• Wparts
• WpartChoose

wpart_choose

wpart_choose provides if functionality in views.

During the tag expanding, wpart lookups for wpart:whens inside its body (and one optional wpart:otherwise. First wpart:when body which test evaluates to true is inserted as a wpart:choose value. Otherwise, wpart:otherwise is inserted.

Because XHTML standard does not allow to use < character in attribute value, we can use some substitutions of comparison operators:

• eq -> =:=

• neq -> =/=

• lt -> <

• le -> =<

• gt -> >

• ge -> >=

Attributes

test

Erlang code, which will be evaluated and the result will be compared to true.

Tags

wpart:when

One of the if 's branch - the wpart:when 's test attributes are evaluated sequentially. If its test has been evaluated to true as first, its body is inserted as a wpart:choose value.

wpart:otherwise

In case of all whens failure, its body is inserted as a return of wpart:choose expanding.

Example

  ...
  <wpart:choose>
      <wpart:when test="1 + 1 eq 3">
          Impossible!
      </wpart:when>
      <wpart:when test="random:uniform(2) eq 2">
          Sometimes...
       </wpart:when>
       <wpart:otherwise>
           Last resort!
       </wpart:otherwise>
   </wpart:choose>
   ...