How to upload images via API with Node.js?

Dev
1

This has been asked various times, but none of the solutions so far work for me.

I’m using Node.js to upload images for a post via the API.

I can create posts no problem, but images will not upload.

I convert the image (a png file) into a binary string.

Then I post an application/json request with the API creds in the headers, and a payload like this:

{
   type: "composer",
   synchronous: true,
   file: `${binary_string}`
}

I’ve tried both file as the field name for the file as the API docs say, and also files[] as another post in the Forum suggested.

Using file, I get a 422 with:

undefined method `tempfile' for #<String:0x00007fdfeba2b1d8>

Using files[], I get a 422 error, with “Unprocessable Entity”.

As well as application/json as the docs say, I’ve also tried it as multipart/form-data as the Web UI does and this poster did.

For the form-data post, I did it like this:

 const form = new FormData();
 form.append("type", "composer");
 form.append("synchronous", "true");
 form.append("files[]", this.stringToBinary(file.data!), {
      contentType: file.mimetype,
 });

http.post("/uploads.json", form.getBuffer(), {
  headers: form.getHeaders(),
 }) // creds get added

With this one, with either file or files[], I get a 422 with the error:

undefined method `tempfile' for #<String:0x00007fdfeba2b1d8>

Can anyone help?

2

I got this to work, like this:

import Axios from "axios";
import FormData from "form-data";
import fs from "fs";
const http = Axios.create({
  baseURL: "https://forum.zeebe.io",
  headers: {
    "Api-Key":
      "...",
    "Api-Username": "...",
    "Content-Type": "application/json",
    Accept: "application/json",
  },
});
http.interceptors.request.use((config) => {
  if (config.data instanceof FormData) {
    Object.assign(config.headers, config.data.getHeaders());
  }
  return config;
});

const filename = "/Users/sitapati/Desktop/process.png";
const file = fs.readFileSync(filename);
const form = new FormData();
form.append("files[]", file, {
  filename,
});

http
  .post("/uploads.json", form, {
    params: {
      type: "composer",
      synchronous: true,
    },
  })
  .then(({ data }) => {
    console.info("Response from Discourse", JSON.stringify(data, null, 2));
    return {
      url: data.url,
    };
  })
  .catch((e) => {
    console.error(
      "Error uploading file to Discourse",
      JSON.stringify(e, null, 2)
    );
    throw e;
  });

It also works with a file retrieved from a remote URL, which needs to be retrieved like this:

Axios.get(file.slackUrl, {
   responseType: "arraybuffer",
   headers: { Authorization: "Bearer " + this.slackToken },
})

The key here is: responseType: "arraybuffer".

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