xformResponse.js

// xformResponse.js
// ------------------------------------------------------------------
//
// pre-transform the response before the XML-to-JSON step.
//
// created: Wed Jan  7 08:06:03 2015
// last saved: <2015-January-07 10:41:38>

// expected input:
//
// {
// "school":{
//   "teachers" : [
//     {"students" :[{"name": "student1"}, {"name": "student2"}], "name" : "teacher1"},
//     {"students" :[{"name": "student3"}, {"name": "student4"}], "name" : "teacher2"}
//   ]
// }
// }
//
// desired output:
//
// {
//   school:{
//     teachers : {
//       teacher : [
//         {students : { name: [student1,student2} }, name : teacher1},
//         {students : { name: [student3,student4} }, name : teacher2}
//       ]
//     }
//   }
// }
//
// Running the output through the JSON-to-XML step will produce the
// desired XML output, which looks like:
//
// <school>
//   <teacher>
//     <name>teacher1</name>
//     <students>
//       <name>student1</name>
//       <name>student2</name>
//     </students>
//   </teacher>
//   <teacher>
//     <name>teacher1</name>
//     <students>
//       <name>student1</name>
//       <name>student2</name>
//     </students>
//   </teacher>
// </school>


function parseContent(content) {
  var ctype = context.getVariable('response.header.content-type') + '';
  if (ctype.indexOf('application/json') === 0) { // starts with
    content = JSON.parse(content);
  }
  return content;
}

function fixupArray(obj, propName, accessor) {
  var type = Object.prototype.toString.call(obj), i,
      a = [], rval = {};
  if (null !== obj) {
    if (type === "[object Array]") {
      for (i=0; i<obj.length; i++) {
        a.push(accessor(obj[i])); // string
      }
      rval[propName] = a;
    }
  }
  return rval;
}

function fixupStudents(obj) {
  return fixupArray(obj, 'name', function(o){return o.name;});
}
function fixupTeachers(obj) {
  return fixupArray(obj, 'teacher', function(o){return o;});
}


// ********************************************
// Execution starts here

var c = context.getVariable('response.content') + '',
    body = parseContent(c);

if (body.school) {
  if (body.school.teachers) {
    body.school.teachers.forEach(function(item){
      if (item.students) {
        item.students = fixupStudents(item.students);
      }
    });
    // un-comment the following line to get a parent item
    // around all the teacher items. 
    //body.school.teachers = fixupTeachers(body.school.teachers);
  }
}

context.setVariable('response.content', JSON.stringify(body, null, 2));