Deep population support

[ivan-rangel]

Hi there great tool you've created.

I'm having issues with deep population.

It seems the current version only support first-level population and ignore the rest of the fields.

Query Params:

?populate=_lastRequests._sender.username

Current Results:

"_lastRequests": [
                {
                    "_id": "5ba11cf4bc60615625594146",
                    "_sender": "5b8ee934aaad4e4de8fffc96"
                }
   ],

Expected Result:

"_lastRequests": [
                {
                    "_id": "5ba11cf4bc60615625594146",
                    "_sender": {
                         "_id":"5b8ee934aaad4e4de8fffc96",
                         "username":"ANY"
                }
   ],

Hope yo have a chance to take a look at this. Thanks!!

[leodinas-hao]

Hi @ivan-rangel thanks for opening the issue & sorry for the late response. If this feature is still a must-have for you. You're more than welcome to submit a PR for it.

[leodinas-hao]

Issue closed

[robcaa]

@leodinas-hao I rewrote the castPopulate method to allow deep population and multiple select fields. Here is the code:

const castPopulate = function(val) {
  return val.split(",").map(function(qry) {
    var array = qry.split(".");
    const insertPopulate = (index = 0) => {
      if (array[index + 1]) {
        return {
          path: array[index],
          populate: insertPopulate(index + 1),
        };
      } else {
        const i = array[index].indexOf(":");
        if (i > -1) {
          const elements = array[index].split(":");
          return { path: elements.shift(), select: elements.join(" ") };
        } else {
          return { path: array[index] };
        }
      }
    };

    return insertPopulate();
  });
};

There is a little syntax change: The population separator is still the '.' character, but if you want to set select fields you need to separate them with the ':' character.

Here are some test case and the results:

console.log(JSON.stringify(castPopulate("level1"), null, 4));
console.log(JSON.stringify(castPopulate("level1:field1:field2"), null, 4));
console.log(JSON.stringify(castPopulate("level1,level1.level2.level3:field1:field2"), null, 4));

[
    {
        "path": "level1"
    }
]
[
    {
        "path": "level1",
        "select": "field1 field2"
    }
]
[
    {
        "path": "level1"
    },
    {
        "path": "level1",
        "populate": {
            "path": "level2",
            "populate": {
                "path": "level3",
                "select": "field1 field2"
            }
        }
    }
]

Can you update the package, if you think the code is correct?

[leodinas-hao]

Thanks a lot @robcaa, I'll have a look.

[TobiasDuelli]

Any updates on this @leodinas-hao ?

[leodinas-hao]

First of all, thanks again to @robcaa for providing a way of building deep populate support. However as the proposed approach will impact the existing usage of "populate" given new approach is taking : as the separator for field selection. I'll be looking into if there is a way to support deep populate but not affecting the existing use.

[leodinas-hao]

Any updates on this @leodinas-hao ?

@TobiasDuelli , you're welcome to submit a PR if you have a solution, which doesn't break the existing use.

[leodinas-hao]

Deep populate is supported with new release v1.3.0. Issue closed.