Extreme Java When vanilla Java is not enough

18Sep/090

Copying html attributes on Lift bindings

Since Java and Scala are complementary, I will post Scala-related stuff here, too (without creating a new blog).

Today's tip refers to Lift (Scala's JavaEE/Rails/Grails/Django). Suppose your webdesigner gives you this XHTML:

<input type="text" class="x" style="width: 100px;"/>

When you bind this using Lift, one of possible solutions is surround it with a tag:

<mybind:myfield><input type="text" class="x" style="width: 100px;"/></mybind:myfield>

Please notice I put it without spaces or newlines between "mybind:myfield" and "input" - this will be important later.

I prefer this way because this XHTML can be opened in other applications, like Firefox and Dreamweaver, making life easier for the webdesigner.

Then, if I bind it using old mama's recipe:

bind("mybind", form, "myfield" -> myfield.toForm)

Lift will remove my "input" tag and replace it - destroying "class" and "style". To solve this, I merge "toForm" tag with original attributes:

def merge(form : => Box[NodeSeq])(input : NodeSeq) : NodeSeq = {
  var in = input.first
  var attrs = form.open_!.first.attributes
 
  new Elem(in.prefix, in.label,
      in.attributes append attrs,
      in.scope, Group(in.child))
}
bind("mybind", form,
    FuncBindParam("myfield", merge(myfield.toForm)))

Function "merge" takes the form and returns a function that receives the original XHTML and translates it into XHTML with Lift's attributes ("id", "name", "lift:gc", etc). I guess I can improve it somehow, but works great. And, since I'm keeping only the first child of source XHTML, you need to keep "bind" and "input" together (as I said before).

I know I can use a map function to ignore whitespaces, but I'll leave it as an later exercise (for you and for me, too).

14Feb/084

Long lines in Java Tooltips (or multiline tooltips)

Do you want to show a tooltip with more than one line? Are your tooltips too large to fit in one line? The solution is easier than you think. Tooltips, in Java, accept HTML code:

jcomponent.setToolTipText("HTML tooltip");

It isn't a Firefox, but is very powerful. And, when I said HTML, I also think about CSS. So, you can set your tooltips using this evil cheat:

<html><body>
<strong><div style="width: 300px; text-justification: justify;"></strong>
Blah Blah Blah (repeat "blah" 100 times)
</div>
</html></body>

Have you seen automatic line breaks and the justification? Oh, yeah!

BTW, do you remember old days, when you couldn't believe WordPad didn't have justified text? :)