cborquery

Overview

This is a XPath query package for parsing and querying Concise Binary Object Representation (CBOR) messages using the xpath package. The query package is writing in pure go.

cborquery helps you easily and flexibly extract data from CBOR messages using XPath queries without using pre-defined object structures.

Install Package

go get github.com/srebhan/cborquery

Get Started

Below is some example code to show how to use the package. Here we expect a message similar to the following JSON data

{
    "person":{
        "name":"John",
        "age":31,
        "female":false,
        "city":null,
        "hobbies":[
            "coding",
            "eating",
            "football"
        ]
    }
}

Using the xpath syntax you are able to access specific fields of a CBOR message

package main

import (
	"fmt"
	"strings"

	"github.com/srebhan/cborquery"
)

func main() {
    // Get a CBOR message from somewhere
    buf, err := os.ReadFile("mymessage.cbor")
	if err != nil {
		panic(err)
	}

    // Parse the message to be able to query the data
	doc, err := cborquery.Parse(bytes.NewBuffer(s))
	if err != nil {
		panic(err)
	}

	// xpath query
	age := cborquery.FindOne(doc, "age")
	// or
	age = cborquery.FindOne(doc, "person/age")
	fmt.Printf("%#v[%T]\n", age.Value(), age.Value())

	hobbies := cborquery.FindOne(doc, "//hobbies")
	fmt.Printf("%#v\n", hobbies.Value())
	firstHobby := cborquery.FindOne(doc, "//hobbies/*[1]")
	fmt.Printf("%#v\n", firstHobby.Value())
}

Iterating over the content

package main

import (
	"fmt"
	"strings"

	"github.com/srebhan/cborquery"
)

func main() {
    // Get a CBOR message from somewhere
    buf, err := os.ReadFile("mymessage.cbor")
	if err != nil {
		panic(err)
	}

    doc, err := cborquery.Parse(strings.NewReader(s))
	if err != nil {
		panic(err)
	}
	// iterate all json objects from child ndoes.
	for _, n := range doc.ChildNodes() {
		fmt.Printf("%s: %v[%T]\n", n.Data, n.Value(), n.Value())
	}
}

For more information on XPath and supported features and function see https://github.com/antchfx/xpath