Powerful Command-Line Applications in Go/

...

/

Adding an Item

Adding an Item

Learn how to include the functionality to add new items in a to-do list.

We'll cover the following...

Overview

So far, our to-do REST API client is able to get all the items from the list and view details about specific items. Let’s include the ability to add new items to the list so users can track their new tasks.

To add new tasks to the to-do list using our REST API, the client must send an HTTP POST request to the /todo endpoint containing the task as a JSON payload. As usual, we obtain this information from the API’s documentation to understand their requirements.

Updating the cmd/client.go file

Let’s define the logic to send the HTTP POST requests in the cmd/client.go file. We edit this file and update the import section by including two new dependencies:

  • The bytes package to use a buffer of bytes as the content body.
  • The io package to use the io.Reader interface.
import (
  "bytes"
  "encoding/json"
  "errors"
  "fmt"
  "io"
  "io/ioutil"
  "net/http"
  "time"
)
Importing the required list

To create an item, we have to send the HTTP POST request to add a new item, and we’ll also send other types of requests to complete and delete items. Instead of defining a function that only sends the POST request, we’ll use the same approach we used to develop the getItems() function by defining a more generic function sendRequest() that can send many different requests and then using it in a more specific function addItem() that sends the specific request to add a new item to the list.

Defining the sendRequest() function

This function takes as input the url as a string to send the request to, the method as a string representing the HTTP method to use in the request, the contentType as a ...