Controlling the onClick or onSucess events from bean (primefaces)?

Question

I need to show in another tab the generate Report with bean method (bean.generateReporte()). And show a message when the Report is not possible to be generated (not data is found according to criteria).

my first code in the .xhtml was:

<p:commandButton id="printDeliveryList" label="Generate Delivery List" styleClass="btn-success"
     style="float:left" icon="fa fa-print" 
     action="#{bean.generateReporte()}"
     onclick="this.form.target = '_blank'"
     ajax="false"
 />

I was reading this question How to prevent commandButton from executing action when onclick method return false and this question How to call JS function on click of JSF button and block page reload/navigation? and this post https://www.adictosaltrabajo.com/2011/09/14/primefaces-client-side-ajax-events/ And this documentation https://www.primefaces.org/showcase/ui/misc/requestContext.xhtml

I was thinking in onsuccess event.

Here my code later....

In the bean side I have:

public void generateReporte() {
    // blabla
    if (success) {
        addGeneratedToCallback(true);
    } else {
        addGeneratedToCallback(false);
    }
}

private void addGeneratedToCallback(boolean value) {
    PrimeFaces.current().ajax().addCallbackParam("generated", value);
}

In the .xhtml side

<script type="text/javascript">
    function handleComplete(xhr, status, args) {
        if (args.validationFailed) {
            PrimeFaces.debug("Validation Failed");
        } else {
            if (args.generated) {
                // open a new tab in the browser
                //window.open(this.form.target = '_blank');
                form.target = '_blank';
            } else {
                // show message
            }
        }
    }
</script>


<p:commandButton id="printListaEntrega" label="Generar Lista de Entrega" styleClass="btn-success"
                 style="float:left" icon="fa fa-print" 
                 action="#{bean.generateReporte()}"
                 ajax="false"
                 oncomplete="handleComplete(xhr, status, args)"
                 />

The Result of my code

With ajax="false" I got this when the generation of Report is not possible.

When I remove ajax="false" from the p:commandButton and the report is generated I got. (Not open the new tab in browser And Can't download the report)

Is it possible to set contitional ajax="bean.someMethodOrProperty"?

Answer 1

In the .xhtml

<p:commandButton id="printDeliveryList" label="Generate Delivery List" styleClass="btn-success"
                 style="float:left" icon="fa fa-print" 
                 action="#{bean.generateReport()}"
                 oncomplete="if (args &amp;&amp; !args.validationFailed) {PF('download').jq.click();PF('openNewTab').jq.click() }"
                 />
<p:commandButton widgetVar="download" styleClass="ui-helper-hidden" 
                 action="#{bean.downloadFile()}" ajax="false" />
<p:commandButton widgetVar="openNewTab" styleClass="ui-helper-hidden" 
                 action="#{bean.openInNewTab()}" 
                 onclick="this.form.target = '_blank'" ajax="false" />

in the bean

public void generateReport() {
    // blabla
    if (success) {
        bytesToBeDownload = getBytesOfReport();
        nameOfFile = getNameOfReport() + ".pdf";
    } else {
        Faces.validationFailed();
    }
}


public void downloadFile() {
    try {
        // byte[] bytesToBeDownload = ....
        org.omnifaces.util.Faces.sendFile(bytesToBeDownload, nameOfFile, true);
    } catch (IOException e) {
        //Exception handling
    }
}


public void openInNewTab() {
    try {
        byte[] bytes = bytesToBeDownload;
        ByteArrayOutputStream baos = new ByteArrayOutputStream(bytes.length);
        baos.write(bytes, 0, bytes.length);
        buildResponse(baos, "application/pdf");
    } catch (Exception e) {
        //Exception handling
    }
}


private static void buildResponse(ByteArrayOutputStream out, String contentType) {

    ByteArrayInputStream input = null;
    BufferedOutputStream output = null;

    try {

        input = new ByteArrayInputStream(out.toByteArray());
        int bufferSize = out.toByteArray().length;

        FacesUtils.getHttpServletResponse().reset();
        FacesUtils.getHttpServletResponse().setHeader("Content-Type", contentType);
        FacesUtils.getHttpServletResponse().setHeader("Content-Length", String.valueOf(bufferSize));
        output = new BufferedOutputStream(FacesUtils.getHttpServletResponse().getOutputStream(), bufferSize);

        byte[] buffer = new byte[bufferSize];
        int length;
        while ((length = input.read(buffer)) > 0) {
            output.write(buffer, 0, length);
        }
        output.flush();

    } catch (Exception ex) {
        //Exception handling
    } finally {
        try {
            output.close();
            input.close();
        } catch (Exception ex) {
        //Exception handling
        }
    }
    FacesUtils.getFacesContext().responseComplete();
}