[英]Java Wicket AjaxLink and RequestHandler - How to?
Usage scenario: The user clicks on a link on a web site do get a dynamically generated PDF in both languages: German and English. 使用方案:用户单击网站上的链接,会获得两种语言(德语和英语)的动态生成的PDF。
This code works. 此代码有效。 generateCouponPdfOnClick creates a ResourceStreamRequestHandler containing a pdf file. generateCouponPdfOnClick创建一个包含pdf文件的ResourceStreamRequestHandler。
Link<Void> generatePdf = new Link<Void>("generatePdf") {
@Override
public void onClick() {
ResourceStreamRequestHandler requestHandler = generateCouponPdfOnClick(coupon, PDFLanguage.GERMAN);
getRequestCycle().scheduleRequestHandlerAfterCurrent(requestHandler);
}
};
Now I want to change the code to get a popup (Wicket Modalwindow, here class PdfDialogPage) where the user can select a language (German/English) for the PDF by klicking on one of the two buttons. 现在,我想更改代码以获取一个弹出窗口(Wicket Modalwindow,此处为PdfDialogPage类),用户可以通过单击两个按钮之一来为PDF选择一种语言(德语/英语)。 If the user clicks a button, the ModalWindow should close and the PDF should be build and displayed. 如果用户单击一个按钮,则应该关闭ModalWindow,并且应该构建并显示PDF。
Here is the modified code: The variable pdflanguageanguage contains the selected language and is set by the PdfDialogPage using the PageReferenz 这是修改后的代码:变量pdflanguageanguage包含选定的语言,由PdfDialogPage使用PageReferenz设置
AjaxLink<Void> generatePdf = new AjaxLink<Void>("generatePdf") {
@Override
public void onClick(final AjaxRequestTarget target) {
modalWindow.setPageCreator(() -> {
return new PdfDialogPage(getPage().getPageReference(), modalWindow);
});
modalWindow.setWindowClosedCallback((AjaxRequestTarget target1) -> {
ResourceStreamRequestHandler requestHandler = generateCouponPdfOnClick(coupon, pdflanguageanguage);
getRequestCycle().scheduleRequestHandlerAfterCurrent(requestHandler);
});
modalWindow.show(target);
};
When I click the link, the modalwindow opens. 当我单击链接时,将打开模态窗口。 I select the language, eg English, and the modalWindow closes while writing "English" to the variable pdflanguageanguage. 我选择语言,例如英语,然后在将“英语”写入变量pdflanguageanguage时关闭modalWindow。 Than nothing more happens ... and the PDF is not generated. 仅此而已...没有生成PDF。 The Wicket Ajax Debug Window tells me the follogwing logs: Wicket Ajax调试窗口告诉我以下日志:
</head>]]></header-contribution><evaluate><![CDATA[(function(){var settings = {"minWidth":200,"minHeight":200,"className":"w_blue","width":400,"height":100,"resizable":true,"src":"./wicket/page?6","mask":"semi-transparent","autoSize":false,"unloadConfirmation":true,"onClose":function() { Wicket.Ajax.ajax({"u":"./overviewCoupons?5-1.1-panel-modalWindow","c":"modalWindowb0"}); },"onCloseButton":function() { Wicket.Ajax.ajax({"u":"./overviewCoupons?5-1.0-panel-modalWindow","c":"modalWindowb0"});; return false; }};window.setTimeout(function(){
Wicket.Window.create(settings).show();
}, 0);
})();]]></evaluate></ajax-response>
INFO: returned focused element: javascript:;
INFO: returned focused element: javascript:;
INFO: Response processed successfully.
INFO: refocus last focused component not needed/allowed
INFO: focus removed from generatePdf5
INFO: focus set on _wicket_window_3
INFO: focus set on undefined
INFO: focus removed from undefined
ERROR: Wicket.Ajax.Call.failure: Error while parsing response: Error: Invalid XML: %PDF-1.4 %
1 0 obj
<<
/Creator (Apache FOP Version 2.3)
/Producer (Apache FOP Version 2.3)
/CreationDate (D:20180808160110+02'00')
I believe that there is a problem between Ajax and "getRequestCycle().scheduleRequestHandlerAfterCurrent(requestHandler);". 我相信Ajax与“ getRequestCycle()。scheduleRequestHandlerAfterCurrent(requestHandler);”之间存在问题。 How do I use these together. 我如何一起使用这些。 So I reduced code to: 所以我将代码简化为:
AjaxLink<Void> generatePdf = new AjaxLink<Void>("generatePdf") {
@Override
public void onClick(final AjaxRequestTarget target) {
ResourceStreamRequestHandler requestHandler = generateCouponPdfOnClick(coupon, PDFLanguage.ENGLISH);
getRequestCycle().scheduleRequestHandlerAfterCurrent(requestHandler);
}
};
When I know click the AjaxLink, nothing happens but I get the same Ajax Log Error Output. 当我知道单击AjaxLink时,什么都没有发生,但是我得到了相同的Ajax日志错误输出。
How do I use AjaxLink together with ResourceStreamRequestHandler? 如何将AjaxLink与ResourceStreamRequestHandler一起使用?
I solved a similar use case like you have in this way. 我以这种方式解决了类似的用例。
You need the Java class AjaxDownload
from here 您需要Java类AjaxDownload
从这里
Alternatively you can use my variation which takes a FileResourceStream
as input. 或者,您可以使用将FileResourceStream
用作输入的变量。
import lombok.extern.slf4j.Slf4j;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.behavior.AbstractAjaxBehavior;
import org.apache.wicket.request.handler.resource.ResourceStreamRequestHandler;
import org.apache.wicket.request.resource.ContentDisposition;
import org.apache.wicket.util.resource.FileResourceStream;
/**
* @author Sven Meier
* @author Ernesto Reinaldo Barreiro (reiern70@gmail.com)
* @author Jordi Deu-Pons (jordi@jordeu.net)
*/
@Slf4j
public class AJAXDownload extends AbstractAjaxBehavior {
private boolean addAntiCache;
private FileResourceStream fileResourceStream;
private String fileName;
public AJAXDownload() {
this(true);
}
public AJAXDownload(boolean addAntiCache) {
super();
this.addAntiCache = addAntiCache;
}
/**
* Call this method to initiate the download.
*/
public void initiate(AjaxRequestTarget target, FileResourceStream fileResourceStream, String fileName) {
this.fileResourceStream= fileResourceStream;
this.fileName = fileName;
String url = getCallbackUrl().toString();
if (addAntiCache) {
url = url + (url.contains("?") ? "&" : "?");
url = url + "antiCache=" + System.currentTimeMillis();
}
// the timeout is needed to let Wicket release the channel
target.appendJavaScript("setTimeout(\"window.location.href='" + url + "'\", 100);");
}
public void onRequest() {
try{
ResourceStreamRequestHandler handler = new ResourceStreamRequestHandler(fileResourceStream, fileName);
handler.setContentDisposition(ContentDisposition.ATTACHMENT);
getComponent().getRequestCycle().scheduleRequestHandlerAfterCurrent(handler);
} catch (Exception e){
log.error("Error while trying to download", e);
onErrorOccurred();
}
}
protected void onErrorOccurred(){}
}
How to use? 如何使用?
you have to add the AjaxDownload to your Form 您必须将AjaxDownload添加到您的表单中
form.add(ajaxDownload = new AJAXDownload());
in your onSubmit from your AjaxLink you can call: 在AjaxLink的onSubmit中,您可以调用:
File yourPdfFile = //create your pdf file; final FileResourceStream resourceStream= new FileResourceStream(yourPdfFile); ajaxDownload.initiate(target, resourceStream, "yourPDF.pdf");
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.