/*
This file is part of Ext JS 3.4

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: 2013-04-03 15:07:25
*/
/**
 * @class Ext.data.DataProxy
 * @extends Ext.util.Observable
 * <p>Abstract base class for implementations which provide retrieval of unformatted data objects.
 * This class is intended to be extended and should not be created directly. For existing implementations,
 * see {@link Ext.data.DirectProxy}, {@link Ext.data.HttpProxy}, {@link Ext.data.ScriptTagProxy} and
 * {@link Ext.data.MemoryProxy}.</p>
 * <p>DataProxy implementations are usually used in conjunction with an implementation of {@link Ext.data.DataReader}
 * (of the appropriate type which knows how to parse the data object) to provide a block of
 * {@link Ext.data.Records} to an {@link Ext.data.Store}.</p>
 * <p>The parameter to a DataProxy constructor may be an {@link Ext.data.Connection} or can also be the
 * config object to an {@link Ext.data.Connection}.</p>
 * <p>Custom implementations must implement either the <code><b>doRequest</b></code> method (preferred) or the
 * <code>load</code> method (deprecated). See
 * {@link Ext.data.HttpProxy}.{@link Ext.data.HttpProxy#doRequest doRequest} or
 * {@link Ext.data.HttpProxy}.{@link Ext.data.HttpProxy#load load} for additional details.</p>
 * <p><b><u>Example 1</u></b></p>
 * <pre><code>
proxy: new Ext.data.ScriptTagProxy({
    {@link Ext.data.Connection#url url}: 'http://extjs.com/forum/topics-remote.php'
}),
 * </code></pre>
 * <p><b><u>Example 2</u></b></p>
 * <pre><code>
proxy : new Ext.data.HttpProxy({
    {@link Ext.data.Connection#method method}: 'GET',
    {@link Ext.data.HttpProxy#prettyUrls prettyUrls}: false,
    {@link Ext.data.Connection#url url}: 'local/default.php', // see options parameter for {@link Ext.Ajax#request}
    {@link #api}: {
        // all actions except the following will use above url
        create  : 'local/new.php',
        update  : 'local/update.php'
    }
}),
 * </code></pre>
 * <p>And <b>new in Ext version 3</b>, attach centralized event-listeners upon the DataProxy class itself!  This is a great place
 * to implement a <i>messaging system</i> to centralize your application's user-feedback and error-handling.</p>
 * <pre><code>
// Listen to all "beforewrite" event fired by all proxies.
Ext.data.DataProxy.on('beforewrite', function(proxy, action) {
    console.log('beforewrite: ', action);
});

// Listen to "write" event fired by all proxies
Ext.data.DataProxy.on('write', function(proxy, action, data, res, rs) {
    console.info('write: ', action);
});

// Listen to "exception" event fired by all proxies
Ext.data.DataProxy.on('exception', function(proxy, type, action, exception) {
    console.error(type + action + ' exception);
});
 * </code></pre>
 * <b>Note:</b> These three events are all fired with the signature of the corresponding <i>DataProxy instance</i> event {@link #beforewrite beforewrite}, {@link #write write} and {@link #exception exception}.
 */
Ext.data.DataProxy = function(conn){
    // make sure we have a config object here to support ux proxies.
    // All proxies should now send config into superclass constructor.
    conn = conn || {};

    // This line caused a bug when people use custom Connection object having its own request method.
    // http://extjs.com/forum/showthread.php?t=67194.  Have to set DataProxy config
    //Ext.applyIf(this, conn);

    this.api     = conn.api;
    this.url     = conn.url;
    this.restful = conn.restful;
    this.listeners = conn.listeners;

    // deprecated
    this.prettyUrls = conn.prettyUrls;

    /**
     * @cfg {Object} api
     * Specific urls to call on CRUD action methods "read", "create", "update" and "destroy".
     * Defaults to:<pre><code>
api: {
    read    : undefined,
    create  : undefined,
    update  : undefined,
    destroy : undefined
}
     * </code></pre>
     * <p>The url is built based upon the action being executed <tt>[load|create|save|destroy]</tt>
     * using the commensurate <tt>{@link #api}</tt> property, or if undefined default to the
     * configured {@link Ext.data.Store}.{@link Ext.data.Store#url url}.</p><br>
     * <p>For example:</p>
     * <pre><code>
api: {
    load :    '/controller/load',
    create :  '/controller/new',  // Server MUST return idProperty of new record
    save :    '/controller/update',
    destroy : '/controller/destroy_action'
}

// Alternatively, one can use the object-form to specify each API-action
api: {
    load: {url: 'read.php', method: 'GET'},
    create: 'create.php',
    destroy: 'destroy.php',
    save: 'update.php'
}
     * </code></pre>
     * <p>If the specific URL for a given CRUD action is undefined, the CRUD action request
     * will be directed to the configured <tt>{@link Ext.data.Connection#url url}</tt>.</p>
     * <br><p><b>Note</b>: To modify the URL for an action dynamically the appropriate API
     * property should be modified before the action is requested using the corresponding before
     * action event.  For example to modify the URL associated with the load action:
     * <pre><code>
// modify the url for the action
myStore.on({
    beforeload: {
        fn: function (store, options) {
            // use <tt>{@link Ext.data.HttpProxy#setUrl setUrl}</tt> to change the URL for *just* this request.
            store.proxy.setUrl('changed1.php');

            // set optional second parameter to true to make this URL change
            // permanent, applying this URL for all subsequent requests.
            store.proxy.setUrl('changed1.php', true);

            // Altering the proxy API should be done using the public
            // method <tt>{@link Ext.data.DataProxy#setApi setApi}</tt>.
            store.proxy.setApi('read', 'changed2.php');

            // Or set the entire API with a config-object.
            // When using the config-object option, you must redefine the <b>entire</b>
            // API -- not just a specific action of it.
            store.proxy.setApi({
                read    : 'changed_read.php',
                create  : 'changed_create.php',
                update  : 'changed_update.php',
                destroy : 'changed_destroy.php'
            });
        }
    }
});
     * </code></pre>
     * </p>
     */

    this.addEvents(
        /**
         * @event exception
         * <p>Fires if an exception occurs in the Proxy during a remote request. This event is relayed
         * through a corresponding {@link Ext.data.Store}.{@link Ext.data.Store#exception exception},
         * so any Store instance may observe this event.</p>
         * <p>In addition to being fired through the DataProxy instance that raised the event, this event is also fired
         * through the Ext.data.DataProxy <i>class</i> to allow for centralized processing of exception events from <b>all</b>
         * DataProxies by attaching a listener to the Ext.data.DataProxy class itself.</p>
         * <p>This event can be fired for one of two reasons:</p>
         * <div class="mdetail-params"><ul>
         * <li>remote-request <b>failed</b> : <div class="sub-desc">
         * The server did not return status === 200.
         * </div></li>
         * <li>remote-request <b>succeeded</b> : <div class="sub-desc">
         * The remote-request succeeded but the reader could not read the response.
         * This means the server returned data, but the configured Reader threw an
         * error while reading the response.  In this case, this event will be
         * raised and the caught error will be passed along into this event.
         * </div></li>
         * </ul></div>
         * <br><p>This event fires with two different contexts based upon the 2nd
         * parameter <tt>type [remote|response]</tt>.  The first four parameters
         * are identical between the two contexts -- only the final two parameters
         * differ.</p>
         * @param {DataProxy} this The proxy that sent the request
         * @param {String} type
         * <p>The value of this parameter will be either <tt>'response'</tt> or <tt>'remote'</tt>.</p>
         * <div class="mdetail-params"><ul>
         * <li><b><tt>'response'</tt></b> : <div class="sub-desc">
         * <p>An <b>invalid</b> response from the server was returned: either 404,
         * 500 or the response meta-data does not match that defined in the DataReader
         * (e.g.: root, idProperty, successProperty).</p>
         * </div></li>
         * <li><b><tt>'remote'</tt></b> : <div class="sub-desc">
         * <p>A <b>valid</b> response was returned from the server having
         * successProperty === false.  This response might contain an error-message
         * sent from the server.  For example, the user may have failed
         * authentication/authorization or a database validation error occurred.</p>
         * </div></li>
         * </ul></div>
         * @param {String} action Name of the action (see {@link Ext.data.Api#actions}.
         * @param {Object} options The options for the action that were specified in the {@link #request}.
         * @param {Object} response
         * <p>The value of this parameter depends on the value of the <code>type</code> parameter:</p>
         * <div class="mdetail-params"><ul>
         * <li><b><tt>'response'</tt></b> : <div class="sub-desc">
         * <p>The raw browser response object (e.g.: XMLHttpRequest)</p>
         * </div></li>
         * <li><b><tt>'remote'</tt></b> : <div class="sub-desc">
         * <p>The decoded response object sent from the server.</p>
         * </div></li>
         * </ul></div>
         * @param {Mixed} arg
         * <p>The type and value of this parameter depends on the value of the <code>type</code> parameter:</p>
         * <div class="mdetail-params"><ul>
         * <li><b><tt>'response'</tt></b> : Error<div class="sub-desc">
         * <p>The JavaScript Error object caught if the configured Reader could not read the data.
         * If the remote request returns success===false, this parameter will be null.</p>
         * </div></li>
         * <li><b><tt>'remote'</tt></b> : Record/Record[]<div class="sub-desc">
         * <p>This parameter will only exist if the <tt>action</tt> was a <b>write</b> action
         * (Ext.data.Api.actions.create|update|destroy).</p>
         * </div></li>
         * </ul></div>
         */
        'exception',
        /**
         * @event beforeload
         * Fires before a request to retrieve a data object.
         * @param {DataProxy} this The proxy for the request
         * @param {Object} params The params object passed to the {@link #request} function
         */
        'beforeload',
        /**
         * @event load
         * Fires before the load method's callback is called.
         * @param {DataProxy} this The proxy for the request
         * @param {Object} o The request transaction object
         * @param {Object} options The callback's <tt>options</tt> property as passed to the {@link #request} function
         */
        'load',
        /**
         * @event loadexception
         * <p>This event is <b>deprecated</b>.  The signature of the loadexception event
         * varies depending on the proxy, use the catch-all {@link #exception} event instead.
         * This event will fire in addition to the {@link #exception} event.</p>
         * @param {misc} misc See {@link #exception}.
         * @deprecated
         */
        'loadexception',
        /**
         * @event beforewrite
         * <p>Fires before a request is generated for one of the actions Ext.data.Api.actions.create|update|destroy</p>
         * <p>In addition to being fired through the DataProxy instance that raised the event, this event is also fired
         * through the Ext.data.DataProxy <i>class</i> to allow for centralized processing of beforewrite events from <b>all</b>
         * DataProxies by attaching a listener to the Ext.data.DataProxy class itself.</p>
         * @param {DataProxy} this The proxy for the request
         * @param {String} action [Ext.data.Api.actions.create|update|destroy]
         * @param {Record/Record[]} rs The Record(s) to create|update|destroy.
         * @param {Object} params The request <code>params</code> object.  Edit <code>params</code> to add parameters to the request.
         */
        'beforewrite',
        /**
         * @event write
         * <p>Fires before the request-callback is called</p>
         * <p>In addition to being fired through the DataProxy instance that raised the event, this event is also fired
         * through the Ext.data.DataProxy <i>class</i> to allow for centralized processing of write events from <b>all</b>
         * DataProxies by attaching a listener to the Ext.data.DataProxy class itself.</p>
         * @param {DataProxy} this The proxy that sent the request
         * @param {String} action [Ext.data.Api.actions.create|upate|destroy]
         * @param {Object} data The data object extracted from the server-response
         * @param {Object} response The decoded response from server
         * @param {Record/Record[]} rs The Record(s) from Store
         * @param {Object} options The callback's <tt>options</tt> property as passed to the {@link #request} function
         */
        'write'
    );
    Ext.data.DataProxy.superclass.constructor.call(this);

    // Prepare the proxy api.  Ensures all API-actions are defined with the Object-form.
    try {
        Ext.data.Api.prepare(this);
    } catch (e) {
        if (e instanceof Ext.data.Api.Error) {
            e.toConsole();
        }
    }
    // relay each proxy's events onto Ext.data.DataProxy class for centralized Proxy-listening
    Ext.data.DataProxy.relayEvents(this, ['beforewrite', 'write', 'exception']);
};

Ext.extend(Ext.data.DataProxy, Ext.util.Observable, {
    /**
     * @cfg {Boolean} restful
     * <p>Defaults to <tt>false</tt>.  Set to <tt>true</tt> to operate in a RESTful manner.</p>
     * <br><p> Note: this parameter will automatically be set to <tt>true</tt> if the
     * {@link Ext.data.Store} it is plugged into is set to <code>restful: true</code>. If the
     * Store is RESTful, there is no need to set this option on the proxy.</p>
     * <br><p>RESTful implementations enable the serverside framework to automatically route
     * actions sent to one url based upon the HTTP method, for example:
     * <pre><code>
store: new Ext.data.Store({
    restful: true,
    proxy: new Ext.data.HttpProxy({url:'/users'}); // all requests sent to /users
    ...
)}
     * </code></pre>
     * If there is no <code>{@link #api}</code> specified in the configuration of the proxy,
     * all requests will be marshalled to a single RESTful url (/users) so the serverside
     * framework can inspect the HTTP Method and act accordingly:
     * <pre>
<u>Method</u>   <u>url</u>        <u>action</u>
POST     /users     create
GET      /users     read
PUT      /users/23  update
DESTROY  /users/23  delete
     * </pre></p>
     * <p>If set to <tt>true</tt>, a {@link Ext.data.Record#phantom non-phantom} record's
     * {@link Ext.data.Record#id id} will be appended to the url. Some MVC (e.g., Ruby on Rails,
     * Merb and Django) support segment based urls where the segments in the URL follow the
     * Model-View-Controller approach:<pre><code>
     * someSite.com/controller/action/id
     * </code></pre>
     * Where the segments in the url are typically:<div class="mdetail-params"><ul>
     * <li>The first segment : represents the controller class that should be invoked.</li>
     * <li>The second segment : represents the class function, or method, that should be called.</li>
     * <li>The third segment : represents the ID (a variable typically passed to the method).</li>
     * </ul></div></p>
     * <br><p>Refer to <code>{@link Ext.data.DataProxy#api}</code> for additional information.</p>
     */
    restful: false,

    /**
     * <p>Redefines the Proxy's API or a single action of an API. Can be called with two method signatures.</p>
     * <p>If called with an object as the only parameter, the object should redefine the <b>entire</b> API, e.g.:</p><pre><code>
proxy.setApi({
    read    : '/users/read',
    create  : '/users/create',
    update  : '/users/update',
    destroy : '/users/destroy'
});
</code></pre>
     * <p>If called with two parameters, the first parameter should be a string specifying the API action to
     * redefine and the second parameter should be the URL (or function if using DirectProxy) to call for that action, e.g.:</p><pre><code>
proxy.setApi(Ext.data.Api.actions.read, '/users/new_load_url');
</code></pre>
     * @param {String/Object} api An API specification object, or the name of an action.
     * @param {String/Function} url The URL (or function if using DirectProxy) to call for the action.
     */
    setApi : function() {
        if (arguments.length == 1) {
            var valid = Ext.data.Api.isValid(arguments[0]);
            if (valid === true) {
                this.api = arguments[0];
            }
            else {
                throw new Ext.data.Api.Error('invalid', valid);
            }
        }
        else if (arguments.length == 2) {
            if (!Ext.data.Api.isAction(arguments[0])) {
                throw new Ext.data.Api.Error('invalid', arguments[0]);
            }
            this.api[arguments[0]] = arguments[1];
        }
        Ext.data.Api.prepare(this);
    },

    /**
     * Returns true if the specified action is defined as a unique action in the api-config.
     * request.  If all API-actions are routed to unique urls, the xaction parameter is unecessary.  However, if no api is defined
     * and all Proxy actions are routed to DataProxy#url, the server-side will require the xaction parameter to perform a switch to
     * the corresponding code for CRUD action.
     * @param {String} action CREATE READ UPDATE or DESTROY
     * @return {Boolean}
     */
    isApiAction : function(action) {
        return (this.api[action]) ? true : false;
    },

    /**
     * All proxy actions are executed through this method.  Automatically fires the "before" + action event
     * @param {String} action Name of the action
     * @param {Ext.data.Record/Ext.data.Record[]/null} rs Will be null when action is 'load'
     * @param {Object} params
     * @param {Ext.data.DataReader} reader
     * @param {Function} callback
     * @param {Object} scope The scope (<code>this</code> reference) in which the callback function is executed. Defaults to the Proxy object.
     * @param {Object} options Any options specified for the action (e.g. see {@link Ext.data.Store#load}.
     */
    request : function(action, rs, params, reader, callback, scope, options) {
        if (!this.api[action] && !this.load) {
            throw new Ext.data.DataProxy.Error('action-undefined', action);
        }
        params = params || {};
        if ((action === Ext.data.Api.actions.read) ? this.fireEvent("beforeload", this, params) : this.fireEvent("beforewrite", this, action, rs, params) !== false) {
            this.doRequest.apply(this, arguments);
        }
        else {
            callback.call(scope || this, null, options, false);
        }
    },


    /**
     * <b>Deprecated</b> load method using old method signature. See {@doRequest} for preferred method.
     * @deprecated
     * @param {Object} params
     * @param {Object} reader
     * @param {Object} callback
     * @param {Object} scope
     * @param {Object} arg
     */
    load : null,

    /**
     * @cfg {Function} doRequest Abstract method that should be implemented in all subclasses.  <b>Note:</b> Should only be used by custom-proxy developers.
     * (e.g.: {@link Ext.data.HttpProxy#doRequest HttpProxy.doRequest},
     * {@link Ext.data.DirectProxy#doRequest DirectProxy.doRequest}).
     */
    doRequest : function(action, rs, params, reader, callback, scope, options) {
        // default implementation of doRequest for backwards compatibility with 2.0 proxies.
        // If we're executing here, the action is probably "load".
        // Call with the pre-3.0 method signature.
        this.load(params, reader, callback, scope, options);
    },

    /**
     * @cfg {Function} onRead Abstract method that should be implemented in all subclasses.  <b>Note:</b> Should only be used by custom-proxy developers.  Callback for read {@link Ext.data.Api#actions action}.
     * @param {String} action Action name as per {@link Ext.data.Api.actions#read}.
     * @param {Object} o The request transaction object
     * @param {Object} res The server response
     * @fires loadexception (deprecated)
     * @fires exception
     * @fires load
     * @protected
     */
    onRead : Ext.emptyFn,
    /**
     * @cfg {Function} onWrite Abstract method that should be implemented in all subclasses.  <b>Note:</b> Should only be used by custom-proxy developers.  Callback for <i>create, update and destroy</i> {@link Ext.data.Api#actions actions}.
     * @param {String} action [Ext.data.Api.actions.create|read|update|destroy]
     * @param {Object} trans The request transaction object
     * @param {Object} res The server response
     * @fires exception
     * @fires write
     * @protected
     */
    onWrite : Ext.emptyFn,
    /**
     * buildUrl
     * Sets the appropriate url based upon the action being executed.  If restful is true, and only a single record is being acted upon,
     * url will be built Rails-style, as in "/controller/action/32".  restful will aply iff the supplied record is an
     * instance of Ext.data.Record rather than an Array of them.
     * @param {String} action The api action being executed [read|create|update|destroy]
     * @param {Ext.data.Record/Ext.data.Record[]} record The record or Array of Records being acted upon.
     * @return {String} url
     * @private
     */
    buildUrl : function(action, record) {
        record = record || null;

        // conn.url gets nullified after each request.  If it's NOT null here, that means the user must have intervened with a call
        // to DataProxy#setUrl or DataProxy#setApi and changed it before the request was executed.  If that's the case, use conn.url,
        // otherwise, build the url from the api or this.url.
        var url = (this.conn && this.conn.url) ? this.conn.url : (this.api[action]) ? this.api[action].url : this.url;
        if (!url) {
            throw new Ext.data.Api.Error('invalid-url', action);
        }

        // look for urls having "provides" suffix used in some MVC frameworks like Rails/Merb and others.  The provides suffice informs
        // the server what data-format the client is dealing with and returns data in the same format (eg: application/json, application/xml, etc)
        // e.g.: /users.json, /users.xml, etc.
        // with restful routes, we need urls like:
        // PUT /users/1.json
        // DELETE /users/1.json
        var provides = null;
        var m = url.match(/(.*)(\.json|\.xml|\.html)$/);
        if (m) {
            provides = m[2];    // eg ".json"
            url      = m[1];    // eg: "/users"
        }
        // prettyUrls is deprectated in favor of restful-config
        if ((this.restful === true || this.prettyUrls === true) && record instanceof Ext.data.Record && !record.phantom) {
            url += '/' + record.id;
        }
        return (provides === null) ? url : url + provides;
    },

    /**
     * Destroys the proxy by purging any event listeners and cancelling any active requests.
     */
    destroy: function(){
        this.purgeListeners();
    }
});

// Apply the Observable prototype to the DataProxy class so that proxy instances can relay their
// events to the class.  Allows for centralized listening of all proxy instances upon the DataProxy class.
Ext.apply(Ext.data.DataProxy, Ext.util.Observable.prototype);
Ext.util.Observable.call(Ext.data.DataProxy);

/**
 * @class Ext.data.DataProxy.Error
 * @extends Ext.Error
 * DataProxy Error extension.
 * constructor
 * @param {String} message Message describing the error.
 * @param {Record/Record[]} arg
 */
Ext.data.DataProxy.Error = Ext.extend(Ext.Error, {
    constructor : function(message, arg) {
        this.arg = arg;
        Ext.Error.call(this, message);
    },
    name: 'Ext.data.DataProxy'
});
Ext.apply(Ext.data.DataProxy.Error.prototype, {
    lang: {
        'action-undefined': "DataProxy attempted to execute an API-action but found an undefined url / function.  Please review your Proxy url/api-configuration.",
        'api-invalid': 'Recieved an invalid API-configuration.  Please ensure your proxy API-configuration contains only the actions from Ext.data.Api.actions.'
    }
});


