The extensions.groovy bundle includes a Groovy Builder which makes it easy to create JSON documents from Sling scripts. This code is inspired by the builder contained in Andres Almiray's json-lib project (http://json-lib.sourceforge.net/). However, Sling's builder is not compatible with the json-lib builder.
An instance of this class is available to all Groovy scripts as a variable named jsonBuilder.
A basic script looks like this:
out.write jsonBuilder.json {
text currentNode.getProperty("text").string
} as String
Examples
These examples are taken from the test case: http://svn.apache.org/viewvc/sling/trunk/bundles/commons/json/src/test/groovy/org/apache/sling/commons/json/groovy/JSONGroovyBuilderTest.groovy?view=markup.
The JSON output below is formatted for readability. Actual output will be compact.
jsonBuilder.json { }
produces...
{}
jsonBuilder.json([])
produces...
[]
jsonBuilder.json {
string "json"
integer 1
bool true
}
produces...
{
'string' : 'json',
'integer' : 1,
'bool' : true
}
jsonBuilder.json {
first { integer 42 }
second { integer 48 }
}
produces...
{
'first' : {
'integer' : 42
},
'second' : {
'integer' : 48
}
}
jsonBuilder.json {
books {
book {
title "The Definitive Guide to Grails"
author "Graeme Rocher"
}
book {
title "Groovy in Action"
author "Dierk Konig"
}
}
}
produces...
{
'books' : {
'book' : [
{ 'title' : 'The Definitive Guide to Grails', 'author' : 'Graeme Rocher' },
{ 'title' : 'Groovy in Action', 'author' : 'Dierk Konig' }
]
}
}
Creating a Wrapper
The json pseudo-method of JSONGroovyBuilder produces an instance of org.apache.sling.commons.json.JSONObject based on the parameters passed to it. If a different psuedo-method is called, the method name will be used to create a wrapper object. For example:
builder.books {
book {
title "The Definitive Guide to Grails"
author "Graeme Rocher"
}
book {
title "Groovy in Action"
author "Dierk Konig"
}
}
produces...
{
'books' : {
'book' : [
{ 'title' : 'The Definitive Guide to Grails', 'author' : 'Graeme Rocher' },
{ 'title' : 'Groovy in Action', 'author' : 'Dierk Konig' }
]
}
}