Saturday, August 21, 2010

Something on CakePHP Notice (8): Undefined Index

I do not know what should be the perfect title for this post - amazing cake or uncanny cake. But unfortunately, CakePHP can literally drive you CRAZY at times. So, we need to develop a methodical debugging algorithm for cake.


Settings:

1. You are using proper Model/ Controller/ View setup.
2. You are firing correct SQL statement to fetch records. And database has at least one matching record.
3. Everything is just fine to the best of your knowledge and yet you don't really see any output in your view file.


To debug:


1. Set debug level to '2'.
As such my localhost is configured in that format by default. So, I do not have to change that setting too often. 



2. Read the output in the debug mode very carefully. Here lies the clue.
If you see a message like: 
Notice (8): Undefined index .. blah blah blah
CakePHP points out exactly what went wrong with the filename and line number even. This output is very reliable. "Undefined index" means you have used a variable somewhere but it has not been assigned any value. In production mode, CakePHP will ignore this warning and you will see nothing in your webpage leading to complete confusion.


3. You are more likely to fix the problem by correcting small typos in that specified file. Anyway, if you can't find anything wrong, follow the next few steps.

Check the value of the fetched recordset using debug($data) in your controller/action.
If you can see the values as per expectation, move on to your view files.
If you can't see any result, re-frame your find() conditions, examine your controller/action statements very carefully.

4. Check for typos.
Your variable names must be the same in controller set up and view files. Variable names you might have used in views without setting its value in the controller first. And remember the auto magic cake feature, which automatically converts controller variable names like:
my_funny_vars
to:
myFunnyVars

So, in your view file, you need to mention myFunnyVars and not my_funny_vars.
I wasted more than few hours to fix that.

5. Few other tips I have found elsewhere:
When using scaffolding the order your associations must be the same as the order of the keys in your table to avoid getting this error message. Thankfully, I did not face that problem till now.

6. Have confidence in your cake knowledge. Keep your cool. And move methodically (check for view files, then controller setup, and finally your great models). If you can see desired result using debug($data) in your controller, problem is really trivial. To get into the details, you can use debug($data) in your view file to trace out the contents of the array elements as well.

Sounds too complicated? That's how CakePHP goes on.
Hope it helps someone, who might have been stumbling with Notice (8): Undefined index!!!

9 comments:

Evan R. Murphy said...

Nice post. While I haven't gotten to the bottom of this cryptic Notice (8): Undefined Index yet, you've given me some ideas. (Also, it just helps to have someone to commiserate with. ;)

my-cakephp said...

Thanks Evan.

almeda said...

I recently came across your blog and have been reading along. I thought I would leave my first comment. I don't know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.
cakephp development

my-cakephp said...

As such, I started this blog as a reference for my personal help on CakePHP. I am glad to see you liked it. Please, visit again. Thanks.

Aaricevans said...

I have seen a extremely informative blog. Truly I like this blog. This blog gives us especially excellent knowledge about CakePHP.
cakephp development

Siddhartha said...

Thanks a lot dude...
:) :) :)

WR said...

Hey I have got data in my variable using foreach($report as &rep)

note it is getting things from 4 different table in database

Now when I print my $rep I get the following:

Array
(
[Report] => Array
(
[id] => 246
[emp] => werock
[name] => werock
[organization] => cakephp
[customer] => great
)

[file] => Array
(
[0] => Array
(
[id] => 211
[report_id] => 246
[file_name] =>
[file_type] =>
[file_size] => 0
[file_error] => 4
[file_tag] => 0
)

)

[Engineer] => Array
(
[0] => Array
(
[id] => 232
[report_id] => 246
)

)

[Issue] => Array
(
[0] => Array
(
[id] => 118
[report_id] => 246
[date_created] => 2012-02-10
[status] => wait
)

[1] => Array
(
[id] => 119
[report_id] => 246
[date_created] => 2012-02-10
[status] => debug
)

[2] => Array
(
[id] => 120
[report_id] => 246
[date_created] => 2012-02-10
[status] => Completed

)

)

)



Now what I want to do is access Issues array and check how many array are there in it. in this case 3(0,1,2). and print the value of status.

But when I do $rep['Issue']['status'] I get Undefined index: status. Can you tell me where I might be going wrong.

Siddhartha said...

@WR, I'm not quite sure what you meant.

But it looks like $rep['Issue'] is also an array. So, loop through its content like:

foreach ($rep['Issue'] as $repIssue):

debug($repIssue['status']);

endforeach;

I hope it helps.

Best Regards,
Sid



So, you could try looping through

cisekta said...

Thanks for explaining in such a wonderful way. CakePHP has lot of things in it and as CakePHP developer, one must be aware about this..