Unable to disable <p:commandButton> via ajax - jsf

Question

I want to disable the button in case there is no value in the input text something like this:
<p:autoComplete id="ac" value="#{bean.selectedNet}"
completeMethod="#{bean.complete}"
minQueryLength="0" size="3">
<p:ajax event="itemSelect" update="genButton" listener="#{bean.handleNetChange}"/>
<p:ajax process="#this" update="genButton" />
</p:autoComplete>
<p:selectManyCheckbox id="en" layout="pageDirection" value="#{bean.selectedEntity}">
<f:selectItems value="#{bean.entityList}"/>
<p:ajax update="genButton" listener="#{bean.handleNetChange}"/>
</p:selectManyCheckbox>
<p:commandButton id="genButton" value="Generate Files"
widgetVar="startButton1"
disabled="#{bean.disableButton}"
actionListener="#{bean.generate}"
onclick="PrimeFaces.monitorDownload(showStatus, hideStatus)"
ajax="false">
<p:fileDownload value="#{bean.streamedContent}"/>
</p:commandButton>
Methods:
public void handleNetChange() {
if (!StringUtils.isBlank(selectedNet) && !selectedEntity.isEmpty()) {
disableButton = false;
} else {
disableButton = true;
}
}
public List<String> complete(String query) {
List<String> results = new ArrayList<String>();
if (StringUtils.isBlank(query)) {
selectedNet = query;
disableButton = true;
} else {
....
}
return results;
}
While the itemSelect event is working perfectly the second one is not. I can see the call to the complete method in the bean but the button is not updated
Any advise?

Answer 1

Seems like you can't force update just with <p:ajax process="#this" update="genButton" />.
I would try to update the button directly from the bean.
Since you are using primefaces you can use RequestContext; try to add this line to your complete method :
RequestContext.getCurrentInstance().addPartialUpdateTarget("genButton");
If you don't use prependId="false" on your wrapping form, you might need to specify the full path to the button e.g.:
RequestContext.getCurrentInstance().addPartialUpdateTarget("fooForm:genButton");

Answer 2

If you want to use disabled, do not use rendered property on command button.
<p:commandButton id="buttonId"
actionListener="#{controller.function}"
value="#{controller.label}"
disabled="#{controller.disableButton}" rendered="#{controller.renderButton}" />
After removing rendered, button gets disabled without any issues.