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I want to upload file to mongodb with graphql resolver. In server.js I have this help function to store file, which is exported to use it in my resolver. The function is basing on what I found here: https://github.com/jaydenseric/graphql-upload/issues/8), but now some things have changed in graphql. For example destructurising file object. I don’t know what should be found at path variable and how should I use this createReadStream(function which was destructurized from file).
const mongoose = require('mongoose');
const Grid = require('gridfs-stream');
const fs = require('fs');
//...
// Connect to Mongo
mongoose
.connect(process.env.mongoURI, {
useNewUrlParser: true,
useCreateIndex: true,
useUnifiedTopology: true,
useFindAndModify: false
}) // Adding new mongo url parser
.then(() => console.log('MongoDB Connected...'))
.catch(err => console.log(err));
const storeFile = async (upload) => {
const { filename, createReadStream, mimetype } = await upload.then(result => result);
const bucket = new mongoose.mongo.GridFSBucket(mongoose.connection.db, { bucketName: 'files' });
const uploadStream = bucket.openUploadStream(filename, {
contentType: mimetype
});
createReadStream()
.pipe(uploadStream)
.on('error', console.log('error'))
.on('finish', console.log('finish'));
}
module.exports = { storeFile }
//...
My resolver(here it’s minimal version, because now I want only to upload file into my database. In one of my tries, it even created fs.files and fs.chunks collections, but without a data):
Mutation: {
uploadFile: async (_, { file }) => {
console.log(file);
const fileId = await storeFile(file);
return true;
}
}
I have this error now:
Unhandled Rejection (Error): GraphQL error: The “listener” argument must be of type function. Received undefined
and in terminal I have printed ‘error'(like in pipe.on(‘error’, console.log(‘error’) statement )
And I can upload only small files( max 60 kb), all larger just don’t upload, but errors are showing on all tries.
Answer
Ok, I managed to solve it.
resolver mutation:
const { storeFile } = require('../../server');
//...
uploadFile: async (_, { file }) => {
const fileId = await storeFile(file).then(result => result);
return true;
// later I will return something more and create some object etc.
}
supporting function from server.js
const storeFile = async (upload) => {
const { filename, createReadStream, mimetype } = await upload.then(result => result);
const bucket = new mongoose.mongo.GridFSBucket(mongoose.connection.db, { bucketName: 'files' });
const uploadStream = bucket.openUploadStream(filename, {
contentType: mimetype
});
return new Promise((resolve, reject) => {
createReadStream()
.pipe(uploadStream)
.on('error', reject)
.on('finish', () => {
resolve(uploadStream.id)
})
})
}
module.exports = { storeFile }