CODEWITHSUNDEEP
groovyclosures
xain
xain

Reputation: 13839

Load closure code from string in Groovy

is it possible to load a closure's code from a string (that may come from a file) in Groovy ?

Upvotes: 12

Views: 7675

Answers (3)

Binil Thomas
Binil Thomas

Reputation: 13779

Did you mean something like this?

groovy:000> sh = new GroovyShell()
===> groovy.lang.GroovyShell@1d6dba0a
groovy:000> closure = sh.evaluate("{it -> println it}")
===> Script1$_run_closure1@59c958af
groovy:000> closure(1)
1
===> null
groovy:000> [1,2,3,4].each { closure(it) }
1
2
3
4
===> [1, 2, 3, 4]
groovy:000>

Upvotes: 16

paradoxbomb
paradoxbomb

Reputation: 414

This should work, not sure if it's the most elegant solution:

ClassLoader parent = getClass().getClassLoader()
GroovyClassLoader loader = new GroovyClassLoader(parent)
Class groovyClass = loader.parseClass("class ClosureHolder {def closures = [{ println 'hello world!' }]}")
def allTheClosures = groovyClass.newInstance()

allTheClosures.closures.each {
    it()
}

Just put your closures inside the list when reading them in.

Upvotes: 1

virtualeyes
virtualeyes

Reputation: 11237

If you mean something like:

def cl = "{'hello'}" as Closure // fails, can't convert string to closure

No.

However, it appears evaluate() may be an option in this case: http://groovy.329449.n5.nabble.com/creating-closure-from-string-instance-td343089.html

Upvotes: -1

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