NESTED

Simple function to get value from map[string]interface without cast every nest field.

Source

• Nested Source
• Version: 1.2.0
• License: MIT-style

Summary

• About
• how to install
• How to import
• Run Test
• Run Benchmark
• Example
• Documentation

About

Something you need to get value from map and this value is an interface type, you need to cast this value for an type that you know or in nested case you must cast this value and cast for the time that you want.

How to install

go get github.com/rodkranz/nested

How to import

import (
  "github.com/rodkranz/nested"
)

Run test

To run the project test

go test -v --cover

Run benchmark

To run the benchmark

go test -cpuprofile cpu.prof -memprofile mem.prof -bench .

Check benchmark in browser

pprof -http=:8080 cpu.prof

To check this result in browser you must have pprof

Example

Example os input data

data := map[string]interface{}{
    "person": map[string]interface{}{
        "name":  "Rodrigo",
        "level": 3,
    },
    "session": map[string]interface{}{
        "token":  "62vsy29v8y4v248v5y97v1e21v35ce97",
        "expire": "2018-08-08T18:00:00Z",
    },
    "images": map[string]interface{}{},
}

This is the most common usage how to get the name as string type:

personValue, ok := data["person"]
if !ok {
    log.Fatal("There is no person")
}

personMap, ok := personValue.(map[string]interface{})
if !ok {
    log.Fatal("cannot cast value to map")
}

nameInterface, ok := personMap["name"]
if !ok {
    log.Fatal("Person has no name")
}

name, ok := personMap["name"].(string)
if !ok {
    log.Fatal("cannot cast value to string")
}

// name is variable with type string 
fmt.Println("Name is ", name)

If you want to get string name of person you can use:

name, found := nested.String("person.name", data); 
if !found {
	log.Fatal("cannot find name value as string")
}
fmt.Println("Found name", name)

If you want to get int level of person you can use:

level, found := nested.Int("person.level", data); 
if !found {
    log.Fatal("cannot find level value as int")
}
fmt.Println("User is level", level)

If you want to get time.Time expire of person you can use:

{
	expire, found := nested.Time("session.expire", data, time2.RFC3339); 
	if !found {
		log.Fatal("cannot find expire value as time.Time")
	}
	fmt.Println("The token will expire at ", expire)
}
{
	// You can use as 3 parameter a layout of time
	expire, found := nested.Time("session.expire", data, "2006-01-02"); 
	if !found {
	    log.Fatal("cannot find expire value as time.Time with custom layout")
	}
	fmt.Println("The token will expire at ", expire)
}

If you want to get interface images of person you can use:

images, found := nested.Interface("images", data); 
if !found {
	log.Fatal("cannot find images value as interface{}")
}
fmt.Println("Empty map", images)