JSF datatable with paging and sorting and browser-back - jsf-2

Question

We are using Primefaces datatable component with sorting, pagination and a LazyDataModel in order to display search results. The backing bean of the search page is ViewScoped.
From the search result list a user can select a result item in order to view the details. This is implemented as a new page request, e.g. <h:link value="Show Details" outcome="showDetails?id=11234"/>. By clicking the browser back button the user will navigate back to the search result list.
The problem is that the datatable will be in initial state again, so it wont display the last selected sort order and page. This is the case in most browsers, only Firefox 11 seems to keep those DOM changes in cache. Neither IE nor Chrome.
Does anybody has a good approach how to handle this? We actually don't need "ajaxified" sorting and paging. We would prefer handling everything through ViewParams, but this seems not to be supported by primefaces.

Answer 1

I ran into this as well, and I developed a coding pattern that might help. It isn't really a PrimeFaces thing (which I am using as well) -- more of a technique for using book-markable links with JSF 2.
In the markup, I include all the parameters for the page as follows:
<f:metadata>
<f:viewParam name="orderID" value="#{bean.orderID}" />
<f:viewParam name="sortMode" value="#{bean.sortMode}" />
<f:viewParam name="firstRecord" value="#{bean.firstRecord}" />
<f:viewParam name="pageSize" value="#{bean.pageSize}" />
</f:metadata>
Each of those values is backed in the backing bean such that, if they are not set, they produce a suitable default value. For example:
public int getPageSize() {
if (pageSize < MIN_PAGE_SIZE) pageSize = DEF_PAGE_SIZE;
if (pageSize > MAX_PAGE_SIZE) pageSize = DEF_PAGE_SIZE;
return pageSize;
}
A link to this view can be generated as follows:
Now you implement user controls to change those values, and regenerate the table each time they are changed. You should still use AJAX for that -- for example:
<p:spinner value=#{bean.pageSize} >
<p:ajax update="tableID" />
</p:spinner>
In the setter methods, you have to trigger the re-generation of the table, but that's the gist of it. I hope this helps.
UPDATE:
To handle pagination, you simply need to add links for first page, prior page, next page, etc. The links will look something like this:
<h:link value="First Page" outcome="thisPage">
<f:param name="orderID" value="#{bean.orderID}" />
<f:param name="sortMode" value="#{bean.sortMode}" />
<f:param name="firstRecord" value="0" />
<f:param name="pageSize" value="#{bean.pageSize}" />
</h:link>
<h:link value="Next Page" outcome="thisPage">
<f:param name="orderID" value="#{bean.orderID}" />
<f:param name="sortMode" value="#{bean.sortMode}" />
<f:param name="firstRecord" value="#{bean.nextRecord}" />
<f:param name="pageSize" value="#{bean.pageSize}" />
</h:link>
etc. You need to implement properties in the backing bean to calculate what the firstRecord param ought to be.