com.epam.feel.client.ui.util.gwtupload.FixedUploader.java Source code

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/*
 * Copyright 2010 Manuel Carrasco Moino. (manolo at apache/org) 
 * http://code.google.com/p/gwtupload
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.epam.feel.client.ui.util.gwtupload;

import static gwtupload.shared.UConsts.LEGACY_TAG_MSG_START;
import static gwtupload.shared.UConsts.TAG_BLOBSTORE_PATH;
import static gwtupload.shared.UConsts.TAG_CANCELED;
import static gwtupload.shared.UConsts.TAG_CTYPE;
import static gwtupload.shared.UConsts.TAG_CURRENT_BYTES;
import static gwtupload.shared.UConsts.TAG_FIELD;
import static gwtupload.shared.UConsts.TAG_FINISHED;
import static gwtupload.shared.UConsts.TAG_MESSAGE;
import static gwtupload.shared.UConsts.TAG_MSG_END;
import static gwtupload.shared.UConsts.TAG_MSG_GT;
import static gwtupload.shared.UConsts.TAG_MSG_LT;
import static gwtupload.shared.UConsts.TAG_MSG_START;
import static gwtupload.shared.UConsts.TAG_NAME;
import static gwtupload.shared.UConsts.TAG_PERCENT;
import static gwtupload.shared.UConsts.TAG_SIZE;
import static gwtupload.shared.UConsts.TAG_TOTAL_BYTES;
import static gwtupload.shared.UConsts.TAG_WAIT;
import gwtupload.client.BaseUploadStatus;
import gwtupload.client.HasJsData;
import gwtupload.client.IFileInput;
import gwtupload.client.IFileInput.FileInputType;
import gwtupload.client.IUploadStatus;
import gwtupload.client.IUploadStatus.Status;
import gwtupload.client.IUploader;
import gwtupload.client.IsUpdateable;
import gwtupload.client.UpdateTimer;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.Vector;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.event.dom.client.ChangeEvent;
import com.google.gwt.event.dom.client.ChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
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.RequestException;
import com.google.gwt.http.client.RequestTimeoutException;
import com.google.gwt.http.client.Response;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.FormPanel;
import com.google.gwt.user.client.ui.FormPanel.SubmitCompleteEvent;
import com.google.gwt.user.client.ui.FormPanel.SubmitCompleteHandler;
import com.google.gwt.user.client.ui.FormPanel.SubmitEvent;
import com.google.gwt.user.client.ui.FormPanel.SubmitHandler;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Hidden;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Panel;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.xml.client.Document;
import com.google.gwt.xml.client.XMLParser;
import com.google.gwt.xml.client.impl.DOMParseException;

/**
 * <p>
 * Uploader panel.
 * </p>
 * 
 * @author Manolo Carrasco Moino <h3>Features</h3>
 *         <ul>
 *         <li>Renders a form with an input file for sending the file, and a hidden iframe where is received the server
 *         response</li>
 *         <li>The user can add more elements to the form</li>
 *         <li>It asks the server for the upload progress continuously until the submit process has finished.</li>
 *         <li>It expects xml responses instead of gwt-rpc, so the server part can be implemented in any language</li>
 *         <li>It uses a progress interface so it is easy to use customized progress bars</li>
 *         <li>By default it renders a basic progress bar</li>
 *         <li>It can be configured to automatic submit after the user has selected the file</li>
 *         <li>It uses a queue that avoid submit more than a file at the same time</li>
 *         </ul>
 *         <h3>CSS Style Rules</h3>
 *         <ul>
 *         <li>.GWTUpld { Uploader container }</li>
 *         <li>.GWTUpld .upld-input { style for the FileInput element }</li>
 *         <li>.GWTUpld .upld-status { style for the IUploadStatus element }</li>
 *         <li>.GWTUpld .upld-button { style for submit button if present }</li>
 *         </ul>
 */
public class FixedUploader extends Composite implements IsUpdateable, IUploader, HasJsData {

    public Widget getWidget() {
        return this;
    }

    /**
     * FormPanel add method only can be called once. This class override the add method to allow multiple additions to a
     * flowPanel.
     */
    public class FormFlowPanel extends FormPanel {
        FlowPanel formElements = new FlowPanel();

        public FormFlowPanel() {
            super.add(formElements);
            formElements.setStyleName("upld-form-elements");
        }

        public void add(Widget w) {
            if (w instanceof Hidden) {
                formElements.insert(w, 0);
            } else {
                formElements.add(w);
            }
        }

        public void add(Widget w, int index) {
            formElements.insert(w, Math.max(0, Math.min(index, formElements.getWidgetCount())));
        }

        public void clear() {
            formElements.clear();
            add(fileInput.getWidget());
        }
    }

    public static final int DEFAULT_FILEINPUT_SIZE = 40;

    public static final UploaderConstants I18N_CONSTANTS = GWT.create(UploaderConstants.class);
    public static final String PARAMETER_FILENAME = "filename";
    public static final String PARAMETER_SHOW = "show";
    protected static final String STYLE_BUTTON = "upld-button";

    protected static final String STYLE_INPUT = "upld-input";
    protected static final String STYLE_MAIN = "GWTUpld";
    protected static final String STYLE_STATUS = "upld-status";
    static HTML mlog;
    private static final int DEFAULT_AJAX_TIMEOUT = 10000;
    private static final int DEFAULT_AUTOUPLOAD_DELAY = 600;

    private static final int DEFAULT_TIME_MAX_WITHOUT_RESPONSE = 60000;
    private static final int DEFAULT_UPDATE_INTERVAL = 500;

    private static HashSet<String> fileDone = new HashSet<String>();
    private static Vector<String> fileQueue = new Vector<String>();
    private static int statusInterval = DEFAULT_UPDATE_INTERVAL;

    private static int uploadTimeout = DEFAULT_TIME_MAX_WITHOUT_RESPONSE;

    public static void log(String msg, Throwable e) {
        GWT.log(msg, e);
    }

    /**
     * Configure the frequency to send status requests to the server.
     */
    public static void setStatusInterval(int statusInterval) {
        FixedUploader.statusInterval = statusInterval;
    }

    /**
     * Configure the maximal time without a valid response from the server. When this period is reached, the upload
     * process is canceled.
     */
    public static void setUploadTimeout(int uploadTimeout) {
        FixedUploader.uploadTimeout = uploadTimeout;
    }

    private static long now() {
        return (new Date()).getTime();
    }

    protected Panel uploaderPanel;
    private final Timer automaticUploadTimer = new Timer() {
        private boolean firstTime = true;

        public void run() {
            if (isTheFirstInQueue()) {
                this.cancel();
                firstTime = true;
                statusWidget.setStatus(IUploadStatus.Status.SUBMITING);
                statusWidget.setVisible(true);
                uploadForm.submit();
            } else if (firstTime) {
                addToQueue();
                firstTime = false;
            }
        }

        public void cancel() {
            super.cancel();
            firstTime = true;
        };
    };

    protected boolean autoSubmit = false;
    private boolean avoidRepeatedFiles = false;
    private boolean avoidEmptyFile = true;
    private String basename = "";
    private boolean blobstore = false;
    private IUploadStatus.UploadCancelHandler cancelHandler = new IUploadStatus.UploadCancelHandler() {
        public void onCancel() {
            cancel();
        }
    };
    private boolean canceled = false;
    private boolean enabled = true;
    private IFileInput fileInput;
    protected String fileInputPrefix = "GWTU";
    private FileInputType fileInputType;
    private boolean finished = false;
    private boolean hasSession = false;
    private long lastData = now();
    private final RequestCallback onBlobstoreReceivedCallback = new RequestCallback() {
        public void onError(Request request, Throwable exception) {
            String message = removeHtmlTags(exception.getMessage());
            cancelUpload(i18nStrs.uploaderServerUnavailable() + " (1) " + getServletPath() + "\n\n" + message);
        }

        public void onResponseReceived(Request request, Response response) {
            String text = response.getText();
            String url = null;
            try {
                url = Utils.getXmlNodeValue(XMLParser.parse(text), TAG_BLOBSTORE_PATH);
            } catch (DOMParseException e) {
                String bpath = "<" + TAG_BLOBSTORE_PATH + ">";
                String sbpath = "</" + TAG_BLOBSTORE_PATH + ">";
                if (text.contains(bpath)) {
                    url = text.replaceAll("[\r\n]+", "").replaceAll("^.*" + bpath + "\\s*", "")
                            .replaceAll("\\s*" + sbpath + ".*$", "");
                }
            } catch (Exception e) {
                cancelUpload(i18nStrs.uploaderBlobstoreError() + "\n>>>\n" + e.getMessage() + "\n>>>>\n" + e);
                return;
            }
            if (url != null && url.length() > 0 && !"null".equalsIgnoreCase(url)) {
                uploadForm.setAction(url);
            }
            receivedBlobPath = true;
            uploadForm.submit();
        }
    };

    private final RequestCallback onCancelReceivedCallback = new RequestCallback() {
        public void onError(Request request, Throwable exception) {
            log("onCancelReceivedCallback onError: ", exception);
            statusWidget.setStatus(IUploadStatus.Status.CANCELED);
        }

        public void onResponseReceived(Request request, Response response) {
            if (getStatus() == Status.CANCELING) {
                updateStatusTimer.scheduleRepeating(3000);
            }
        }
    };

    private Vector<IUploader.OnChangeUploaderHandler> onChangeHandlers = new Vector<IUploader.OnChangeUploaderHandler>();
    private final RequestCallback onDeleteFileCallback = new RequestCallback() {
        public void onError(Request request, Throwable exception) {
            statusWidget.setStatus(Status.DELETED);
            log("onCancelReceivedCallback onError: ", exception);
        }

        public void onResponseReceived(Request request, Response response) {
            statusWidget.setStatus(Status.DELETED);
            fileDone.remove(getFileName());
        }
    };
    private final ChangeHandler onFileInputChanged = new ChangeHandler() {
        public void onChange(ChangeEvent event) {
            basename = Utils.basename(getFileName());
            statusWidget.setFileName(basename);
            if (avoidRepeatedFiles && fileDone.contains(getFileName())) {
                statusWidget.setStatus(Status.REPEATED);
                return;
            }
            if (autoSubmit && !validateExtension(basename)) {
                return;
            }
            if (autoSubmit && basename.length() > 0) {
                automaticUploadTimer.scheduleRepeating(DEFAULT_AUTOUPLOAD_DELAY);
            }
            onChangeInput();
        }
    };

    private Vector<IUploader.OnFinishUploaderHandler> onFinishHandlers = new Vector<IUploader.OnFinishUploaderHandler>();

    private final RequestCallback onSessionReceivedCallback = new RequestCallback() {
        public void onError(Request request, Throwable exception) {
            String message = removeHtmlTags(exception.getMessage());
            cancelUpload(i18nStrs.uploaderServerUnavailable() + " (2) " + getServletPath() + "\n\n" + message);
        }

        public void onResponseReceived(Request request, Response response) {
            hasSession = true;
            try {
                String s = Utils.getXmlNodeValue(XMLParser.parse(response.getText()), "blobstore");
                blobstore = "true".equalsIgnoreCase(s);
                // with blobstore status does not make sense
                if (blobstore) {
                    updateStatusTimer.setInterval(5000);
                }
                uploadForm.submit();
            } catch (Exception e) {
                String message = e.getMessage().contains("error:")
                        ? i18nStrs.uploaderServerUnavailable() + " (3) " + getServletPath() + "\n\n"
                                + i18nStrs.uploaderServerError() + "\nAction: " + getServletPath() + "\nException: "
                                + e.getMessage() + response.getText()
                        : i18nStrs.submitError();
                cancelUpload(message);
            }
        }
    };

    private Vector<IUploader.OnStartUploaderHandler> onStartHandlers = new Vector<IUploader.OnStartUploaderHandler>();

    private Vector<IUploader.OnStatusChangedHandler> onStatusChangeHandlers = new Vector<IUploader.OnStatusChangedHandler>();

    /**
     * Handler called when the status request response comes back. In case of success it parses the xml document
     * received and updates the progress widget In case of a non timeout error, it stops the status repeater and
     * notifies the user with the exception.
     */
    private final RequestCallback onStatusReceivedCallback = new RequestCallback() {
        public void onError(Request request, Throwable exception) {
            waitingForResponse = false;
            if (exception instanceof RequestTimeoutException) {
                log("GWTUpload: onStatusReceivedCallback timeout error, asking the server again.", null);
            } else {
                log("GWTUpload: onStatusReceivedCallback error: " + exception.getMessage(), exception);
                updateStatusTimer.cancel();
                String message = removeHtmlTags(exception.getMessage());
                message += "\n" + exception.getClass().getName();
                message += "\n" + exception.toString();
                statusWidget.setError(
                        i18nStrs.uploaderServerUnavailable() + " (4) " + getServletPath() + "\n\n" + message);
            }
        }

        public void onResponseReceived(Request request, Response response) {
            waitingForResponse = false;
            if (finished == true && !uploading) {
                updateStatusTimer.cancel();
                return;
            }
            parseAjaxResponse(response.getText());
        }

    };

    private boolean onSubmitComplete;

    private SubmitCompleteHandler onSubmitCompleteHandler = new SubmitCompleteHandler() {
        @SuppressWarnings("deprecation")
        public void onSubmitComplete(SubmitCompleteEvent event) {
            updateStatusTimer.cancel();
            onSubmitComplete = true;
            serverResponse = event.getResults();
            if (serverResponse != null) {
                serverResponse = serverResponse.replaceFirst(
                        ".*(" + TAG_MSG_START + "|" + LEGACY_TAG_MSG_START + ")([\\s\\S]*?)" + TAG_MSG_END + ".*",
                        "$2");
                serverResponse = serverResponse.replace(TAG_MSG_LT, "<").replace(TAG_MSG_GT, ">")
                        .replace("&lt;", "<").replaceAll("&gt;", ">");
            }
            log("onSubmitComplete: " + serverResponse, null);
            try {
                // Parse the xml and extract serverInfo
                Document doc = XMLParser.parse(serverResponse);
                serverInfo.name = Utils.getXmlNodeValue(doc, TAG_NAME);
                serverInfo.ctype = Utils.getXmlNodeValue(doc, TAG_CTYPE);
                String size = Utils.getXmlNodeValue(doc, TAG_SIZE);
                if (size != null) {
                    serverInfo.size = Integer.parseInt(size);
                }
                serverInfo.field = Utils.getXmlNodeValue(doc, TAG_FIELD);
                serverInfo.message = Utils.getXmlNodeValue(doc, TAG_MESSAGE);

                // If the server response is a valid xml
                parseAjaxResponse(serverResponse);
            } catch (Exception e) {
                // Otherwise force an ajax request so as we have not to wait to the timer schedule
                updateStatusTimer.run();
            }
        }
    };

    /**
     * Handler called when the file form is submitted If any validation fails, the upload process is canceled. If the
     * client hasn't got the session, it asks for a new one and the submit process is delayed until the client has got
     * it
     */
    private SubmitHandler onSubmitFormHandler = new SubmitHandler() {
        public void onSubmit(SubmitEvent event) {
            if (!finished && uploading) {
                uploading = false;
                statusWidget.setStatus(IUploadStatus.Status.CANCELED);
                return;
            }

            if (!autoSubmit && fileQueue.size() > 0) {
                statusWidget.setError(i18nStrs.uploaderActiveUpload());
                event.cancel();
                return;
            }

            if (avoidRepeatedFiles && fileDone.contains(getFileName())) {
                statusWidget.setStatus(IUploadStatus.Status.REPEATED);
                successful = true;
                event.cancel();
                uploadFinished();
                return;
            }

            if (!validateExtension(basename)) {
                event.cancel();
                return;
            }

            if (!hasSession) {
                event.cancel();
                try {
                    sendAjaxRequestToValidateSession();
                } catch (Exception e) {
                    log("Exception in validateSession", null);
                }
                return;
            }

            if (blobstore && !receivedBlobPath) {
                event.cancel();
                try {
                    sendAjaxRequestToGetBlobstorePath();
                } catch (Exception e) {
                    log("Exception in getblobstorePath", null);
                }
                return;
            }
            receivedBlobPath = false;

            addToQueue();
            uploading = true;
            finished = false;
            serverResponse = null;
            serverInfo = new UploadedInfo();

            statusWidget.setVisible(true);
            updateStatusTimer.squeduleStart();
            statusWidget.setStatus(IUploadStatus.Status.INPROGRESS);
            lastData = now();
        }
    };

    private boolean receivedBlobPath = false;

    private int requestsCounter = 0;

    private String serverResponse = null;
    protected UploadedInfo serverInfo = new UploadedInfo();

    private String servletPath = "servlet.gupld";

    private IUploadStatus.UploadStatusChangedHandler statusChangedHandler = new IUploadStatus.UploadStatusChangedHandler() {
        public void onStatusChanged(IUploadStatus statusWiget) {
            for (IUploader.OnStatusChangedHandler handler : onStatusChangeHandlers) {
                handler.onStatusChanged(thisInstance);
            }
        }
    };

    private IUploadStatus statusWidget = new BaseUploadStatus();

    protected UploaderConstants i18nStrs = I18N_CONSTANTS;

    private boolean successful = false;

    private FixedUploader thisInstance;

    private final UpdateTimer updateStatusTimer = new UpdateTimer(this, statusInterval);

    private FormPanel uploadForm;

    private boolean uploading = false;

    private String[] validExtensions = null;

    private String validExtensionsMsg = "";

    private boolean waitingForResponse = false;

    /**
     * Default constructor. Initialize widget components and layout elements using the standard file input.
     */
    public FixedUploader() {
        this(FileInputType.BROWSER_INPUT);
    }

    /**
     * Initialize widget components and layout elements using the standard file input.
     * 
     * @param automaticUpload
     *            when true the upload starts as soon as the user selects a file
     */
    public FixedUploader(boolean automaticUpload) {
        this(FileInputType.BROWSER_INPUT, automaticUpload);
    }

    /**
     * Initialize widget components and layout elements.
     * 
     * @param type
     *            file input to use
     */
    public FixedUploader(FileInputType type) {
        this(type, null);
    }

    /**
     * Initialize widget components and layout elements.
     * 
     * @param type
     *            file input to use
     * @param automaticUpload
     *            when true the upload starts as soon as the user selects a file
     */
    public FixedUploader(FileInputType type, boolean automaticUpload) {
        this(type);
        setAutoSubmit(automaticUpload);
    }

    /**
     * Initialize widget components and layout elements.
     * 
     * @param type
     *            file input to use
     * @param form
     *            An existing form panel to use
     */
    public FixedUploader(FileInputType type, FormPanel form) {
        thisInstance = this;
        this.fileInputType = type;

        if (form == null) {
            form = new FormFlowPanel();
        }
        uploadForm = form;
        uploadForm.setEncoding(FormPanel.ENCODING_MULTIPART);
        uploadForm.setMethod(FormPanel.METHOD_POST);
        uploadForm.setAction(servletPath);
        uploadForm.addSubmitHandler(onSubmitFormHandler);
        uploadForm.addSubmitCompleteHandler(onSubmitCompleteHandler);

        uploaderPanel = getUploaderPanel();
        uploaderPanel.add(uploadForm);
        uploaderPanel.setStyleName(STYLE_MAIN);

        setFileInput(fileInputType.getInstance());

        setStatusWidget(statusWidget);

        super.initWidget(uploaderPanel);
    }

    protected Panel getUploaderPanel() {
        return new HorizontalPanel();
    }

    /**
     * Adds a widget to formPanel.
     */
    public void add(Widget w) {
        uploadForm.add(w);
    }

    /**
     * Adds a widget to formPanel in a specified position.
     */
    public void add(Widget w, int index) {
        if (uploadForm instanceof FormFlowPanel) {
            ((FormFlowPanel) uploadForm).add(w, index);
        } else {
            add(w);
        }
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#addOnCancelUploadHandler(gwtupload.client.IUploader.OnCancelUploaderHandler)
     */
    public HandlerRegistration addOnCancelUploadHandler(final OnCancelUploaderHandler handler) {
        assert handler != null;
        return statusWidget.addCancelHandler(new IUploadStatus.UploadCancelHandler() {
            public void onCancel() {
                handler.onCancel(thisInstance);
            }
        });
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#addOnChangeUploadHandler(gwtupload.client.IUploader.OnChangeUploaderHandler)
     */
    public HandlerRegistration addOnChangeUploadHandler(final IUploader.OnChangeUploaderHandler handler) {
        assert handler != null;
        onChangeHandlers.add(handler);
        return new HandlerRegistration() {
            public void removeHandler() {
                onChangeHandlers.remove(handler);
            }
        };
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#addOnFinishUploadHandler(gwtupload.client.IUploader.OnFinishUploaderHandler)
     */
    public HandlerRegistration addOnFinishUploadHandler(final IUploader.OnFinishUploaderHandler handler) {
        assert handler != null;
        onFinishHandlers.add(handler);
        return new HandlerRegistration() {
            public void removeHandler() {
                onFinishHandlers.remove(handler);
            }
        };
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#addOnStartUploadHandler(gwtupload.client.IUploader.OnStartUploaderHandler)
     */
    public HandlerRegistration addOnStartUploadHandler(final IUploader.OnStartUploaderHandler handler) {
        assert handler != null;
        onStartHandlers.add(handler);
        return new HandlerRegistration() {
            public void removeHandler() {
                onStartHandlers.remove(handler);
            }
        };
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#addOnStatusChangedHandler(gwtupload.client.IUploader.OnStatusChangedHandler)
     */
    public HandlerRegistration addOnStatusChangedHandler(final OnStatusChangedHandler handler) {
        assert handler != null;
        onStatusChangeHandlers.add(handler);
        return new HandlerRegistration() {
            public void removeHandler() {
                onStatusChangeHandlers.remove(handler);
            }
        };
    }

    /**
     * Don't send files that have already been uploaded.
     */
    public void avoidRepeatFiles(boolean avoidRepeat) {
        this.avoidRepeatedFiles = avoidRepeat;
    }

    /**
     * Don't submit the form if the user has not selected any file. It is useful in forms where the developer whats the
     * user to submit information but the attachment is optional. By default avoidEmptyFile is true.
     */
    public void avoidEmptyFiles(boolean b) {
        this.avoidEmptyFile = b;
    }

    /**
     * Cancel the current upload process.
     */
    public void cancel() {
        if (finished && !uploading) {
            if (successful) {
                try {
                    sendAjaxRequestToDeleteUploadedFile();
                } catch (Exception e) {
                }
            } else {
                statusWidget.setStatus(Status.DELETED);
            }
            return;
        }

        if (getStatus() == Status.CANCELED) {
            return;
        }

        canceled = true;
        automaticUploadTimer.cancel();
        log("cancelling " + uploading, null);
        if (uploading) {
            updateStatusTimer.cancel();
            try {
                sendAjaxRequestToCancelCurrentUpload();
            } catch (Exception e) {
                log("Exception cancelling request " + e.getMessage(), e);
            }
            statusWidget.setStatus(IUploadStatus.Status.CANCELING);
        } else {
            uploadFinished();
        }
    }

    /**
     * Remove all widget from the form.
     */
    public void clear() {
        uploadForm.clear();
    }

    /**
     * Returns the link for getting the uploaded file from the server It's useful to display uploaded images or generate
     * links to uploaded files.
     */
    public String fileUrl() {
        return composeURL(PARAMETER_SHOW + "=" + getInputName());
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#getBasename()
     */
    public String getBasename() {
        return Utils.basename(getFileName());
    }

    /**
     * Returns a JavaScriptObject properties with the url of the uploaded file. It's useful in the exported version of
     * the library. Because native javascript needs it
     */
    public JavaScriptObject getData() {
        return getDataImpl(fileUrl(), getInputName(), getFileName(), getBasename(), getServerResponse(),
                getServerInfo().message, getStatus().toString(), getServerInfo().size);
    }

    public IFileInput getFileInput() {
        return fileInput;
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#getFileName()
     */
    public String getFileName() {
        return fileInput.getFilename();
    }

    public FormPanel getForm() {
        return uploadForm;
    }

    public UploaderConstants getI18NConstants() {
        return i18nStrs;
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#getInputName()
     */
    public String getInputName() {
        return fileInput.getName();
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#getServerResponse()
     */
    public String getServerResponse() {
        return serverResponse;
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#getServerInfo()
     */
    public UploadedInfo getServerInfo() {
        return serverInfo;
    }

    /**
     * return the configured server service in the form-panel.
     */
    public String getServletPath() {
        return servletPath;
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#getStatus()
     */
    public Status getStatus() {
        return statusWidget.getStatus();
    }

    /**
     * Get the status progress used.
     */
    public IUploadStatus getStatusWidget() {
        return statusWidget;
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#isEnabled()
     */
    public boolean isEnabled() {
        return enabled;
    }

    public boolean isFinished() {
        return finished;
    }

    /**
     * Returns a iterator of the widgets contained in the form panel.
     */
    public Iterator<Widget> iterator() {
        return uploadForm.iterator();
    }

    /**
     * remove a widget from the form panel.
     */
    public boolean remove(Widget w) {
        return uploadForm.remove(w);
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#reset()
     */
    public void reset() {
        reuse();
        fileDone.clear();
    }

    /**
     * Prepare the uploader for a new upload.
     */
    public void reuse() {
        this.uploadForm.reset();
        updateStatusTimer.cancel();
        onSubmitComplete = uploading = canceled = finished = successful = false;
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#setAutoSubmit(boolean)
     */
    public void setAutoSubmit(boolean b) {
        autoSubmit = b;
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#setEnabled(boolean)
     */
    public void setEnabled(boolean b) {
        enabled = b;
        if (fileInput != null) {
            fileInput.setEnabled(b);
        }
    }

    public void setFileInput(IFileInput input) {
        if (fileInput != null) {
            fileInput.getWidget().removeFromParent();
        }
        fileInput = input;
        fileInput.addChangeHandler(onFileInputChanged);
        fileInput.setText(i18nStrs.uploaderBrowse());
        fileInput.setEnabled(enabled);
        setFileInputSize(DEFAULT_FILEINPUT_SIZE);
        assignNewNameToFileInput();
        uploadForm.add(fileInput.getWidget());
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#setFileInputPrefix(java.lang.String)
     */
    public void setFileInputPrefix(String prefix) {
        fileInputPrefix = prefix;
        assignNewNameToFileInput();
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#setFileInputSize(int)
     */
    public void setFileInputSize(int length) {
        fileInput.setLength(length);
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#setI18Constants(gwtupload.client.I18nUploadConstants)
     */
    public void setI18Constants(UploaderConstants strs) {
        this.i18nStrs = strs;
        fileInput.setText(strs.uploaderBrowse());
        statusWidget.setI18Constants(strs);
    }

    /**
     * set the url of the server service that receives the files and informs about the progress.
     */
    public void setServletPath(String path) {
        if (path != null) {
            servletPath = path;
            uploadForm.setAction(path);
        }
    }

    /**
     * set the status widget used to display the upload progress.
     */
    public void setStatusWidget(IUploadStatus stat) {
        if (stat == null) {
            return;
        }
        uploaderPanel.remove(statusWidget.getWidget());
        statusWidget = stat;
        if (!stat.getWidget().isAttached()) {
            uploaderPanel.add(statusWidget.getWidget());
        }
        statusWidget.getWidget().addStyleName(STYLE_STATUS);
        statusWidget.setVisible(false);
        statusWidget.addCancelHandler(cancelHandler);
        statusWidget.setStatusChangedHandler(statusChangedHandler);
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#setValidExtensions(java.lang.String[])
     */
    public void setValidExtensions(String... validExtensions) {
        if (validExtensions == null) {
            this.validExtensions = new String[0];
            return;
        }
        this.validExtensions = new String[validExtensions.length];
        validExtensionsMsg = "";
        for (int i = 0, j = 0; i < validExtensions.length; i++) {
            String ext = validExtensions[i];
            if (ext == null) {
                continue;
            }
            if (ext.charAt(0) != '.') {
                ext = "." + ext;
            }
            if (i > 0) {
                validExtensionsMsg += ", ";
            }
            validExtensionsMsg += ext;

            ext = ext.replaceAll("\\.", "\\\\.");
            ext = ".+" + ext;
            this.validExtensions[j++] = ext.toLowerCase();
        }
    }

    public void setValidExtensions(String ext) {
        setValidExtensions(ext.split("[, ]+"));
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#submit()
     */
    public void submit() {
        this.uploadForm.submit();
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUploader#setUploaded()
     */
    public void setUploaded(UploadedInfo info) {
        serverInfo = info;
        successful = true;
        statusWidget.setFileName(info.name);
        fileInput.setName(info.field);
        uploadFinished();
    }

    /*
     * (non-Javadoc)
     * @see gwtupload.client.IUpdateable#update()
     */
    public void update() {
        try {
            if (waitingForResponse) {
                return;
            }
            waitingForResponse = true;
            // Using a reusable builder makes IE fail because it caches the response
            // So it's better to change the request path sending an additional random parameter
            RequestBuilder reqBuilder = new RequestBuilder(RequestBuilder.GET,
                    composeURL("filename=" + fileInput.getName(), "c=" + requestsCounter++));
            reqBuilder.setTimeoutMillis(DEFAULT_AJAX_TIMEOUT);
            reqBuilder.sendRequest("get_status", onStatusReceivedCallback);
        } catch (RequestException e) {
            e.printStackTrace();
        }
    }

    /**
     * Method called when the file input has changed. This happens when the user selects a file. Override this method if
     * you want to add a customized behavior, but remember to call this in your function
     */
    protected void onChangeInput() {
        statusWidget.setStatus(Status.CHANGED);
        for (IUploader.OnChangeUploaderHandler handler : onChangeHandlers) {
            handler.onChange(this);
        }
    }

    /**
     * Method called when the file upload process has finished, or the file has been canceled or removed from the queue.
     * Override this method if you want to add a customized behavior, but remember to call this in your function.
     */
    protected void onFinishUpload() {
        for (IUploader.OnFinishUploaderHandler handler : onFinishHandlers) {
            handler.onFinish(this);
        }
    }

    /**
     * Method called when the file is added to the upload queue. Override this if you want to add a customized behavior,
     * but remember to call this from your method.
     */
    protected void onStartUpload() {
        for (IUploader.OnStartUploaderHandler handler : onStartHandlers) {
            handler.onStart(this);
        }
    }

    /**
     * Adds a file to the upload queue.
     */
    private void addToQueue() {
        statusWidget.setStatus(IUploadStatus.Status.QUEUED);
        statusWidget.setProgress(0, 0);
        if (!fileQueue.contains(fileInput.getName())) {
            onStartUpload();
            fileQueue.add(fileInput.getName());
        }
    }

    /**
     * Change the fileInput name, because the server uses it as an uniq identifier.
     */
    protected void assignNewNameToFileInput() {
        String fileInputName = (fileInputPrefix + "-" + Math.random()).replaceAll("\\.", "");
        fileInput.setName(fileInputName);
    }

    /**
     * Cancel upload process and show an error message to the user.
     */
    private void cancelUpload(String msg) {
        successful = false;
        uploadFinished();
        statusWidget.setStatus(IUploadStatus.Status.ERROR);
        statusWidget.setError(msg);
    }

    private String composeURL(String... params) {
        StringBuilder ret = new StringBuilder(getServletPath().replaceAll("[\\?&]+$", ""));
        String sep = ret.toString().contains("?") ? "&" : "?";
        for (String par : params) {
            ret.append(sep + par);
            sep = "&";
        }
        for (Entry<String, List<String>> e : Window.Location.getParameterMap().entrySet()) {
            ret.append(sep + e.getKey() + "=" + e.getValue().get(0));
        }
        ret.append(sep + "random=" + Math.random());
        return ret.toString();
    }

    private native JavaScriptObject getDataImpl(String url, String inputName, String fileName, String baseName,
            String serverResponse, String serverMessage, String status, int size) /*-{
                                                                                  return {
                                                                                  url : url,
                                                                                  name : inputName,
                                                                                  filename : fileName,
                                                                                  basename : baseName,
                                                                                  response : serverResponse,
                                                                                  message : serverMessage,
                                                                                  status : status,
                                                                                  size : size
                                                                                  };
                                                                                  }-*/;

    private boolean isTheFirstInQueue() {
        return fileQueue.size() > 0 && fileQueue.get(0).equals(fileInput.getName());
    }

    private void parseAjaxResponse(String responseTxt) {
        if (responseTxt == null) {
            return;
        }

        String error = null;
        Document doc = null;
        try {
            doc = XMLParser.parse(responseTxt);
            error = Utils.getXmlNodeValue(doc, "error");
        } catch (Exception e) {
            if (responseTxt.toLowerCase().matches("error")) {
                error = i18nStrs.uploaderServerError() + "\nAction: " + getServletPath() + "\nException: "
                        + e.getMessage() + responseTxt;
            }
        }

        if (error != null) {
            successful = false;
            cancelUpload(error);
            return;
        } else if (Utils.getXmlNodeValue(doc, TAG_WAIT) != null) {
            if (serverResponse != null) {
                log("server response received, cancelling the upload " + getFileName() + " " + serverResponse,
                        null);
                successful = true;
                uploadFinished();
            }
        } else if (Utils.getXmlNodeValue(doc, TAG_CANCELED) != null) {
            log("server response is: canceled " + getFileName(), null);
            successful = false;
            canceled = true;
            uploadFinished();
            return;
        } else if (Utils.getXmlNodeValue(doc, TAG_FINISHED) != null) {
            log("server response is: finished " + getFileName(), null);
            successful = true;
            if (onSubmitComplete) {
                log("response from server has been received", null);
                uploadFinished();
            }
            return;
        } else if (Utils.getXmlNodeValue(doc, TAG_PERCENT) != null) {
            lastData = now();
            int transferredKB = Integer.valueOf(Utils.getXmlNodeValue(doc, TAG_CURRENT_BYTES)) / 1024;
            int totalKB = Integer.valueOf(Utils.getXmlNodeValue(doc, TAG_TOTAL_BYTES)) / 1024;
            statusWidget.setProgress(transferredKB, totalKB);
            log("server response transferred  " + transferredKB + "/" + totalKB + " " + getFileName(), null);
            return;
        } else {
            log("incorrect response: " + getFileName() + " " + responseTxt, null);
        }

        if (uploadTimeout > 0 && now() - lastData > uploadTimeout) {
            successful = false;
            cancelUpload(i18nStrs.uploaderTimeout());
            try {
                sendAjaxRequestToCancelCurrentUpload();
            } catch (Exception e) {
            }
        }
    }

    /**
     * remove a file from the upload queue.
     */
    private void removeFromQueue() {
        fileQueue.remove(fileInput.getName());
    }

    private String removeHtmlTags(String message) {
        return message.replaceAll("<[^>]+>", "");
    }

    private void sendAjaxRequestToCancelCurrentUpload() throws RequestException {
        RequestBuilder reqBuilder = new RequestBuilder(RequestBuilder.GET, composeURL("cancel=true"));
        reqBuilder.sendRequest("cancel_upload", onCancelReceivedCallback);
    }

    private void sendAjaxRequestToDeleteUploadedFile() throws RequestException {
        RequestBuilder reqBuilder = new RequestBuilder(RequestBuilder.GET, composeURL("remove=" + getInputName()));
        reqBuilder.sendRequest("remove_file", onDeleteFileCallback);
    }

    /**
     * Sends a request to the server in order to get the blobstore path. When the response with the session comes, it
     * submits the form.
     */
    private void sendAjaxRequestToGetBlobstorePath() throws RequestException {
        RequestBuilder reqBuilder = new RequestBuilder(RequestBuilder.GET, getServletPath());// composeURL("blobstore=true"));
        reqBuilder.setTimeoutMillis(DEFAULT_AJAX_TIMEOUT);
        reqBuilder.sendRequest("blobstore", onBlobstoreReceivedCallback);
    }

    /**
     * Sends a request to the server in order to get the session cookie, when the response with the session comes, it
     * submits the form. This is needed because this client application usually is part of static files, and the server
     * doesn't set the session until dynamic pages are requested. If we submit the form without a session, the server
     * creates a new one and send a cookie in the response, but the response with the cookie comes to the client at the
     * end of the request, and in the meanwhile the client needs to know the session in order to ask the server for the
     * upload status.
     */
    private void sendAjaxRequestToValidateSession() throws RequestException {
        // Using a reusable builder makes IE fail
        RequestBuilder reqBuilder = new RequestBuilder(RequestBuilder.GET, composeURL("new_session=true"));
        reqBuilder.setTimeoutMillis(DEFAULT_AJAX_TIMEOUT);
        reqBuilder.sendRequest("create_session", onSessionReceivedCallback);
    }

    /**
     * Called when the uploader detects that the upload process has finished: - in the case of submit complete. - in the
     * case of error talking with the server.
     */
    private void uploadFinished() {
        removeFromQueue();
        finished = true;
        uploading = false;
        updateStatusTimer.cancel();
        statusWidget.setVisible(false);

        if (successful) {
            if (avoidRepeatedFiles) {
                if (!fileDone.contains(getFileName())) {
                    fileDone.add(getFileName());
                }
                statusWidget.setStatus(IUploadStatus.Status.SUCCESS);
            } else {
                statusWidget.setStatus(IUploadStatus.Status.SUCCESS);
            }
        } else if (canceled) {
            statusWidget.setStatus(IUploadStatus.Status.CANCELED);
        } else {
            statusWidget.setStatus(IUploadStatus.Status.ERROR);
        }

        onFinishUpload();
    }

    private boolean validateExtension(String filename) {
        if (filename == null || filename.length() == 0) {
            return !avoidEmptyFile;
        }
        boolean valid = Utils.validateExtension(validExtensions, filename);
        if (!valid) {
            finished = true;
            statusWidget.setStatus(Status.INVALID);
            statusWidget.setError(i18nStrs.uploaderInvalidExtension() + validExtensionsMsg);
        }
        return valid;
    }

}