Question

Having two nested tags, How is it possible to inject a variable into inner tag binding?

class CriteriaTagLib {

    def criteria = { attrs, body ->
        out << "start"
        out << body.call()
        out << "end"
    }

    def eq = {
        out << "eq${group}"
    }
}

And having in a GSP page :

<g:criteria>
    <g:eq></g:eq>
<g:criteria>

The question is how to set a value for group (used inside of eq) from inside of criteria.

Answer 1

<q:criteria> can put own context/data as a request scope attribute (or page scope), and use it inside by <q:eq> (don’t forget to remove it on closing tag). Like:

static final CONTEXT = this.class.name

def criteria = { attrs, body ->
    def data = [
        group: 'test 1'
    ]
    request.setAttribute(CONTEXT, data)
    out << "start"
    out << body.call()
    out << "end"
    request.removeAttribute(CONTEXT)
}


def child = { attrs, body ->
   def data = request.getAttribute(CONTEXT)
   out << 'eq'
   out << data.group  
}