/**
* Sencha GXT 3.1.0-beta - Sencha for GWT
* Copyright(c) 2007-2014, Sencha, Inc.
* licensing@sencha.com
*
* http://www.sencha.com/products/gxt/license/
*/
package com.sencha.gxt.data.client.loader;
import com.google.gwt.core.client.Callback;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.jsonp.client.JsonpRequestBuilder;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.sencha.gxt.data.shared.loader.DataProxy;
import com.sencha.gxt.data.shared.writer.DataWriter;
/**
* A {@link DataProxy} that reads a data from a URL which may be in a
* domain other than the originating domain of the running page.
*
* <p />
* Note that if you are retrieving data from a page that is in a domain that is
* NOT the same as the originating domain of the running page, you must use this
* class, rather than HttpProxy.
*
* <p />
* When using a load config object that implements <code>LoadConfig</code> or
* <code>ModelData</code>, all properties and property values will be sent as
* request parameters in the load request.
*
*
* @see HttpProxy
*/
public class ScriptTagProxy<C> implements DataProxy<C, JavaScriptObject> {
private String url;
private DataWriter<C, String> writer;
/**
* Creates a script tag proxy that reads data from a URL that may be in a
* domain other than the originating domain of the running page.
*
* @param url the URL representing the data to retrieve
*/
public ScriptTagProxy(String url) {
this.url = url;
}
/**
* Returns the data writer for this proxy. The data writer is responsible for
* encoding the load config.
*
* @return the data writer
*/
public DataWriter<C, String> getWriter() {
return writer;
}
public void load(C loadConfig, final Callback<JavaScriptObject, Throwable> callback) {
String prepend = url.indexOf("?") != -1 ? "&" : "?";
String u = url + prepend + generateUrl(loadConfig);
JsonpRequestBuilder b = new JsonpRequestBuilder();
b.requestObject(u, new AsyncCallback<JavaScriptObject>() {
@Override
public void onFailure(Throwable caught) {
callback.onFailure(caught);
}
@Override
public void onSuccess(JavaScriptObject result) {
callback.onSuccess(result);
}
});
}
/**
* Sets the proxy's url.
*
* @param url the url
*/
public void setUrl(String url) {
this.url = url;
}
/**
* Sets the data writer for this proxy. The data writer is responsible for
* encoding the load config.
*
* @param writer the data writer
*/
public void setWriter(DataWriter<C, String> writer) {
this.writer = writer;
}
/**
* Encodes the load config into a format that can be used for a GET query
* string or a POST url-encoded body. Use {@link #setWriter} to set the data
* writer responsible for encoding the load config. If it is not set the load
* config is assumed to require no further encoding and its value is retrieved
* using {@link Object#toString()}.
*
* @param loadConfig the load config to encode
* @return the encoded load config
*/
protected String generateUrl(C loadConfig) {
if (writer != null) {
return writer.write(loadConfig);
} else {
if (loadConfig == null) {
return "";
}
return loadConfig.toString();
}
}
}