/**
+ * @author Ed Spencer
+ * @class Ext.data.Operation
+ * @extends Object
+ *
+ * <p>Represents a single read or write operation performed by a {@link Ext.data.proxy.Proxy Proxy}.
+ * Operation objects are used to enable communication between Stores and Proxies. Application
+ * developers should rarely need to interact with Operation objects directly.</p>
+ *
+ * <p>Several Operations can be batched together in a {@link Ext.data.Batch batch}.</p>
+ *
+ * @constructor
+ * @param {Object} config Optional config object
+ */
+Ext.define('Ext.data.Operation', {
+ /**
+ * @cfg {Boolean} synchronous True if this Operation is to be executed synchronously (defaults to true). This
+ * property is inspected by a {@link Ext.data.Batch Batch} to see if a series of Operations can be executed in
+ * parallel or not.
+ */
+ synchronous: true,
+
+ /**
+ * @cfg {String} action The action being performed by this Operation. Should be one of 'create', 'read', 'update' or 'destroy'
+ */
+ action: undefined,
+
+ /**
+ * @cfg {Array} filters Optional array of filter objects. Only applies to 'read' actions.
+ */
+ filters: undefined,
+
+ /**
+ * @cfg {Array} sorters Optional array of sorter objects. Only applies to 'read' actions.
+ */
+ sorters: undefined,
+
+ /**
+ * @cfg {Object} group Optional grouping configuration. Only applies to 'read' actions where grouping is desired.
+ */
+ group: undefined,
+
+ /**
+ * @cfg {Number} start The start index (offset), used in paging when running a 'read' action.
+ */
+ start: undefined,
+
+ /**
+ * @cfg {Number} limit The number of records to load. Used on 'read' actions when paging is being used.
+ */
+ limit: undefined,
+
+ /**
+ * @cfg {Ext.data.Batch} batch The batch that this Operation is a part of (optional)
+ */
+ batch: undefined,
+
+ /**
+ * Read-only property tracking the start status of this Operation. Use {@link #isStarted}.
+ * @property started
+ * @type Boolean
+ * @private
+ */
+ started: false,
+
+ /**
+ * Read-only property tracking the run status of this Operation. Use {@link #isRunning}.
+ * @property running
+ * @type Boolean
+ * @private
+ */
+ running: false,
+
+ /**
+ * Read-only property tracking the completion status of this Operation. Use {@link #isComplete}.
+ * @property complete
+ * @type Boolean
+ * @private
+ */
+ complete: false,
+
+ /**
+ * Read-only property tracking whether the Operation was successful or not. This starts as undefined and is set to true
+ * or false by the Proxy that is executing the Operation. It is also set to false by {@link #setException}. Use
+ * {@link #wasSuccessful} to query success status.
+ * @property success
+ * @type Boolean
+ * @private
+ */
+ success: undefined,
+
+ /**
+ * Read-only property tracking the exception status of this Operation. Use {@link #hasException} and see {@link #getError}.
+ * @property exception
+ * @type Boolean
+ * @private
+ */
+ exception: false,
+
+ /**
+ * The error object passed when {@link #setException} was called. This could be any object or primitive.
+ * @property error
+ * @type Mixed
+ * @private
+ */
+ error: undefined,
+
+ constructor: function(config) {
+ Ext.apply(this, config || {});
+ },
+
+ /**
+ * Marks the Operation as started
+ */
+ setStarted: function() {
+ this.started = true;
+ this.running = true;
+ },
+
+ /**
+ * Marks the Operation as completed
+ */
+ setCompleted: function() {
+ this.complete = true;
+ this.running = false;
+ },
+
+ /**
+ * Marks the Operation as successful
+ */
+ setSuccessful: function() {
+ this.success = true;
+ },
+
+ /**
+ * Marks the Operation as having experienced an exception. Can be supplied with an option error message/object.
+ * @param {Mixed} error Optional error string/object
+ */
+ setException: function(error) {
+ this.exception = true;
+ this.success = false;
+ this.running = false;
+ this.error = error;
+ },
+
+ /**
+ * Returns true if this Operation encountered an exception (see also {@link #getError})
+ * @return {Boolean} True if there was an exception
+ */
+ hasException: function() {
+ return this.exception === true;
+ },
+
+ /**
+ * Returns the error string or object that was set using {@link #setException}
+ * @return {Mixed} The error object
+ */
+ getError: function() {
+ return this.error;
+ },
+
+ /**
+ * Returns an array of Ext.data.Model instances as set by the Proxy.
+ * @return {Array} Any loaded Records
+ */
+ getRecords: function() {
+ var resultSet = this.getResultSet();
+
+ return (resultSet === undefined ? this.records : resultSet.records);
+ },
+
+ /**
+ * Returns the ResultSet object (if set by the Proxy). This object will contain the {@link Ext.data.Model model} instances
+ * as well as meta data such as number of instances fetched, number available etc
+ * @return {Ext.data.ResultSet} The ResultSet object
+ */
+ getResultSet: function() {
+ return this.resultSet;
+ },
+
+ /**
+ * Returns true if the Operation has been started. Note that the Operation may have started AND completed,
+ * see {@link #isRunning} to test if the Operation is currently running.
+ * @return {Boolean} True if the Operation has started
+ */
+ isStarted: function() {
+ return this.started === true;
+ },
+
+ /**
+ * Returns true if the Operation has been started but has not yet completed.
+ * @return {Boolean} True if the Operation is currently running
+ */
+ isRunning: function() {
+ return this.running === true;
+ },
+
+ /**
+ * Returns true if the Operation has been completed
+ * @return {Boolean} True if the Operation is complete
+ */
+ isComplete: function() {
+ return this.complete === true;
+ },
+
+ /**
+ * Returns true if the Operation has completed and was successful
+ * @return {Boolean} True if successful
+ */
+ wasSuccessful: function() {
+ return this.isComplete() && this.success === true;
+ },
+
+ /**
+ * @private
+ * Associates this Operation with a Batch
+ * @param {Ext.data.Batch} batch The batch
+ */
+ setBatch: function(batch) {
+ this.batch = batch;
+ },
+
+ /**
+ * Checks whether this operation should cause writing to occur.
+ * @return {Boolean} Whether the operation should cause a write to occur.
+ */
+ allowWrite: function() {
+ return this.action != 'read';
+ }
+});