gron

gron

The gron go cli tool is very cool, and I've discovered some uses for the conversion between gron and json in some other code, so I wanted to make the functionality reusable as an importable module, rather than simply pull the go files into the various projects.

Usage

The interface for the this uses .ToGron() and .ToJSON() to represent the gron and ungron methods of the original cli tool.

We create a gron instance by passing an io.Reader and an io.Writer.

func NewGron(reader io.Reader, writer io.Writer) *Gron

When we are wanting to manipulate the output data, we aren't likely to pass an io.Writer that outputs to anything other than a byte buffer to capture the data to a variable. Though we can simply pass an io.Writer that writes to stdout similar to the way the cli tool does with colorable.NewColorableStdout().

Pull down the module

go get github.com/maahsome/gron

Example for .ToGron()

package main

import (
    "bytes"
    "fmt"
    "strings"
    "github.com/maahsome/gron"
)

func main() {

    // json object to gron
    jsonData := `{
"book":[
    {
        "id":"444",
        "language":"C",
        "edition":"First",
        "author":"Dennis Ritchie"
    },
    {
        "id":"555",
        "language":"C++",
        "edition":"Second",
        "author":"Bjarne Stroustrup"
    }
]
}
`
    reader := strings.NewReader(jsonData)
    out := &bytes.Buffer{}
    ge := gron.NewGron(reader, out)
    ge.SetMonochrome(true)
    err := ge.ToGron()
    if err != nil {
        fmt.Println(err)
    }
    // Our out variable now contains the gron notation lines, we can work with
    // that data.
    // We will output the data to verify that the data was generated as expected.
    fmt.Println(out)
}

Example for .ToJSON()

package main

import (
    "bytes"
    "fmt"
    "strings"
    "github.com/maahsome/gron"
)

func main() {
    // gron object to ungron
    gronData := `json = {};
json.book = [];
json.book[0] = {};
json.book[0].author = "Dennis Ritchie";
json.book[0].edition = "First";
json.book[0].id = "444";
json.book[0].language = "C";
json.book[1] = {};
json.book[1].author = "Bjarne Stroustrup";
json.book[1].edition = "second";
json.book[1].id = "555";
json.book[1].language = "C++";
`

    reader := strings.NewReader(gronData)
    out := &bytes.Buffer{}
    ge := gron.NewGron(reader, out)
    ge.SetMonochrome(true)
    err := ge.ToJSON()
    if err != nil {
        fmt.Println(err)
    }

    // Our out variable contains json, which we can manipulate as we need.
    // We will just output to see that everything worked as expected.
    fmt.Println(out)
}