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We've dealt with connection errors but there are other things that could go wrong. Let's see if we can catch the other errors that could happen.
Updates
On line 40 of app.js, to run printError() if there is an error on a request, use the following:
request.on( 'error', error => printError(error) );
Documentation
Let me show you another
error that can occur.
0:00
If you visit my profile endpoint
at teamtreehouse.com/chalkers.json
0:03
we see a beautiful JSON file application,
and we can work with this.
0:09
Well, what about if we go to another
profile that doesn't exist, like
0:14
https://teamtreehouse.com/chalkers-not and
hit Enter.
0:20
There's the text not found.
0:31
The text not found is
not a valid JSON object.
0:32
Let's run the application with
chalkers not as the username.
0:38
And this is the error that's displayed.
0:47
Our application is attempting
to parse the string not found.
0:50
Not found isn't a valid JavaScript object.
0:55
That's why it say's unexpected token,
meaning character n.
0:59
n is the first character
it's trying to parse.
1:08
JSON files start with either an opening
square bracket or curly braces.
1:12
Let's wrap the lines of code
dealing with the parsing and
1:19
printing the message out with a try block.
1:22
Then we can catch the error and
print it out.
1:37
Save the file.
1:51
And then rerun the application
with an invalid username and
1:55
we don't get a stack trace anymore.
1:59
Once again, you can go ahead and include
a more user-friendly message if you want.
2:02
Before we move on to
the next error we handle,
2:08
since we're handling multiple errors,
let's create a function that's
2:11
flexible enough to print out error
messages from an error object.
2:15
Or any other object with
a message property.
2:20
This means if we want to choose to
implement how we handle errors differently
2:23
in the future,
we only have to do it in one place.
2:27
Let's create a function PrintError.
2:39
That takes in one argument error.
2:45
And log out the error message.
2:57
Let's update where all
the console.errors are with printError.
3:00
Awesome.
3:27
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