JCodeModel and elseif

Question

I'm generating Java source code with JCodeModel and want to get an "if-elseif" block like this:

 if (foo){

 } else if (bar) {

 }

As far as I understand the according code would be something like this (where m is a JMethod):

JConditional cond = m.body()._if(JExpr.direct("foo"));
cond._elseif(JExpr.direct("bar"));

Seems to be straight forward, but the result is this:

if (foo) {
    } else {
        if (bar) {
        }
    }

You see the syntactic difference, it's not actually an "elseif". Semantically it's the same, I know, but I need it to be generated as shown before (it's part of educational software). Any way to do this?

score 1 · Accepted Answer · answered Jan 14 '13 at 09:10

Unfortunately you can not do this using JConditional because of its implementation. Have a look at the source of the method _elseif:

 public JConditional _elseif(JExpression boolExp) {
     return _else()._if(boolExp);
 }

As you can see, this method just invoke _else() and then _if internally.

Actually _else() is JBlock which contains braces ({ ... }) by default. This property of JBlock can not be switched off manually because it doesn't contain such setter. braces could be switched off only through special constructor of JBlock:

 public JBlock(boolean bracesRequired, boolean indentRequired) {
     this.bracesRequired = bracesRequired;
     this.indentRequired = indentRequired;
 }

but you are not able to set you own object to _else field of JConditional object outwardly.

The only way is copy JConditional class implementation and generate your own, which will allow you such code manipulation.

UPD: Of course you can always use Reflection as workaround for manually switching flag bracesRequired of _else object to false.

JCodeModel and elseif

1 Answers1