Create dynamically closures in Groovy from a String object

Question

i would like to create a query with the Criteria API in Grails (GORM). The query will have to be something like this:

MyEntity.createCriteria().list{
   asso         


        

Answer 1

What about createAlias?. You could try something like this:

def path = "assoc.parent.code"

def split = path.split(/\./)

MyEntity.createCriteria().list {
  // this will get you 'createAlias( assoc.parent, alias1 )'
  createAlias split.take( split.size() - 1 ), "alias1"

  // this will get you 'eq(alias1.code, userInput)'
  eq "alias1.${split[-1]}", userInput
}

This snippet is not generic, but you get the idea.

---

Update

Not conventional, but you can build a string containing the code with the closures and evaluate it using GroovyShell:

assoc = 'assoc.parent.child.name'
split = assoc.split( /\./ )
path  = split[-2..0] // will get us 'child.parent.assoc';
                     // we will build it from inside-out

def firstClosure = "{ eq '${split[-1]}', 'john doe' }"
def lastClosure = firstClosure

for (entity in path) {
  def criteriaClosure =  "{ ${entity} ${lastClosure} }"
  lastClosure = criteriaClosure
}

assert lastClosure == "{ assoc { parent { child { eq 'name', 'john doe' } } } }"
def builtClosure = new GroovyShell().evaluate("return " + lastClosure)
assert builtClosure instanceof Closure