Upload images from React Native to LoopBack - react-native

Question

I need to upload a selection of images that user picked from CameraRoll to the LoopBack Component Storage. The thing is that the component storage is working fine, because I can upload and download the files through Postman. But, when I try to upload from react native to loopback, it always returns "No file content upload" with http status 400.
I read a lot of people talking about it and tried everything and none worked for me.
First, I am taking the images from the CameraRoll and my images array looks like this:
[
{
exists: 1,
file: "assets-library://asset/asset.JPG?id=3FF3C864-3A1A-4E55-9455-B56896DDBF1F&ext=JPG",
isDirectory: 0,
md5: "428c2e462a606131428ed4b45c695030",
modificationTime: 1535592967.3309255,
size: 153652,
uri: null
}
]
In the example above I just selected one image.
I transformed to Blob, then I got:
[
{
_data: {
blobId: "3FF3C864-3A1A-4E55-9455-B56896DDBF1F",
name: "asset.JPG",
offset: 0,
size: 153652,
type: "image/jpeg"
}
}
]
So I tried a lot of things after this, tried to send the blob itself as the request body, tried to append to a form data and send the form data, but it doesn't matter the way I try, I always get the "No file content upload" response.
I also tried the example from Facebook, didn't work: https://github.com/facebook/react-native/blob/master/Libraries/Network/FormData.js#L28
The way I am trying now:
In my view:
finalizarCadastro = async () => {
let formData = new FormData();
let blobs = [];
for(let i=0;i<this.state.fotos.length;i++){
let response = await fetch(this.state.fotos[i]);
let blob = await response.blob();
blobs.push(blob);
}
formData.append("files", blobs);
this.props.servico.criar(formData);
}
And the function that send to my server:
criar: (servico) => {
this.setState({carregando: true});
axios.post(`${REQUEST_URL}/arquivos/seila/upload`, servico, {headers: {'content-type': 'multipart/form-data'}}).then(() => {
this.setState({carregando: false});
this.props.alertWithType("success", "Sucesso", "Arquivo salvo com sucesso");
}).catch(error => {
this.setState({carregando: false});
console.log(error.response);
this.props.alertWithType("error", "Erro", error.response.data.error.message);
})
}

Answer 1

I found the solution. So the problem was actually not the code itself, the problem was sending multiple files at the same time. To fix everything, I did this:
this.state.fotos.forEach((foto, i) => {
formData.append(`foto${i}`, {
uri: foto,
type: "image/jpg",
name: "foto.jpg"
});
})
this.props.servico.criar(formData);
And my function that sends the request to the server:
criar: (servico) => {
this.setState({carregando: true});
axios.post(`${REQUEST_URL}/arquivos/seila/upload`, servico).then((response) => {
this.setState({carregando: false});
this.props.alertWithType("success", "Sucesso", "Arquivo salvo com sucesso");
}).catch(error => {
this.setState({carregando: false});
this.props.alertWithType("error", "Erro", error.response.data.error.message);
})
},
So you don't need to set the Content-Type header to multipart/form-data and don't need to transform the images to blob, actually you just need the uri of each one, and I think the type and name attributes are opcional.