &gt; 1">',  // <-- Note that the > is encoded
 *                 '<p>{#}: {name}</p>',  // <-- Auto-number each item
 *                 '<p>In 5 Years: {age+5}</p>',  // <-- Basic math
 *                 '<p>Dad: {parent.name}</p>',
 *             '</tpl>',
 *         '</tpl></p>'
 *     );
 *     tpl.overwrite(panel.body, data);
 *
 * # Execute arbitrary inline code with special built-in template variables
 *
 * Anything between `{[ ... ]}` is considered code to be executed in the scope of the template.
 * The expression is evaluated and the result is included in the generated result. There are
 * some special variables available in that code:
 *
 * - **out**: The output array into which the template is being appended (using `push` to later
 *   `join`).
 * - **values**: The values in the current scope. If you are using scope changing sub-templates,
 *   you can change what values is.
 * - **parent**: The scope (values) of the ancestor template.
 * - **xindex**: If you are in a "for" or "foreach" looping template, the index of the loop you are in (1-based).
 * - **xcount**: If you are in a "for" looping template, the total length of the array you are looping.
 * - **xkey**: If you are in a "foreach" looping template, the key of the current property
 * being examined.
 *
 * This example demonstrates basic row striping using an inline code block and the xindex variable:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Company: {[values.company.toUpperCase() + ", " + values.title]}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '<div class="{[xindex % 2 === 0 ? "even" : "odd"]}">',
 *             '{name}',
 *             '</div>',
 *         '</tpl></p>'
 *      );
 *
 * Any code contained in "verbatim" blocks (using "{% ... %}") will be inserted directly in
 * the generated code for the template. These blocks are not included in the output. This
 * can be used for simple things like break/continue in a loop, or control structures or
 * method calls (when they don't produce output). The `this` references the template instance.
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Company: {[values.company.toUpperCase() + ", " + values.title]}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '{% if (xindex % 2 === 0) continue; %}',
 *             '{name}',
 *             '{% if (xindex > 100) break; %}',
 *             '</div>',
 *         '</tpl></p>'
 *      );
 *
 * # Template member functions
 *
 * One or more member functions can be specified in a configuration object passed into the XTemplate constructor for
 * more complex processing:
 *
 *     var tpl = new Ext.XTemplate(
 *         '<p>Name: {name}</p>',
 *         '<p>Kids: ',
 *         '<tpl for="kids">',
 *             '<tpl if="this.isGirl(name)">',
 *                 '<p>Girl: {name} - {age}</p>',
 *             '<tpl else>',
 *                 '<p>Boy: {name} - {age}</p>',
 *             '</tpl>',
 *             '<tpl if="this.isBaby(age)">',
 *                 '<p>{name} is a baby!</p>',
 *             '</tpl>',
 *         '</tpl></p>',
 *         {
 *             // XTemplate configuration:
 *             disableFormats: true,
 *             // member functions:
 *             isGirl: function(name){
 *                return name == 'Aubrey' || name == 'Nikol';
 *             },
 *             isBaby: function(age){
 *                return age < 1;
 *             }
 *         }
 *     );
 *     tpl.overwrite(panel.body, data);
 */
Ext.define('Ext.XTemplate', {
    extend: 'Ext.Template',

    requires: 'Ext.XTemplateCompiler',

    /**
     * @private
     */
    emptyObj: {},

    /**
     * @cfg {Boolean} compiled
     * Only applies to {@link Ext.Template}, XTemplates are compiled automatically on the
     * first call to {@link #apply} or {@link #applyOut}.
     * @hide
     */

    /**
     * @cfg {String/Array} definitions
     * Optional. A statement, or array of statements which set up `var`s which may then
     * be accessed within the scope of the generated function.
     */

    apply: function(values, parent) {
        return this.applyOut(values, [], parent).join('');
    },

    applyOut: function(values, out, parent) {
        var me = this,
            compiler;

        if (!me.fn) {
            compiler = new Ext.XTemplateCompiler({
                useFormat: me.disableFormats !== true,
                definitions: me.definitions
            });

            me.fn = compiler.compile(me.html);
        }

        try {
            me.fn(out, values, parent || me.emptyObj, 1, 1);
        } catch (e) {
            //<debug>
            Ext.log('Error: ' + e.message);
            //</debug>
        }

        return out;
    },

    /**
     * Does nothing. XTemplates are compiled automatically, so this function simply returns this.
     * @return {Ext.XTemplate} this
     */
    compile: function() {
        return this;
    },

    statics: {
        /**
         * Gets an `XTemplate` from an object (an instance of an {@link Ext#define}'d class).
         * Many times, templates are configured high in the class hierarchy and are to be
         * shared by all classes that derive from that base. To further complicate matters,
         * these templates are seldom actual instances but are rather configurations. For
         * example:
         *
         *      Ext.define('MyApp.Class', {
         *          extraCls: 'extra-class',
         *
         *          someTpl: [
         *              '<div class="{%this.emitClass(out)%}"></div>',
         *          {
         *              // Member fn - outputs the owing class's extra CSS class
         *              emitClass: function(out) {
         *                  out.push(this.owner.extraCls);
         *              }
         *          }]
         *      });
         *
         * The goal being to share that template definition with all instances and even
         * instances of derived classes, until `someTpl` is overridden. This method will
         * "upgrade" these configurations to be real `XTemplate` instances *in place* (to
         * avoid creating one instance per object).
         *
         * The resulting XTemplate will have an `owner` reference injected which refers back
         * to the owning object whether that is an object which has an *own instance*, or a
         * class prototype. Through this link, XTemplate member functions will be able to access
         * prototype properties of its owning class.
         *
         * @param {Object} instance The object from which to get the `XTemplate` (must be
         * an instance of an {@link Ext#define}'d class).
         * @param {String} name The name of the property by which to get the `XTemplate`.
         * @return {Ext.XTemplate} The `XTemplate` instance or null if not found.
         * @protected
         * @static
         */
        getTpl: function (instance, name) {
            var tpl = instance[name], // go for it! 99% of the time we will get it!
                owner;

            if (tpl && !tpl.isTemplate) { // tpl is just a configuration (not an instance)
                // create the template instance from the configuration:
                tpl = Ext.ClassManager.dynInstantiate('Ext.XTemplate', tpl);

                // and replace the reference with the new instance:
                if (instance.hasOwnProperty(name)) { // the tpl is on the instance
                    owner = instance;
                } else { // must be somewhere in the prototype chain
                    for (owner = instance.self.prototype; owner && !owner.hasOwnProperty(name); owner = owner.superclass) {
                    }
                }
                owner[name] = tpl;
                tpl.owner = owner;
            }
            // else !tpl (no such tpl) or the tpl is an instance already... either way, tpl
            // is ready to return

            return tpl || null;
        }
    }
});
