function _read(op, blob) {
			var self = this;			

			this.trigger('loadstart');

			if (this.readyState === FileReader.LOADING) {
				this.trigger('error', new x.DOMException(x.DOMException.INVALID_STATE_ERR));
				this.trigger('loadend');
				return;
			}

			// if source is not o.Blob/o.File
			if (!(blob instanceof Blob)) {
				this.trigger('error', new x.DOMException(x.DOMException.NOT_FOUND_ERR));
				this.trigger('loadend');
				return;
			}

			this.result = null;
			this.readyState = FileReader.LOADING;
			
			if (blob.isDetached()) {
				var src = blob.getSource();
				switch (op) {
					case 'readAsText':
					case 'readAsBinaryString':
						this.result = src;
						break;
					case 'readAsDataURL':
						this.result = 'data:' + blob.type + ';base64,' + Encode.btoa(src);
						break;
				}
				this.readyState = FileReader.DONE;
				this.trigger('load');
				this.trigger('loadend');
			} else {
				this.connectRuntime(blob.ruid);
				this.exec('FileReader', 'read', op, blob);
			}
		}
Destroy component and release resources.

			@method destroy