I'm using grid-stream and girdFsStorage library for getting image from mongodb.
I uploaded image to db was okay, but when I tried to get image from db failed.
I expected db.collection at gfs.files.findOne({ filename: req.params.filename }, (err, file) => {...}
but, this.db.collection is returned.
any ideas?
TypeError: this.db.collection is not a function
Here is my db connect
let db = mongoose.connect(init.mongoUrl)
.then(() => console.log('Connected to MongoDB...'))
.catch(err => console.error(('Could not connect to MongoDB...\n'), err))
and this is my code for getting an image from db
// Init stream
const gfs = Grid(db, mongoose.mongo);
api.get('/image/:filename', (req, res) => {
gfs.files.findOne({ filename: req.params.filename }, (err, file) => {
// Check if file
if (!file || file.length === 0) {
return res.status(404).json({
err: 'No file exists'
});
}
// Check if image
if (file.contentType === 'image/jpeg' || file.contentType === 'image/png') {
// Read output to browser
const readstream = gfs.createReadStream(file.filename);
readstream.pipe(res);
} else {
res.status(404).json({
err: 'Not an image'
});
}
});
});
It was because I didn'use
gfs.collection('uploads');
on .once('open', () => {...})
// Init gfs
let gfs;
conn.once('open', () => {
// Init stream
gfs = Grid(conn.db, mongoose.mongo);
gfs.collection('uploads');
});
You can see my example here:
https://github.com/qkreltms/mongodb_simple_file_upload_to_db_example/blob/master/app.js
about .collection() :
https://github.com/aheckmann/gridfs-stream/blob/c394e050d066a5c81c6dcdddad186b08a93d5f1f/lib/index.js#L75
Related
I have the below code which is binding to an LDAP server and I want to return the user that I have added "ab" within the "interviewees" group (code taken from ldapjs client api page). I can see I am getting back a response from the server with the expected EventEmitter object. I am expecting to see information about the user when calling logging console.log() on the searchEntry object. I appear to have no searchEntry objects. Is my DN for my user correct? I am currently unsure whether the issue is with my query and I am not getting any data back or whether I am failing to process the response correctly?
const client = ldap.createClient({ url: 'ldap://' + LDAP_SERVER + ':' + LDAP_PORT });
// Connect and bind to the Active Directory.
const connectToClient = async () => {
const secret = LDAP_SECRET_KEY;
return await new Promise((resolve, reject) => {
client.bind(LDAP_USER, secret, function (err, res) {
if (err) {
console.error(err);
reject('Failed to connect to LDAP server');
} else {
resolve('Connected to LDAP server');
}
});
});
};
onst searchADForUser = async () => {
return await new Promise((resolve, reject) => {
client.search('CN=ab,OU=interviewees,OU=Users,OU=interview,DC=interview,DC=workspace,DC=com', function (err, res) {
if (err) {
console.error(err);
reject('Error searching LDAP server');
} else {
res.on('searchEntry', function (entry) {
console.log('entry: ' + JSON.stringify(entry.object));
});
res.on('searchReference', function (referral) {
console.log('referral: ' + referral.uris.join());
});
res.on('error', function (err) {
console.error('error: ' + err.message);
});
res.on('end', function (result) {
console.log('status: ' + result.status);
});
resolve(res);
}
});
});
};
const handler = async (event) => {
try {
return responses.success(
await connectToClient().then(async function(event) {
console.log(event);
await searchADForUser().then(function(event) {
console.log(event);
}).catch(function(event) {
console.log(event);
})
}).catch(function(event) {
console.log(event);
})
);
} catch (err) {
console.error(err);
return responses.error(err);
} finally {
client.unbind();
}
};
The active directory structure is below
The central issue I was having was understanding how to process the returned EventEmitter object from the search function. I need to add to an array on each searchEntry event and then return that entry in my resolve callback function only once the end event had occurred. The code above was calling resolve immediately and hence no searchEntry events or the end event had been processed yet.
Code I am now using below:
function (err, res) {
if (err) {
console.error(err);
reject(new Error('Error retrieving users from Active Directory'));
} else {
const entries = [];
res.on('searchEntry', function (entry) {
entries.push(entry);
});
res.on('searchReference', function (referral) {
console.log('referral: ' + referral.uris.join());
});
res.on('error', function (err) {
console.error('error: ' + err.message);
});
res.on('end', function (result) {
console.log('status: ' + result.status);
if (result.status !== 0) {
reject(new Error('Error code received from Active Directory'));
} else {
resolve(entries);
}
});
}
}
I want to create a static function on a mongoose "log" module, which would allow me to write a message as a log entry.
How do I access the model from within the static function? Can I use this.model like below? I don't want to simply use native MongoDB insert command, because I want the model to validate the input, etc.
// ... schema defined above...
var Log = mongoose.model('Log', LogModelSchema)
Log.statics.log = function(message) {
var x = new this.model({message: message})
x.save()
.then(() => { .. do something .. }
.catch((err) => { .. handle err .. }
}
Is this the way it's supposed to be done?
You can make it work like this using this.create:
const mongoose = require("mongoose");
const logSchema = new mongoose.Schema({
message: String
});
logSchema.statics.log = function(message) {
this.create({ message: message })
.then(doc => console.log(doc))
.catch(err => console.log(err));
};
module.exports = mongoose.model("Log", logSchema);
Now you can use this in your routes like this:
Log.log("test");
or just return promise from statics:
logSchema.statics.log = function(message) {
return this.create({ message: message });
};
And use like this:
const Log = require("../models/log");
router.get("/log", (req, res) => {
Log.log("test")
.then(result => {
console.log(result);
res.send("ok");
})
.catch(err => {
console.log(err);
res.status(500).send("not ok");
});
});
I successfully coded to upload a image upload into the MongoDB. But now i want to upload multiple images into database. i used gridFS and multer. Can someone help me out to solve this problem
// Create Storage engine
var storage = new GridFsStorage({
url: Mongo,
file: (req, file) => {
return new Promise((resolve, reject) => {
crypto.randomBytes(16, (err, buf) => {
if (err) {
return reject(err);
}
const filename = buf.toString('hex') + path.extname(file.originalname);
const fileInfo = {
filename: filename,
bucketName: 'uploads',
metadata: {'username': req.body.username}
};
resolve(fileInfo);
});
});
}
});
const upload = multer({ storage });
/*--------------------------------------------------------*/
app.get('/',(req,res)=>{
gfs.files.find().toArray((err,files)=>{
// Check if Files
if(!files || files.length ===0)
{
res.render('index',{files:false});
} else{
files.map(file=>{
if(file.contentType === 'image/jpeg' || file.contentType ===
'image/png')
{
file.isImage = true;
} else {
file.isImage = false;
}
});
res.render('index',{files:files});
}
});
});
/*----------------------------------------------------*/
// Display Image
app.get('/image/:filename', (req,res)=>{
gfs.files.findOne({filename: req.params.filename}, (req,file) =>{
// Check if File
if(!file || file.length ===0)
{
return res.status(404).json({
err: 'No files exist'
});
}
// Check if image
if(file.contentType === 'image/jpeg' || file.contentType === 'image/png')
{
// Read output tp browser
var readstream = gfs.createReadStream(file.filename);
readstream.pipe(res);
}
else
{
res.status(404).json({
err: 'Not an image'
});
}
});
});
i attached code section which is related to image upload. please check this code and give a good trick to upload multiple images to mongoDB
I have the following defined in my server.js,
//server.js
var mongoose = require("mongoose");
var Schema = mongoose.Schema;
var userSchema = new Schema({
"userName": {
type: String,
unique: true
},
"password": String,
"loginHistory": [{
"userAgent": String,
"dateTime": Date
}]
});
var User;
module.exports.initialize = () => {
return new Promise(function (resolve, reject) {
let db = mongoose.createConnection("mongodb://<dbuser>:<dbpassword>#ds237409.mlab.com:37409/web322_a6");
db.on('error', (err)=>{
reject(err); // reject the promise with the provided error
});
db.once('open', () => {
User = db.model("users", userSchema);
resolve();
});
})
};
I have a function that is called when posting to my app.post('/register') route, and it basically builds a new User, then assigns it to the passed data, and resolves it afterwards.
module.exports.registerUser = (userData) => {
return new Promise((resolve, reject) => {
if (userData.password != userData.password2) {
reject("Passwords do not match!");
}
let newUser = new User(userData);//<!-- 'Error: TypeError: User is not a constructor'
newUser.save((err) => {
if(err.code == 11000) {
reject("Username already taken");
} else {
reject("Error creating User: " + err);
}
// exit the program after saving
//process.exit();
resolve();
});
})
}
At first I thought I've misdefined User, but I seem to have initialized it properly, as per the MongoDB documentation. Any thoughts? It keeps throwing Error: TypeError: User is not a constructor
EDIT: /post / register
app.post("/register", (req, res) => {
console.log("entering1");
dataServiceAuth.registerUser(req.body).then((data) => {
res.render('register', {successMessage: "User Created"});
}).catch((err) => {
console.log("Error: " + err);
res.render('register', {errorMessage: err, userName: req.body.userName});
})
});
My error was in,
let db = mongoose.createConnection("mongodb://<dbuser>:<dbpassword>#ds237409.mlab.com:37409/web322_a6");
The greater than and less than signs are not to be used. Proper string:
let db = mongoose.createConnection("mongodb://dbuser:dbpassword#ds237409.mlab.com:37409/web322_a6");
I'm writing an a async function with ES6 promises, that 1) saves the query parameters for a user 2) fetches data from mongodb using mongoose, 3) manipulates the json into a DSL, 4) and queries another db with it.
mongoose": "^4.7.7"
//myController.js
const myQuery = require('../models/myQuery_model');
require('mongoose').Promise = global.Promise
const uuidV4 = require('uuid/v4');
exports.saveNewQuery = function(req, res, next) {
const rawQuery = req.body;
const queryToStore = new myQuery(rawQuery);
const uid = uuidV4();
const queryToStore.uid = uid
queryToStore.save().then(() => {
fetchQueryFromMongo(uid);
}).then((storedQuery) => {
compileQueryToString(storedQuery);
}).then((queryString) => {
fetchResultsFromOtherDb(queryString);
}).then((results) => {
res.json({ results });
}).catch((error) => {
console.log(error)
})
}
Currently I'm not able to resolve the response from mongodb step 2. Still, the controllter goes on to compileQueryToString rather than catch the error from fetchQueryFromMongo
// fetchQueryFromMongo.js
const myQuery = require('../models/myQuery');
require('mongoose').Promise = global.Promise
module.exports = (uid) => {
return new Promise(
(resolve, reject) => {
myQuery.find({ uid }).then((err, res) => {
if (err) {
reject(err);
}
console.log('response success!')
resolve(res);
});
}
);
};
I'm new to promises so any tips / suggestions would be appreciated!
Make sure to return a value from your then handlers. The code below does this by using the concise body form of arrow functions.
queryToStore.save()
.then(() => fetchQueryFromMongo(uid))
.then(storedQuery => compileQueryToString(storedQuery))
.then(queryString => fetchResultsFromOtherDb(queryString))
.then(results => res.json({ results }))
.catch(console.log);