package org.wicketstuff.html5.fileapi;
import java.util.Calendar;
import org.apache.wicket.Component;
import org.apache.wicket.ajax.AjaxEventBehavior;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.attributes.AjaxCallListener;
import org.apache.wicket.ajax.attributes.AjaxRequestAttributes;
import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.markup.head.JavaScriptHeaderItem;
import org.apache.wicket.markup.html.form.upload.FileUploadField;
import org.apache.wicket.request.IRequestParameters;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.resource.JavaScriptResourceReference;
import org.apache.wicket.request.resource.ResourceReference;
import org.apache.wicket.util.string.StringValue;
/**
* <p>
* A {@link Behavior} that can be used on {@link FileUploadField}-s to receive ajax callback with
* detailed information about the chosen files when an event occurs (default: "onchange"). When the
* ajax call is triggered (for example user selects files for upload) the metadata about the file(s)
* (name, size, type, last modify date) is sent with the ajax call to the server (so the content is
* not). Subclasses of this class can respond to this event by implementing the
* {@link #onEvent(AjaxRequestTarget, FileList)} method.
* </p>
* <p>
* Works with single or multiple enabled file inputs.
* </p>
* <p>
* Note that this behaviour only works with browsers implementing the Html5 FileApi (Chrome 11,
* Firefox 4). It does not change or break browsers not implementing the api.
* </p>
*
* @author akiraly
*/
public abstract class FileFieldChangeBehavior extends AjaxEventBehavior
{
private static final long serialVersionUID = -3716216245965207135L;
protected static final ResourceReference JAVASCRIPT_REF = new JavaScriptResourceReference(
FileFieldChangeBehavior.class, "fileapi.js");
/**
* Default maximum number of files that are processed from the ajax request: 100.
*/
public static final int DEFAULT_MAX_NUM_OF_FILES = 100;
private final int maxNumOfFiles;
/**
* Default constructor: the monitored event is "onchange" and maxNumOfFiles is
* {@link #DEFAULT_MAX_NUM_OF_FILES}.
*/
public FileFieldChangeBehavior()
{
this(DEFAULT_MAX_NUM_OF_FILES);
}
/**
* Constructor. The monitored event is "onchange".
*
* @param maxNumOfFiles
* maximum number of files that are processed from the ajax request, non-negative
*/
public FileFieldChangeBehavior(int maxNumOfFiles)
{
this("onchange", maxNumOfFiles);
}
/**
* Constructor.
*
* @param event
* event for which the ajax call is triggered, not-null
* @param maxNumOfFiles
* maximum number of files that are processed from the ajax request, non-negative
*/
protected FileFieldChangeBehavior(String event, int maxNumOfFiles)
{
super(event);
this.maxNumOfFiles = maxNumOfFiles;
}
@Override
public void renderHead(Component component, IHeaderResponse response)
{
super.renderHead(component, response);
response.render(JavaScriptHeaderItem.forReference(JAVASCRIPT_REF));
}
@Override
protected void onEvent(AjaxRequestTarget target)
{
IRequestParameters parameters = RequestCycle.get().getRequest().getPostParameters();
int num = parameters.getParameterValue("num").toInt();
if (num > maxNumOfFiles)
num = maxNumOfFiles;
FileList fileList = new FileList(num);
for (int fi = 0; fi < num; fi++)
{
String prefix = "file[" + fi + "].";
String name = parameters.getParameterValue(prefix + "name").toString();
long size = parameters.getParameterValue(prefix + "size").toLong();
String type = parameters.getParameterValue(prefix + "type").toString();
StringValue lastModifiedTimeStr = parameters.getParameterValue(prefix +
"lastModifiedTime");
Calendar lastModifiedDate;
if (!lastModifiedTimeStr.isNull())
{
long lastModifiedTime = lastModifiedTimeStr.toLong();
lastModifiedDate = Calendar.getInstance();
lastModifiedDate.setTimeInMillis(lastModifiedTime);
}
else
lastModifiedDate = null;
fileList.set(fi, new Html5File(name, size, type, lastModifiedDate));
}
onEvent(target, fileList);
}
/**
* Called during the ajax callback.
*
* @param target
* wicket object representing the ajax response, not-null
* @param fileList
* list of files chosen in the upload field, not-null
*/
protected abstract void onEvent(AjaxRequestTarget target, FileList fileList);
@Override
protected void updateAjaxAttributes(AjaxRequestAttributes attributes)
{
super.updateAjaxAttributes(attributes);
attributes.setMethod(AjaxRequestAttributes.Method.POST);
AjaxCallListener ajaxCallListener = new AjaxCallListener();
ajaxCallListener.onPrecondition("return Wicketstuff.fileapi.supports(this)&&Wicket.$('" +
getComponent().getMarkupId() + "') != null;");
attributes.getDynamicExtraParameters().add("return Wicketstuff.fileapi.fileFieldToPostBody(Wicket.$(attrs.c));");
}
/**
* Returns the configured max.
*
* @return maximum number of files that are processed from the ajax request, non-negative
*/
public int getMaxNumOfFiles()
{
return maxNumOfFiles;
}
}