PokeAPI + Angular: How to get pokemon's evolution chain

Issue

I am an Angular novice and am learning a little by trying to pull the evolution chain for each pokemon using pokeapi but having a difficult time because of deep nesting.

A typical response object is returned like this:

{
  "baby_trigger_item": null,
  "id": 2,
  "chain": {
    "evolution_details": [],
    "evolves_to": [
      {
        "evolution_details": [
          {
            "min_level": 16,
            "min_beauty": null,
            "time_of_day": "",
            "gender": null,
            "relative_physical_stats": null,
            "needs_overworld_rain": false,
            "turn_upside_down": false,
            "item": null,
            "trigger": {
              "url": "http://pokeapi.co/api/v2/evolution-trigger/1/",
              "name": "level-up"
            },
            "known_move_type": null,
            "min_affection": null,
            "party_type": null,
            "trade_species": null,
            "party_species": null,
            "min_happiness": null,
            "held_item": null,
            "known_move": null,
            "location": null
          }
        ],
        "evolves_to": [
          {
            "evolution_details": [
              {
                "min_level": 36,
                "min_beauty": null,
                "time_of_day": "",
                "gender": null,
                "relative_physical_stats": null,
                "needs_overworld_rain": false,
                "turn_upside_down": false,
                "item": null,
                "trigger": {
                  "url": "http://pokeapi.co/api/v2/evolution-trigger/1/",
                  "name": "level-up"
                },
                "known_move_type": null,
                "min_affection": null,
                "party_type": null,
                "trade_species": null,
                "party_species": null,
                "min_happiness": null,
                "held_item": null,
                "known_move": null,
                "location": null
              }
            ],
            "evolves_to": [],
            "is_baby": false,
            "species": {
              "url": "http://pokeapi.co/api/v2/pokemon-species/6/",
              "name": "charizard"
            }
          }
        ],
        "is_baby": false,
        "species": {
          "url": "http://pokeapi.co/api/v2/pokemon-species/5/",
          "name": "charmeleon"
        }
      }
    ],
    "is_baby": false,
    "species": {
      "url": "http://pokeapi.co/api/v2/pokemon-species/4/",
      "name": "charmander"
    }
  }
}

I have to get to evolves_to property, and grab species.name as well as evolution_details.min_level and evolution_details.trigger.name, and evolution_details.item if not null

But as you can see, the evolves_to property, itself contains another evolves_to nested inside, which has another nested inside

This is my sad attempt (after http.get) and I'm just stuck now.

var evoObject = response.data;

function loopEvo(obj){
    angular.forEach(obj, function(value, key, object){
        if (key == 'evolves_to' && value != []) {
            //from here I can get top level data, but...
        }
    });
}

loopEvo(evoObject.chain);

I don't know how to recursively dive into objects and continually grab data, can anyone provide any help? I would love to use this as a great learning opportunity in traversing complex json objects.

Solution

You could always just avoid using Angular and stick with plain JS to build out your evolution chain... try giving this a go, it was based on your angular for loop. This should leave you with an array (evoChain) of the objects containing the data you are looking for ordered from first evolution at 0 index to last evolution at the last index.

var evoChain = [];
var evoData = response.data.chain;

do {
  var evoDetails = evoData['evolution_details'][0];

  evoChain.push({
    "species_name": evoData.species.name,
    "min_level": !evoDetails ? 1 : evoDetails.min_level,
    "trigger_name": !evoDetails ? null : evoDetails.trigger.name,
    "item": !evoDetails ? null : evoDetails.item
  });

  evoData = evoData['evolves_to'][0];
} while (!!evoData && evoData.hasOwnProperty('evolves_to'));

In your sample case above the resulting array should appear as follows:

[{
    "species_name": "charmander",
    "min_level": 1,
    "trigger_name": null,
    "item": null
}, {
    "species_name": "charmeleon",
    "min_level": 16,
    "trigger_name": "level-up",
    "item": null
}, {
    "species_name": "charizard",
    "min_level": 36,
    "trigger_name": "level-up",
    "item": null
}]

Answered By - Ryan