Display image from GridFS

Question

I am trying to read image from GridFS. And getting following error.

var mongoose = require('mongoose');

exports.getLogo = function (req, res, next) {    


    var conn = mongoose.createConnection('localhost', 'database-name', 27017);

    conn.once('open', function () {

        var gs = new mongoose.GridStore(conn.db, 'img1.png', "w");

        gs.read(function (err, data) {

            res.setHeader('Content-Type', gs.contentType);
            res.setHeader('Content-Length', gs.length);
            res.setHeader('Content-Disposition', 'inline; filename="' + gs.filename + '"');

            res.end(data);

        });
    });

};

Error :-

D:\Projects\node_modules\mongoose\node_modules\mongodb\lib\mongodb\db.js:279
          throw err;
                ^
TypeError: undefined is not a function

How to solve this error.

edited -

TypeError: Cannot call method 'length' of undefined
    at Stream.GridStore.read

gridfs-stream output :-

enter image description here

where do you the GridStore code? last time check GridStore is not part of mongoose. both conn and gs need to call open. read the native node.js mongodb doc — wayne, Mar 06 '14 at 05:45
i am using gridFS...http://mongodb.github.io/node-mongodb-native/markdown-docs/gridfs.html — Anup, Mar 06 '14 at 05:47
change var gs = new mongoose.mongo.GridStore(conn.db, 'img1.png', "r"); also read the doc "When GridStore object is created, it needs to be opened". — wayne, Mar 06 '14 at 05:56
thanks..1st error got solved.....i am getting error now `TypeError: Cannot call method 'length' of undefined at Stream.GridStore.read` — Anup, Mar 06 '14 at 06:04

wayne · Answer 1 · 2014-03-06T08:33:14.863

2

you really need to read the doc carefully.

var mongoose = require('mongoose');

exports.getLogo = function (req, res, next) {    


    var conn = mongoose.createConnection('localhost', 'database-name', 27017);

    conn.once('open', function () {

        var gs = new mongoose.mongo.GridStore(conn.db, /* the id */, 'img1.png', "r");
        gs.open(function(err, gs) {
            gs.read(gs.length, function (err, data) {

              res.setHeader('Content-Type', gs.contentType);
              res.setHeader('Content-Length', gs.length);
              // gs don't have a property filename, filename need to come from your req.
              res.setHeader('Content-Disposition', 'inline; filename="' + 'img1.png' + '"');

              res.end(data);

            });
        })



    });

};

edited Mar 06 '14 at 08:33

answered Mar 06 '14 at 06:07

wayne

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11

I used this code...it gives no error...But it doesn't send any response...I do have the specified file in my db... – Anup Mar 06 '14 at 06:16
In Advanced Rest Client...the progress bar keeps moving...! – Anup Mar 06 '14 at 06:17
did the read function callback executed and the data is not null? – wayne Mar 06 '14 at 06:24
what i need here is `binary data` of the `image`.....that is what i need to send as response.... i rechecked again....image is present in db...i also tried with another img...stil data shows `null`. – Anup Mar 06 '14 at 06:33
To open GridStore it require the ObjectId, var gs = new mongoose.mongo.GridStore(conn.db, /* the id */, 'img1.png', "r"); filename is optional. you can specify it in read. It is not very useful then. try this lib https://github.com/aheckmann/gridfs-stream – wayne Mar 06 '14 at 08:34
i am using the same library...it was not giving output so i tried for Gridstore...! – Anup Mar 06 '14 at 08:45
i posted a new question http://stackoverflow.com/questions/22219400/display-image-in-gridfs – Anup Mar 06 '14 at 08:52

Display image from GridFS

1 Answers1