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Date: Wed, 20 Mar 2013 15:08:20 -0300
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Subject: Method check - Can someone create a RFC for it?
From: carlos.vini@gmail.com (Carlos Rodrigues)

Hi,

I'd like to suggest a new functionality for PHP. I don't know the
internals, and i can't create a patch implementing this. I'm writing
here in case someone likes this idea and write a RFC.

We've had a problem recently where one of our developers forgot an "if".

So instead of writing
if ($obj->image) {
echo $obj->image->getUrl();
}

He wrote:
echo $obj->image->getUrl();

Here, locally, it was working cause we had the image. But when we
updated the online version we got a "Fatal error: Call to a member
function getUrl() on a non-object" cause someone didn't upload the
image in one of the records that we're on the home page.

Fatal errors like this can't be catched by a try/catch. And since this
getUrl() was not essential for the page, we'd better output an empty
string then having the site offline.

One might say: "you guys should have tested it better", or "The image
field should be mandatory in the back end."
And it's true, he should have written that extra "if {}".

Examining this problem we happened to stumble open Ruby's and
Coffescript's method check.
Something like this:

$obj->image?->getUrl()?;

So my suggestion is:

Create something like $foo->bar?() or $foo->bar()?, where you don't
care whether the function exists, or if $foo is an object. If it
doesn't exist you just return null.
I guess there are plenty of systems out there where it's better to
output an empty string than having your site offline, just cause the
programmer couldn't test it completely.

Thanks for reading it.

Carlos Rodrigues