error agent is a module help you deal with the errors, and respond them to http client
npm install error-agent
when dealing with errors, many people simply use string, instead of Error object, which is not appropiate
you need to use Error object, attached with some properties, so you know how to deal with it later
so, when you're in async code
var errorAgent= require('error-agent');
DB.queryUser(function(err, userData){
if(!userData.auth) //if this user is not authenticated to read this page
callback( errorAgent.handle({ status: 403, msg: 'you need to sign in to see' }) ) //callback an error
})
or simply throw
if(!userData.auth)
throw errorAgent.handle({ status: 403, msg: 'you need to sign in to see' });
as you might guess, errorAgent.handle
return an Error object
with the properties you pass in
you should call it at your last callback
and pass the error object to use
, pass req
, res
to send
it will deal with it for you
errorAgent.send(err, req, res);
you can use code property, so you can register a function to deal with certain error code
if(user.hasNoName)
throw errorAgent.handle({code: 'USER_NONAME'});
register a code error handler first
ErrorAgent.register('USER_NONAME', function (req, res) {
res.send('you got no name!');
});
just give a file path, that will exports error code handlers
would be better
ErrorAgent.config({ codesPath: __dirname + '/errors.js' })
- error page folder path