Custom File Download with reRender using commandbutton

[carlhowarth]

Hello there,

I have an a4j:commandButton that generates an Excel file on the fly and downloads the file via the user's browser by writing the the response's outputstream.

The file downloads successfully if I use a h:commandButton, however I want to reRender a historical list of downloaded files after the new file is created. If I use an a4j:commandButton, the file is generated but the whole page is rerendered with an interpretation of the Excel file, which is all nonsense!

Can anybody point me in the right direction to perform this task cleanly?

Any advice would be gratefully received. Thanks, Carl

[harnishg]

Not to be all doom and gloom, but to my knowledge, there is no way for this to work.

When you generate the Excel file, you are corrupting the View State. IE: The function that generates the Excel output is probably using FacesContext.responseComplete().

It is the same problem I'm having for a month. However I'm using h:commandButton ... and trying to use a4j:support'ed drop downs afterwards ... and getting the Excel file gibberish then ... however if I use a4j:commandButton, I get the gibberish immediately.

If you are interested, this is what I wrote up:
http://jboss.com/index.html?module=bb&op=viewtopic&t=107693

[alexsmirnov]

This use-case must be divided ino two parts : update page content and open a Excel spreadshit. You can send ajax request by a4j component, and redirect to download generated file in a 'oncomplete' method.

[harnishg]

Is one not going to encounter the problem again when they click on another A4J command button?

If not, how exactly does this work ... something like:

<a4j:commandButtion actionListener="#{bean.Update}" oncomplete="#{bean.saveExcel}" />

[ilya_shaikovsky]

you need to define JS function to be called after request complete in oncomplete attribute.

[harnishg]

Right so something like:

<a4j:jsFunction name="saveExcel" actionListener="#{bean.saveExcel}" />

<a4j:commandButton actionListener="#{Bean.Update}" oncomplete="saveExcel();" />

[carlhowarth]

I've tried this approach, and unfortunately the same thing is happening - the table updates because of the rerender, however when the function runs, it still runs in an ajax request, therefore I'm presented with gobbledegook! :-(