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PHP screwed me again...

Writing a WordPress plugin this time, as Fletcher might have said,
"You wanna stay away from nonces Gobber, bad news they are."
My code had created a meta-box to allow me to tick / untick a simple check-box against pages and posts so that I could restrict content to registered users. Every time I hit the "update" button I got the lovely little error box telling me there was a problem saving my post and to try again. Thanks WP, very helpful.

Anyway, I tracked the problem to a piece of code that I had transcribed incorrectly from the WP codex page, don't ask me why I hadn't cut and pasted it directly from the page as I normally do, but here's what I had and what I should have had, first the bad code...

wp_nonce_field(
  plugin_basename(
    __FILE__, 'tnjpay_restricted_nonce'
  ),
);

and the correct code is...

wp_nonce_field(
  plugin_basename(__FILE__),
  'tnjpay_restricted_nonce'
);

Simple, but in the cut-and-thrust I just couldn't see that one little mistake; that I had accidentally put the nonce identifier inside the call to plugin_basename instead of as the second parameter to wp_nonce_field. And PHP never said a mumbling word. Thanks PHP.

Admittedly wp_nonce_field takes four parameters and they are all optional so that function I will forgive, but plugin_basename takes one and exactly one parameter but because of the incredibly slack (and useful) way in which PHP lets you pass arguments around, it never complained. Is there some kind of configuration  file setting that would have moaned at me for having given it too much to eat? That would have at least saved some head-scratching! 

If I was being very strict then I would insist that all functions that are not variadic should do this as the first line of code inside the stack frame:

assert(count(func_get_args(), N));

It's a shame that PHP doesn't have a pre-processor. I have used m4 with PHP in the past but on production sites not everybody knows how to use m4 or why it's even useful! Whatever.

I will not make that particular mistake again, at least not today with the WP API.


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