File uploading ​

Axe API doesn't provide file-uploading helpers. But we will create documentation here to describe how it is easy to add file uploading support to your API.

• You will learn
• How to upload files?
• How to handle files?
• How to send a file upload request to the server?

Getting started ​

File uploading is an important part of APIs. You can use many different techniques and methods. Since Axe API is actually an Express.js framework under the hood, we are going to use the internal parts of Express.js.

Installing dependencies ​

First of all, let's install the dependencies. We are going to use the multer library.

$ npm install --save multer

Adding multer ​

We should add the multer library as a middleware to Express.js. To be able to do that, we should apply the following changes;

import { Express } from "express";
import bodyParser from "body-parser";
import multer from "multer";

const onBeforeInit = async (app: Express) => {
  const forms = multer();
  app.use(bodyParser.urlencoded({ extended: true }));
  app.use(forms.array("file"));
};

const onAfterInit = async (app: Express) => {};

export { onBeforeInit, onAfterInit };

Handling files ​

After the multer middleware, we are ready to handle files. Let's assume that we have a User model and we are going to upload files in the creating new user.

We should create the following hook file;

import { IHookParameter, ApiError } from "axe-api";

export default async ({ formData, req }: IHookParameter) => {
  const file = ((req.files || []) as any[]).find(
    (item) => item.fieldname === "file"
  );

  if (!file) {
    throw new ApiError("The file parameter is required!");
  }

  // TODO: upload file in anywhere like AWS S3, etc.

  // set the path to the original formData
  formData.path_name = "s3://filename.jpg";
};

In this file, we are able to access the uploaded file data via req.files variable thanks to multer library.

After that, you can upload the file wherever you want. Also, you can set the user's model data to be saved for the file location.

Sending request ​

The only change is the request type.

You should send the file to the Axe API server like the following example;

$ curl --location 'localhost:3000/api/v1/users' \
  --form 'file=@"/Users/my-user/Download/axe-api.png"' \
  --form 'name="John"' \
  --form 'surname="Locke"'

Next steps ​

In this section, we simply demonstrate a file-uploading example. You can use many different methods like you are using a simple Express application.

In the next section, we are going to discuss about Authentication.