Question

I want to define a tag separator tag, which inside a list tag, can add separator between items.

The sample code is:

List<String> users = new ArrayList<String>();
users.add("Jeff");
users.add("Mike");

#{list users, as: 'user'}
    #{separator ' + ' /}
    <span>${user}</span>
#{/list}

If I don’t use the separator tag, the code will be:

#{list users, as: 'user'}
    ${user_isFirst ? '' : ' + '}
    <span>${user}</span>
#{/list}

The generated html code will be:

<span>Jeff</span> + <span>Mike</span>

I tried defined a fastTag:

public static void _separator(Map<?, ?> args, Closure body, PrintWriter out, GroovyTemplate.ExecutableTemplate template, int fromLine) {
    Object value = args.get("arg");

    // TODO how to get the value of `as` defined in parent `list` tag?

    out.print(value);
}

But the problem is I can’t get the value of as defined in list tag (which is user) in this case.

Answer 1

You can create a custom list tag in groovy like this

#{list items:_arg, as:'tmp'}

    %{
            attrs = [:]
            attrs.put(_as, tmp)
    }%

    #{ifnot tmp_isFirst}${_sep}#{/ifnot}
    #{doBody vars:attrs /}

#{/list}

and use it like this

#{myList users, as:'user', sep:','}
    ${user}
#{/myList}