Skip to main content

Using a non-managed bean with an XPage

For a long time, every time I wanted to create a controller or model bean, I wrote it and then added it to my managed beans in faces-config. But this can create a very bloated faces config, particularly when these beans are only used by a single XPage. Then I learned about dataContext.

A dataContext can be created for any container all the way up to the xp:view element, which allows for great flexibility. It works like this:

<xp:this.dataContexts>
  <xp:dataContext var="beanVar">
    <xp:this.value><![CDATA[${javascript:
      var unid = param.get("unid");
      var notice:package.Notice = new package.Notice(unid);
      return notice;}]]></xp:this.value>
  </xp:dataContext>
</xp:this.dataContexts>

This bean can then be bound to controls like so:
<xp:text id="name" value="#{beanVar.name}"></xp:text>

If the bean returns a collection, this can be used as a data source for a repeat control like so:
<xp:repeat id="repeatItems" value="#{beanVar.itemList}" var="item" rows="50">
  <div class="row>
    <xp:text id="itemName" value="#{item.name}">
    <xp:text id="itemQty" value="#{item.quantity}">
  </div>
</xp:repeat>

So it works just like a managed bean except it is declared in the XPage instead of faces-config. This has the added benefit of making it clearer where the bean variable name is coming from when you are looking at the XPage in the future.

Comments

Popular posts from this blog

XPages Application Framework (Part 1?)

Note: I changed projects and priorities after my last POI article, resulting in a long hiatus. I anticipate using that framework on my current project and will likely refine and complete my related article series. For the past several months, I've been fortunate enough to lead a project overhaul from traditional Domino Webapp to XPages. I had a few goals in mind, but the top three were integrating Bootstrap, embracing MVC principles, and eliminating all SSJS . I imagine the motivation for Bootstrap integration is self-explanatory. There is an OpenNTF project out there called Bootstrap4XPages. I didn't use that for a number of reasons - the main being a policy in the current environment. But you may ask yourself (if you didn't follow that link), why so much hatred for SSJS? I have a litany of reasons. It impacts readability of the XPage source; it hurts maintainability when logic is scattered across dozens of XPages, custom controls, and script libraries; it mixes log...

Rows per page selection: Part 1

I was asked to create a control that would allow users to select the number of rows per page in a view/repeat control (the application uses both). It seemed simple at first, but I ran into a few issues that I thought I'd share the solutions to. First, lets start at the beginning. I went through the relevant design elements and set row="#{viewScope.tableRows}" , and I created an xp:comboBox with value="#{viewScope.tableRows}" and added items for 20, 30, 50, and 100, and I assigned it an onChange event handler that did a partial execution and partial refresh of a div containing the combo box, pager and the table. Then I started fixing all the problems. Problem 1: The combobox value was a string, but the rows parameter requires an integer. This was causing IllegalArgumentException / java.lang.String incompatible with java.lang.Integer. I added a NumberConverter, but this only slightly changed the exception message to java.lang.Long incompatible with java.lang....

Project in Review - Part 3: What didn't work

Of course, not everything was an unmitigated success. I tried many things that didn't work out. Much of which I've removed and forgotten about, but a few things remain - either scarred into my psyche or woven too deeply to fix. What didn't work Storing my entire configuration in application.properties Using properties files is great. It let me get configuration out of a profile document and into something much easier to edit - particularly configuration that users will never see or maintain (and thus there is no need for an interface for). But I took it too far. The paths to the other databases are there, and that's good. But view aliases are also there, and that was a mistake. I already have a ViewDefinition enum that describes each view and all the information I need to know about it. I could have set view names there, but instead I'm reading them from the application config. I can change where a view is pointing without having to go into my code. Except of co...