StreamedContent not getting populated beyond RENDER_RESPONSE [duplicate] - jsf

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Display dynamic image from database or remote source with p:graphicImage and StreamedContent
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Backing beans (#ManagedBean) or CDI Beans (#Named)?
(5 answers)
Closed 2 years ago.
I'm relatively new to JSF and Primefaces.
I'm trying to build a document viewer that would display tiff, jpeg and pdf.
My UI has a left and a right layout.
Left layout contains a vertical grid of thumbnails of the docs.
User clicks on a thumbnail, and the right layout displays the doc (either via a p:graphicImage or via a p:documentViewer, depending on the thumbnail clicked).
For tiffs, I'm converting the image into PNG and then displaying (both, for the thumbnail and the main display).
For multi-page tiff files, I show only the first page as the left side thumbnail...and for the main display, I give Next and Previous buttons to navigate through the pages. The UI is something like this:
The problem:
When I click on the thumbnails, the backing method gets invoked twice as expected (the second call returning the StreamedContent with the actual data).
However, when I click the Prev and Next buttons, the same backing method is getting called only once -- just for phaseid=RENDER_RESPONSE.
(eventually, this causes the bean method to return only an empty StreamedContent and not one carrying the actual image data...so I don't get to see the other pages of the tiff)
The form:
<h:form id="mainform">
<p:layout fullPage="true" style="width:100%;height:100%">
<p:layoutUnit position="west" style="width:15%;overflow:scroll;" resizable="true">
<p:panelGrid header="Thumbnails" columns="1" class="thumbcell" >
<p:repeat value="#{viewerController.docIds}" var="docId">
<p:panelGrid style="padding:0px !important;" columns="1" rendered="#{docId.contains('img')}" >
<p:commandLink update=":mainform:renderpanel" action="#{viewerController.setSelectedDocId(docId)}">
<p:graphicImage value="#{viewerController.imageDocumentStream}" style="height: 100px; width: 90px; border: none !important; padding:0px;background: lightgrey;"
alt="#{viewerController.getDocumentName(docId)}">
<f:param name="id" value="#{docId}" />
</p:graphicImage>
</p:commandLink>
<p:outputLabel value="#{viewerController.getDocumentName(docId)}"/>
</p:panelGrid>
<p:panelGrid style="padding:0px !important;" columns="1" rendered="#{docId.contains('tif')}">
<p:commandLink update=":mainform:renderpanel" action="#{viewerController.setSelectedDocId(docId)}">
<p:graphicImage value="#{viewerController.tifDocumentStream}" style="height: 100px; width: 90px; border: none !important; padding:0px;background: lightgrey;"
alt="#{viewerController.getDocumentName(docId)}">
<f:param name="id" value="#{docId}" />
<f:param name="forThumbnail" value="true" />
</p:graphicImage>
</p:commandLink>
<p:outputLabel value="#{viewerController.getDocumentName(docId)}"/>
</p:panelGrid>
<p:panelGrid style="padding:0px !important;" columns="1" rendered="#{docId.contains('pdf')}">
<p:commandLink update=":mainform:renderpanel" action="#{viewerController.setSelectedDocId(docId)}">
<p:graphicImage value="#{viewerController.pdfFirstPageDocumentStream}" style="height: 100px; width: 90px; border: none !important; padding:0px;background: lightgrey;"
alt="#{viewerController.getDocumentName(docId)}">
<f:param name="id" value="#{docId}" />
</p:graphicImage>
</p:commandLink>
<p:outputLabel value="#{viewerController.getDocumentName(docId)}"/>
</p:panelGrid>
</p:repeat>
</p:panelGrid>
</p:layoutUnit>
<p:layoutUnit position="center" style="width:85%;">
<p:panel id="renderpanel">
<p:panelGrid style="padding:0px !important;" columns="1" rendered="#{viewerController.currentDocId.contains('tif')}">
<p:outputLabel value="#{viewerController.getDocumentName(viewerController.currentDocId)}"/>
<p:panelGrid style="padding:0px !important;" columns="3" id="tifPanelGrid">
<p:commandButton update=":mainform:renderpanel" action="#{viewerController.navigateTif('prev', viewerController.currentDocId)}"
id="prevButton" value="Prev" title="Previous page" disabled="#{viewerController.prevButtonDisable}"/>
<p:graphicImage rendered="#{viewerController.render}" id="tifPanel" value="#{viewerController.tifDocumentStream}" style="height: 600px; width: 800px; border: none !important; padding:0px;background: lightgrey;"
alt="#{viewerController.getDocumentName(viewerController.currentDocId)}">
<f:param name="id" value="#{viewerController.currentDocId}" />
<f:param name="forThumbnail" value="false" />
</p:graphicImage>
<p:commandButton update=":mainform:renderpanel" action="#{viewerController.navigateTif('next', viewerController.currentDocId)}"
id="nextButton" value="Next" title="Next page" disabled="#{viewerController.nextButtonDisable}"/>
</p:panelGrid>
</p:panelGrid>
<p:panelGrid style="padding:0px !important;" columns="1" rendered="#{viewerController.currentDocId.contains('img')}">
<p:outputLabel value="#{viewerController.getDocumentName(viewerController.currentDocId)}"/>
<p:graphicImage value="#{viewerController.imageDocumentStream}" style="height: 600px; width: 800px; border: none !important; padding:0px;background: lightgrey;"
alt="#{viewerController.getDocumentName(viewerController.currentDocId)}">
<f:param name="id" value="#{viewerController.currentDocId}" />
</p:graphicImage>
</p:panelGrid>
<p:panelGrid style="padding:0px !important;" columns="1" rendered="#{viewerController.currentDocId.contains('pdf')}">
<p:outputLabel value="#{viewerController.getDocumentName(viewerController.currentDocId)}"/>
<pe:documentViewer height="600" width="800" value="#{viewerController.pdfDocumentStream}" >
<f:param name="id" value="#{viewerController.currentDocId}" />
</pe:documentViewer>
</p:panelGrid>
</p:panel>
</p:layoutUnit>
</p:layout>
</h:form>
The controller class is annotated with these two:
javax.annotation.ManagedBean
javax.enterprise.context.SessionScoped
The backing method in the controller class, that is not getting invoked twice:
public StreamedContent getTifDocumentStream() throws IOException {
FacesContext context = FacesContext.getCurrentInstance();
if (context.getCurrentPhaseId() == PhaseId.RENDER_RESPONSE ) {
return new DefaultStreamedContent();
} else {
String id = context.getExternalContext().getRequestParameterMap().get("id");
String forThumbnail = context.getExternalContext().getRequestParameterMap().get("forThumbnail");
Doc doc = tifDocMap.get(id);
InputStream is = this.convertTiffToPng(doc, forThumbnail);
return new DefaultStreamedContent(is);
}
}
I'm on this combination: SpringBoot + JoinFaces + PF 6.2
Can any body please advise what I'm doing wrong?
An alternate way I'm considering, to achieve the purpose:
May be, turn the pages of the tiff to individual PNGs beforehand, and then use galleria ...but it would be nice if I could get galleria to work with StreamedContent of each page dynamically.