Query for object subset

Documents can become quite large after a while. But if only a small part of the document is needed, it creates unnecessary load. This parser can be used to generate a subset by means of a query. This would allow the API to return only the required data. E.g. the roles of a user.

The language

The syntax of this language is simple: path.field_name=subset_field_name. You can concatenate fields to a subset with the separator , e.g. contact.email=email,contact.phone=phone to get the subset like {email: "___", phone: "___"}.

Example

import (
	"github.com/StevenCyb/goapiutils/object/subset"

	"go.mongodb.org/mongo-driver/mongo/options"
)
// ...

  subsetExpression := r.URL.Query().Get("subset")

  // ...

  parser := subset.NewParser(nil)
  resultDataSubset, err := parser.Parse(subsetExpression, resultData)

  // ...
  
  json.NewEncoder(w).Encode(resultDataSubset)