Nodejs Firebase Callback Function Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers
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Navaneetha Krishnan K
May 12, 2020, 12:09:45 PM5/12/20
to Firebase Google Group
Hi All I'm a Newbie to Nodejs and Firbase as well.
I have a written a firebase function to save the data to Firebase DB VIA Firebase-Admin SDK.
But It always returns a error if I add a callback function
Error : Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
The Code is working fine if there is no callback function attached to the Firebase Function.
Working Code :
app.post('/add_project_status', function(req, res)
{
var status_id = Math.floor(new Date().getTime() / 1000);
var status_name = req.body.status_name.trim();
var status = req.body.status;
try
{
if (status != undefined)
{
status = 1;
}
else
{
status = 0;
}
if (status_id != '' && status_name != '')
{
var db = admin.database();
var ref = db.ref("status/" + status_id);
ref.set(
{
status_name: status_name,
status_id: status_id,
status: status
});
}
}
catch (error)
{
console.log("Data could not be saved." + error);
}
});
Error Code :
app.post('/add_project_status', function(req, res)
{
var status_id = Math.floor(new Date().getTime() / 1000);
var status_name = req.body.status_name.trim();
var status = req.body.status;
try
{
if (status != undefined)
{
status = 1;
}
else
{
status = 0;
}
if (status_id != '' && status_name != '')
{
var db = admin.database();
var ref = db.ref("status/" + status_id);
ref.set(
{
status_name: status_name,
status_id: status_id,
status: status
}, function(error)
{
if (error)
{
// console.log(" eoorr");
}
else
{
console.log(" suceess");
}
});
}
}
catch (error)
{
}
});
If I add this call back function code to firebase
var db = admin.database();
var ref = db.ref("status/" + status_id);
ref.set(
{
status_name: status_name,
status_id: status_id,
status: status
}, function(error)
{
if (error)
{
// console.log(" eoorr");
}
else
{
console.log(" suceess");
}
});
It gives me a Error
Error :
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client at ServerResponse.setHeader (_http_outgoing.js:526:11) at ServerResponse.header (G:\xampp_new\htdocs\saiby\public\node_modules\express\lib\response.js:771:10) at ServerResponse.contentType (G:\xampp_new\htdocs\saiby\public\node_modules\express\lib\response.js:599:15) at ServerResponse.send (G:\xampp_new\htdocs\saiby\public\node_modules\express\lib\response.js:145:14) at done (G:\xampp_new\htdocs\saiby\public\node_modules\express\lib\response.js:1008:10) at tryHandleCache (G:\xampp_new\htdocs\saiby\public\node_modules\ejs\lib\ejs.js:261:5) at View.exports.renderFile [as engine] (G:\xampp_new\htdocs\saiby\public\node_modules\ejs\lib\ejs.js:461:10) at View.render (G:\xampp_new\htdocs\saiby\public\node_modules\express\lib\view.js:135:8) at tryRender (G:\xampp_new\htdocs\saiby\public\node_modules\express\lib\application.js:640:10) at Function.render (G:\xampp_new\htdocs\saiby\public\node_modules\express\lib\application.js:592:3)
can some one help me what has to be modified or removed from the piece of code to avoid this issue. TIA .
Kato Richardson
May 13, 2020, 3:17:43 PM5/13/20
to Firebase Google Group
Hello Navaneetha,
The snippet you've provided here is incomplete and can't help us diagnose what you've described; there would be some code elsewhere causing that issue. See how to ask for some advice on providing the correct details for troubleshooting.
Once you call send() or next() in express, you can't call .status(), .send(), or .end() again. Keep in mind that the database calls are asynchronous, so if you have code after them calling one of those, then the code inside will likely be triggered after that.
Also make sure that you are passing your express app into the Functions http.onRequest() method similar to this example.
☼, Kato
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