This can be done e.g. by a Facelets Decorator using <ui:insert> and I have used this in a number of places.<\/p>\n
However, in one case, I wanted to make a complex treeBrowser custom tag switchable between editable mode and readonly using just a single flag passed as an attribute. Note that I did not want to switch it dynamically at run time \u2013 I just re-used the tag in a number of places and some were editable and some were not. As this switch involved a number of changes in the tag, it was convenient to drive them all from a single flag.<\/p>\n
In addition, whilst I could have used a decorator for this, I already had 2 versions of the tag each decorating a base version, where each version was used to browse completely different tree structured data in the application which was all handled polymorphically. Using decorators for readonly\/editable as well would have multiplied up the variants to 4, which was undesirable. By using a single EL flag, I was able to make all the switching entirely in the base custom tag which was a real help here.<\/p>\n
Anyway<\/em><\/strong> \u2013 to discuss the real point of the post \u2013 to achieve my goal I needed to conditionally include columns for a <p:dataTable>. Using <ui:fragment> to do this does not work as <ui:fragment> creates a new component in the JSF tree which is not a column, and <p:dataTable> ignores any children that are not columns. Whilst there are ways using composite components to indicate with interface properties the precise Class type that the component appears to be, fooling <p:dataTable> by making it look like a column does not work \u2013 I tried this and it failed, and there are posts on the Primefaces forum citing the same issue.<\/p>\n The simple solution was to use <c:if> to conditionally include columns. This eventually worked correctly, once I had fixed a particularly nasty incorrect JSTL namespace issue which is fully described in this post here<\/strong><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" This can be done e.g. by a Facelets Decorator using <ui:insert> and I have used this in a number of places. However, in one case, I wanted to make a complex treeBrowser custom tag switchable between editable mode and readonly using just a single flag passed as an attribute. Note that I did not want […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[22],"tags":[40,184,112,16],"_links":{"self":[{"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/1392"}],"collection":[{"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1392"}],"version-history":[{"count":0,"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/1392\/revisions"}],"wp:attachment":[{"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1392"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1392"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/salientsoft.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1392"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}