[news.eclipse.tools.jdt] Re: How to remove parameter using ASTParser

[Mike Yawn <myawn@xxxxxxxx>]

Fayezin Islam wrote:
> Hello,
>
> Suppose, I have a method invocation like -
> class1.method1(par1, par2, par3);
>
> I want to change it to:
> class1.method1(par2);
>
> How can I do this using the Eclipse ASTParser?
>
> The parameters to be removed are decided by Static Analysis (Program 
> Slicing).
>
> Please note that I should be able to change invocations like these ase 
> well -
>
> class1.method1(new Object(), par2, par3);
>
> Previously, I have analyzed code using the ASTParser but did not 
> transformed/change code as of yet.
>
> Therefore, a reply with an example will be very appreciated...
>
> Thanks,
>
> Fayezin
I don't have an example that does exactly what you're looking for, but 
the basic steps would be:

- Create a visitor class (extends ASTVisitor); call it something 
meaningful (like ArgumentRemovalVisitor), as if you work with the AST a 
lot you'll probably end up creating lots of these.
- Implement a method to visit MethodInvocations:
	public boolean visit(MethodInvocation node) { ... }
- Within the visit method:
	- check node.getName().getIdentifier() to find the methods you want to 
alter
	- node.arguments() will then be the live list of argument nodes, from 
which you can delete any arguments that aren't wanted.

- to invoke your visitor, do something like:
	ArgumentRemovalVisitor arv = new ArgumentRemovalVisitor();
	myCompilationUnit.accept(arv);

The compilation unit in this case is a CompilationUnit, as returned by 
ASTParser.createAST(), not an ICompilationUnit.