com.extjs.gxt.ui.client.data.HttpProxy.java Source code

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Here is the source code for com.extjs.gxt.ui.client.data.HttpProxy.java

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/*
 * Sencha GXT 2.3.1 - Sencha for GWT
 * Copyright(c) 2007-2013, Sencha, Inc.
 * licensing@sencha.com
 * 
 * http://www.sencha.com/products/gxt/license/
 */
package com.extjs.gxt.ui.client.data;

import java.util.Map;

import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.Response;
import com.google.gwt.user.client.rpc.AsyncCallback;

/**
 * A concrete <code>DataProxy</code> that retrieves data using a
 * <code>RequestBulder</code> instances.
 * 
 * <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.
 * 
 * @param <D> the data type being returned by the proxy
 * 
 * @see RequestBuilder
 * @see ScriptTagProxy
 */
public class HttpProxy<D> implements DataProxy<D> {

    protected RequestBuilder builder;
    protected String initUrl;

    /**
     * Creates a new HttpProxy.
     * 
     * @param builder the request builder
     */
    public HttpProxy(RequestBuilder builder) {
        this.builder = builder;
        this.initUrl = builder.getUrl();
    }

    public void load(final DataReader<D> reader, final Object loadConfig, final AsyncCallback<D> callback) {
        try {
            String data = null;
            if (builder.getHTTPMethod().equals("POST")) {
                data = generateUrl(loadConfig);
            } else {
                String url = initUrl;
                url = url + (url.indexOf("?") == -1 ? "?" : "&");
                String params = generateUrl(loadConfig);
                url += params;
                setUrl(builder, url);
            }

            builder.sendRequest(data, new RequestCallback() {
                public void onError(Request request, Throwable exception) {
                    callback.onFailure(exception);
                }

                @SuppressWarnings("unchecked")
                public void onResponseReceived(Request request, Response response) {
                    if (response.getStatusCode() != Response.SC_OK) {
                        callback.onFailure(
                                new RuntimeException("HttpProxy: Invalid status code " + response.getStatusCode()));
                        return;
                    }
                    String text = response.getText();
                    try {
                        D data = null;
                        if (reader != null) {
                            data = reader.read(loadConfig, text);
                        } else {
                            data = (D) text;
                        }
                        callback.onSuccess(data);
                    } catch (Exception e) {
                        e.printStackTrace();
                        callback.onFailure(e);
                    }
                }
            });
        } catch (Exception e) {
            callback.onFailure(e);
        }
    }

    protected String generateUrl(Object loadConfig) {
        StringBuffer sb = new StringBuffer();
        if (loadConfig instanceof ModelData) {
            Map<String, Object> map = ((ModelData) loadConfig).getProperties();
            for (String key : map.keySet()) {
                sb.append("&" + key + "=" + map.get(key));
            }
        }
        if (sb.length() > 0) {
            return sb.substring(1, sb.length());
        }
        return sb.toString();
    }

    private native void setUrl(RequestBuilder rb, String url) /*-{
                                                              rb.@com.google.gwt.http.client.RequestBuilder::url = url;
                                                              }-*/;
}