Debugging in CodeIgniter (and MVC)

Question

Often times I feel the need to dump a variable for debugging purpose. In CodeIgniter I am struggling to do that since I cannot simply "echo" a variable without passing it to the view first, which I think is pain-staking. I have read the official documentation, though I had found a good solution with the log_message function but cannot make it work, even though I successfully made the "logs" folder writable and changed the "threshold" as advised. Any suggestions?

https://www.codeigniter.com/user_guide/general/errors.html

Answer 1

It's not good practice, but you can output anything to the browser at any point in execution (from core classes, libraries, models and controllers) by simply using print_r() at the point you want to output the info.

Of course, this will sometimes not display as there may be redirects/routes/etc that take the user to the next step in the controller execution, but if you want to suppress this (again, for debug purposes only), you can use:

print_r($string_or_variable_to_debug);
die();

The die() command will stop all execution and leave you with just the info you want to output.

Using log_message() is better practice, but it's difficult to understand why you're not having success there if you say you've followed the following steps:

1. Make sure that your logs folder is set to be writable
2. Set $config['log_threshold'] to 2, 3 or 4
3. Used the function like so: log_message('debug','Message you want to log');

If you want to use print_r() to nicely format an array or object inside the log message, then you'll need to set the second parameter of print_r() to TRUE, like so:

log_message('debug',print_r($array_or_object,TRUE));