commandButton for removing images from p:galleria - jsf

Question

I am using Primefaces 5.0.2 with Glassfish 4 (Mojarra 2.2.0).
I've been trying to add a command button to delete/remove the selected image in a p:galleria component. I tried adding a button within the galleria component like this:
<p:galleria id="images" value="#{someBean.images}" var="image">
<p:graphicImage value="#{image}"/>
<p:commandButton icon="ui-icon-trash" title="Delete #{image}" style="position:absolute; top:0; right:0; z-index:10;"
actionListener="#{someBean.deleteImage(image)}"
update="growl images" />
</p:galleria>
I can display the image path fine within the button, but passing the image parameter in the EL Expression #{someBean.deleteImage(image)} does not work as expected.
The issue I have is that when deleteImage is called the image parameter (String) is always empty instead of containing the image name. However, title="Delete #{image}" displays fine, so I suspect image isn't resolved correctly within the actionListener or action attributes.
If I enter a literal string in the xhtml, e.g. #{someBean.deleteImage('deleteme')} it is passed correctly. Passing null also gives an empty string.
someBean.images is a List<String> (image paths).
I am at a loss :/ could anyone point me in the right direction? Is this a bug or am I doing something wrong?
I have also thought about adding a button outside the galleria component, but I am unclear as to how to determine the selected image without having to modify the p:galleria component.
There is also an unanswered question about this (1yr old) How to get the selected image from <p:galleria
Update:
Appending "test" to image using ui:param or c:set will actually give me the string "test" within the deleteImage method, but the h:outputText component correctly renders the value of image with "test" appended. This suggests to me that they are rendered at different times - and the commandButton is rendered at a time when image is null?
<p:galleria id="images" value="#{someBean.images}" var="image">
<p:graphicImage value="#{image}"/>
<ui:param name="img" value="#{image}test"/>
<h:outputText value="#{img}"/>
<p:commandButton icon="ui-icon-trash" title="Delete #{image}" style="position:absolute; top:0; right:0; z-index:10;"
actionListener="#{someBean.deleteImage(img)}"/>
</p:galleria>
Update 2
This could be related to a similar issue in Primefaces Extensions - maybe it is a bug after all. http://forum.primefaces.org/viewtopic.php?f=14&t=39992
I also started a thread in the PF forum: http://forum.primefaces.org/viewtopic.php?f=3&t=40055

Answer 1

<p:galleria id="photoGalleria"
panelHeight="400"
panelWidth="450"
widgetVar="photoGalleriaWidgetVar"
style="width: 100%;"
autoPlay="false"
value="#{partEditBean.selectedPart.partPictures}" var="img">
<p:panelGrid columns="1" styleClass="wf" style="text-align: center;">
<p:commandButton id="delete_pic_button"
update="#form"
value="#{msg['part_view.delete']}" process="#this"
actionListener="#{partImageEditBean.deleteListener}">
<f:param name="pic_id" value="#{img.picId}"/>
</p:commandButton>
</p:panelGrid>
<p:graphicImage styleClass="wf galleriaOver" value="#{img.picUrlPath}"
title="#{partEditBean.selectedPart.partTreeNode.partPathName}"
onclick="window.open('#{img.picUrlPath}','_blank');"/>
</p:galleria>
FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("pic_id")