CODEWITHSUNDEEP
javascriptjson
Zeno
Zeno

Reputation: 1829

Retrieve JSON object?

I have JSON/JS like this that populates data:

  var settingDefs = [];
  settingDefs.push({
    name:'responses', label:'Responses', type:'aeditor', 
    defaultValue: Object.toJSON([
      {"id":"1", "name":"Bob", "text":"Is here"},
      {"id":"2", "name":"James", "text":"Online"},
    ])
  });

How would I retrieve an entry say if I had "1" and I wanted to lookup using that "1" to retrieve the name/text for that entry (entry 1)?

Upvotes: 0

Views: 116

Answers (3)

Roman Bataev
Roman Bataev

Reputation: 9361

Not sure why you need Object.toJSON here. I would do something like this:

 var settingDefs = [];
  settingDefs.push({
    name:'responses', label:'Responses', type:'aeditor', 
    defaultValue: [
      {"id":"1", "name":"Bob", "text":"Is here"},
      {"id":"2", "name":"James", "text":"Online"},
    ]
  });

var valueWithId1 = $.grep(settingDefs[0].defaultValue, function(el){return el.id === "1";})[0]

I use jQuery.grep here. If you don't use jQuery or other libraries with similar function you will need to iterate through the array manually, as others have suggested

Upvotes: 0

Hamish
Hamish

Reputation: 23316

It's unclear from your question what that entry refers to.

If the JSON de-serialized object looks like this:

var foo = [
  {"id":"1", "name":"Bob", "text":"Is here"},
  {"id":"2", "name":"James", "text":"Online"},
]

Then you have an array of objects where each object has a property id with a string value (that happens to be a number).

Therefore, you need to iterate over the array and test the value of the id property:

var findObjById = function(arr, idToFind) {
    for(i = 0; i < arr.length; i++) {
        if(arr[i].id === idToFind) return arr[i];
    }
}
var obj = findObjById(foo, "1");

Upvotes: 1

maerics
maerics

Reputation: 156374

Assuming that each defaultValue property will be an Array and not a JSON string - you should iterate through the settingDefs array and return all (or maybe just the first?) entry in the defaultValue property whose id matches the one you have. Something like this:

function lookupValueById(sds, id) {
  for (var i=0; i<sds.length; i++) {
    for (var j=0; j<sds[i].defaultValue.length; j++) {
      var el = sds[i].defaultValue[j];
      if (el.id == id) return el;
    }
  }
  return null;
}
lookupValueById(settingDefs, 1); // => {id:'1', name:'Bob', text:'Is Here'}

Upvotes: 1

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