(This is a work in process; excuse the pithy nature of this README.)

This package allows you to deep-copy data from a Go variable to another, as long as they are of compatible (but not necessarily identical) types.

For example, you can copy data from a map to a struct:

type testStruct struct {
    Field1 *string `json:"f1" pop:"required"`
    Field2 *int    `pop:"required"`
    Field3 string  `pop:"optional"`
}

s := map[string]interface{}{
    "f1":     "test",
    "Field2": 123,
}

d := testStruct{}

if err := Populate(s, &d); err != nil {
    t.Errorf("%s", err)
}

Popular knows to check for type compatibility, and will perform deep copies into substructures and arrays.

The package uses the pop tag to determine whether it should consider or ignore a field. For structs, field names in the source are computed based on either the destination's field name, or the JSON field name. Unexported fields, fields that do not have a pop tag, and fields that have an empty JSON name (e.g.: json:"-") are ignored.

You can also use the Validate() function to check that a struct contains all the properties marked with a pop:"required" tag. This is handy to perform quick validation, and understands empty values and nil values.

Copyright (c) 2015 MTA Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.