Upload Images With Aurelia to Express/Multer Api - express

Question

Implementing an Image/File-Upload into my aurelia App. The Express Api works and successfully receives Files and Images using Multer Plugin, tested with Postman.
Now I'm trying to figure out, how to attach the files ot the Aurelia Http/Fetch-Call. Somehow the request is made to the Api, but the images seem not attached. Any Ideas?
Some questions:
Is it correct to attach - in whatever way - the files to the body-key of the request, or do the files need to go seperately?
Is it correct/neccessary to create FormData and to attach the files - in whatever way - to that Obejct?
In what part of the HTTP-Request are the files/images stored, how to identify them serverside (in case my middleware is not working correctly)?
This is my approach so far:
Aurelia-Service:
uploadImagesApi(images) {
let formData = new FormData()
formData.images = images;
return http.fetch(url+"/", {
method: 'put',
body: formData, // <-- Is this correct?
}).then(response => {
return response
}).catch(error => {
console.log("Some Failure...");
throw error.content;
})
}
Input-Element
<input class="input" type="file" files.bind="images" multiple>
<a click.delegate="uploadImagesApi(images)">Upload</a>

Answer 1

uploadImagesApi(images) {
let formData = new FormData()
for (let i = 0; i < images.length; i++) {
formData.append('images', images[i]);
}
return http.fetch(url + "/", {
method: 'put',
body: formData,
})
.then(response => {
return response
})
.catch(error => {
console.log("Some Failure...");
throw error.content;
})
}
make sure your url variable is defined looks like a global

Answer 2

Change formData.images = images; to formData.images = images.item(0);
It might also be required to use 'file' key in formData instead of 'images': formData.file = images.item(o)