deepdash

deepdash

tree traversal for lodash

Installation

In a browser load script after lodash:

<script src="lodash.js"></script>
<script src="deepdash.js"></script>

Using npm:

npm i --save deepdash

In Node.js:

//mixin new method into lodash object
const _ = require('deepdash')(require('lodash'));

Usage

let obj = {
  a: {
    b: {
      c: {
        d: [
          { i: 0 },
          { i: 1 },
          { i: 2 },
          { i: 3 },
          { i: 4 },
          { i: 5 },
          {
            o: {
              d: new Date(),
              f: function() {},
              skip: {
                please: {
                  dont: {
                    go: {
                      here: 'skip it',
                    },
                  },
                },
              },
            },
          },
        ],
        s: 'hello',
      },
      b: true,
    },
    n: 12345,
    u: undefined,
  },
  nl: null,
};
_.eachDeep(obj, (value, key, path, depth, parent, parentKey, parentPath) => {
  console.log(
    _.repeat('  ', depth) +
      key +
      ':' +
      (value === null ? 'null' : typeof value),
    parentPath && ' @' + parentPath
  );
  if(key=="skip"){
    return false;//return false explicitly to skip iteration over current value's children
  }
});

Console:

a:object
  b:object  @a
    c:object  @a.b
      d:object  @a.b.c
        0:object  @a.b.c.d
          i:number  @a.b.c.d[0]
        1:object  @a.b.c.d
          i:number  @a.b.c.d[1]
        2:object  @a.b.c.d
          i:number  @a.b.c.d[2]
        3:object  @a.b.c.d
          i:number  @a.b.c.d[3]
        4:object  @a.b.c.d
          i:number  @a.b.c.d[4]
        5:object  @a.b.c.d
          i:number  @a.b.c.d[5]
        6:object  @a.b.c.d
          o:object  @a.b.c.d[6]
            d:object  @a.b.c.d[6].o
            f:function  @a.b.c.d[6].o
            skip:object  @a.b.c.d[6].o
      s:string  @a.b.c
    b:boolean  @a.b
  n:number  @a
  u:undefined  @a
nl:null

Chaining works too:

  _(obj).eachDeep((value, key, path, depth, parent, parentKey, parentPath) => {/* do */}).value();

Methods

eachDeep (forEachDeep)

_.eachDeep(object, [iteratee=_.identity]) Invokes given callback for each field and element of given object or array, nested too.

Arguments:

• object: (Object) The object to iterate over.
• [iteratee]: (Function) The function (_.identity by default) invoked per iteration. iteratee will be called with:
  • value, key, path, depth, parent, parentKey, parentPath, [parents]
• • [track]: (Boolean) option (false by default) to track parents from current back to the root, useful for circular reference detecting. If true, iteratee will have additional parents object argument with values, keys and paths arrays inside.

Example:

  let circular = { a: { b: { c: {} } } };
  circular.a.b.c = circular;
  _.eachDeep(
    circular,
    (value, key, path, depth, parent, parentKey, parentPath, parents) => {
      if (_.indexOf(parents.values, value) !== -1) {
        console.log(
          "Circular reference skipped for '" + key + "' at " + parentPath
        );
        return false;
      }
      //do your things
    }
  ,{track:true});

Console:

  Circular reference skipped for 'c' at a.b

Other traversal methods

Feel free to request other methods implementation.