If you want to avoid the use of ExpandoMetaClass and that you
potentially want to have this behavior on multiple classes, you can now
rely on the traits for this. I had written this in a presentation about
traits for S2GX last year:
|trait ExpandoTrait {||
|| private final Map<String,?> values = [:]||
|| def propertyMissing(String name) { values.get(name) }||
|| void setProperty(String name, value) {||
|| println "Setting dynamic property $name"||
|| values.put(name, value)||
|| }||
||}||
||class Person implements ExpandoTrait {||
|| String name||
||}||
||def p = new Person(name: 'Cedric')||
||assert p.name == 'Cedric'||
||p.age = 35||
||assert p.age == 35|
Best regards,
\On 05/26/2015 11:02 PM, Schalk Cronjé wrote:
I did at one stage, and the result is the same. The only way I could
get it to work is something like
class A {
private Expando props = new Expando()
void addSomeProp( String name, String key, def value) {
def p = props.getProperty(name)
if (null = p) {
props.setProperty( name,[:] )
}
props."${name}"[key]=value.toString()
}
def missingProperty( String name ) {
def p = props.getProperty(name)
if( null = p ) {
throw new MissingPropertyException( name,this.class )
}
return p
}
}
Which is strange, as it is what I think ExpandoMetaClass would do anyway.
On 26/05/2015 19:33, KARR, DAVID wrote:
-----Original Message-----
From: Schalk Cronjé [mailto:[email protected]]
Sent: Tuesday, May 26, 2015 8:21 AM
To: [email protected]
Subject: Dynamic adding properties to class
This should be straight-forward, but it is failing for me (at least
on
2.3x and 2.4.x). What am I doing wrong?
Here is some code sufficiently distilled.
class A {
void addSomeProp( String name,String key, def value ) {
if(metaClass.getMetaProperty(name)==null) {
metaClass."${name}" = [:]
}
metaClass."${name}"[key]=value.toString()
}
}
Perhaps try "metaClass.hasProperty(name)" instead?
A a = new A()
a.addSomeProp( 'info','version',3) // Fails with: No such
property:
info for class: groovy.lang.MetaClassImpl
The idea is to add a map (of name) if it does not exist, and then
add
items into the map.
--
Schalk W. Cronjé
Twitter / Ello / Toeter : @ysb33r
--
Cédric Champeau
Groovy language developer
http://twitter.com/CedricChampeau
http://melix.github.io/blog
