Groovy/Grails JSON converting of complex objects and collections

Question

I have following mapping representing categories tree:

class Category {

  String name
  static belongsTo = [parent: Category]
  static hasMany = [categories: Category]

}

The thing I want to do is to render all of the category tree and exclude field parent from rendering.

render category as JSON

renders only first level of hierarchy and doesn't render the names of child categories. I.e. having following tree:

Root->cat2->cat4 cat3

I have

{"class":"project.Category",
 "id":1,
 "categories":[{"class":"Category","id":2},
               {"class":"Category","id":3}],
 "name":"Root",
 "parent":null}

I don't want "class" and "parent" attributes and want to see cat4 data in this tree.

Is there some special lib or plugin or maybe it is possible to config standard JSON converter or domain class?

Oleksandr · Accepted Answer · 2010-07-08 13:30:23Z

2

You can try to build custom JSON via JSONBuilder:

render(builder:'json') {
  id(category.id)
name(category.name)
  categories {
    category.categories?.each {
      categories (
        id: it.id,
        name: it.name
      )
    }
  }
}

answered Jul 8, 2010 at 13:30

Oleksandr

3,8018 gold badges53 silver badges80 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Dónal · Accepted Answer · 2010-07-08 11:59:13Z

0

JSON-lib is a library that offers tight control over the format of Java/Groovy objects serialized to JSON. From the docs:

Since version 2.0 Json-lib has integrated Groovy support, meaning that POGOs can be transformed into JSON and back, in the same manner as you do now with POJOs.

answered Jul 8, 2010 at 11:59

Dónal

188k177 gold badges590 silver badges851 bronze badges

2 Comments

Vladimir Over a year ago

The question is actually: HOW to configure this lib?

Dónal Over a year ago

Put it on your classpath either by adding the JAR to the /lib directory of your Grails app, or specifying it as a dependency in BuildConfig.groovy

tim_yates · Accepted Answer · 2010-07-08 12:02:22Z

0

I think you'd have to do it yourself :-/

something like:

def categoryToMap( cat ) {
  def a = [ id:cat.id, name:cat.name ]
  if( cat.categories ) a << [ categories:cat.categories.collect { categoryToMap( it ) } ]
  a
}

then something like:

render categoryToMap( category ) as JSON

edited Jul 8, 2010 at 12:02

answered Jul 8, 2010 at 11:55

tim_yates

172k29 gold badges359 silver badges354 bronze badges

1 Comment

Vladimir Over a year ago

That will do but categories tree above is only simple exmapmle. But I am seek for more universal and if it possible standard way.

Collectives™ on Stack Overflow

Groovy/Grails JSON converting of complex objects and collections

3 Answers 3

Comments

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related