Synnefo » Pithos

/*

 * Copyright (c) 2011 Greek Research and Technology Network

 */

package gr.grnet.pithos.web.client.rest;

import com.google.gwt.core.client.GWT;

import com.google.gwt.core.client.Scheduler.ScheduledCommand;

import com.google.gwt.http.client.Request;

import com.google.gwt.http.client.RequestBuilder;

import com.google.gwt.http.client.RequestException;

import com.google.gwt.http.client.Response;

import gr.grnet.pithos.web.client.foldertree.Resource;

import java.util.HashMap;

import java.util.Map;

public abstract class GetRequest<T extends Resource> implements ScheduledCommand {

    private Class<T> aClass;

    private String path;

    private int okCode;

    private String username;

    private T cached;

    private Map<String, String> headers = new HashMap<String, String>();

    public abstract void onSuccess(T result);

    public abstract void onError(Throwable t);

    public GetRequest(Class<T> aClass, String path, int okCode) {

        this.aClass = aClass;

        this.path = path;

        this.okCode = okCode;

    }

    public GetRequest(Class<T> aClass, String path) {

        this(aClass, path, -1);

    }

    @Override

    public void execute() {

        RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, path);

        for (String header : headers.keySet())

            builder.setHeader(header, headers.get(header));

        try {

            builder.sendRequest("", new RestRequestCallback<T>(path, okCode) {

                @Override

                public void onSuccess(T object) {

                    GetRequest.this.onSuccess(object);

                }

                @Override

                public T deserialize(Response response) {

                    return Resource.createFromResponse(aClass, response);

                }

                @Override

                public void onError(Request request, Throwable throwable) {

                    if (throwable instanceof RestException) {

                        if (((RestException) throwable).getHttpStatusCode() == 304 && cached != null){

                            GWT.log("Using cache: " + cached.getUri(), null);

                            onSuccess(cached);

                            return;

                        }

                    }

                    GetRequest.this.onError(throwable);

                }

            });

        }

        catch (RequestException e) {

        }

    }

    public void setHeader(String header, String value) {

        headers.put(header, value);

    }

}