php

PHP warning: Call-time pass-by-reference has been deprecated

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I am getting the warning: Call-time pass-by-reference has been deprecated for the following lines of code:

function XML() {
    $this->parser = &xml_parser_create();
    xml_parser_set_option(&$this->parser, XML_OPTION_CASE_FOLDING, false);
    xml_set_object(&$this->parser, &$this);
    xml_set_element_handler(&$this->parser, 'open','close');
    xml_set_character_data_handler(&$this->parser, 'data');
}
function destruct() {
    xml_parser_free(&$this->parser);
}
function & parse(&$data) {
    $this->document = array();
    $this->stack    = array();
    $this->parent   = &$this->document;
    return xml_parse(&$this->parser, &$data, true) ? $this->document : NULL;
}

What does it cause and how to fix it?

Answers

Remove & from &$this everywhere, it is not needed. In fact, I think you can remove & everywhere in this code - it is not needed at all.

Long explanation

PHP allows to pass variables in two ways: "by value" and "by reference". First way ("by value"), you can't modify them, other second way ("by reference") you can:

     function not_modified($x) { $x = $x+1; }
     function modified(&$x) { $x = $x+1; }

Note the & sign. If I call modified on a variable, it will be modified, if I call not_modified, after it returns the value of the argument will be the same.

Older version of PHP allowed to simulate behavior of modified with not_modified by doing this: not_modified(&$x). This is "call-time pass by reference". It is deprecated and should never be used.

Additionally, in very ancient PHP versions (read: PHP 4 and before), if you modify objects, you should pass it by reference, thus the use of &$this. This is neither necessary nor recommended anymore, as object are always modified when passed to function, i.e. this works:

   function obj_modified($obj) { $obj->x = $obj->x+1; }

This would modify $obj->x even though it formally is passed "by value", but what is passed is object handle (like in Java, etc.) and not the copy of the object, as it was in PHP 4.

This means, unless you're doing something weird, you almost never need to pass object (and thus $this by reference, be it call-time or otherwise). In particular, your code doesn't need it.

Sunday, September 18, 2022

scott_kausler-3060ff090d40

Here's what worked best for me when trying to script this (in case anyone else comes across this like I did):

$ pecl -d php_suffix=5.6 install <package>
$ pecl uninstall -r <package>

$ pecl -d php_suffix=7.0 install <package>
$ pecl uninstall -r <package>

$ pecl -d php_suffix=7.1 install <package>
$ pecl uninstall -r <package>

The -d php_suffix=<version> piece allows you to set config values at run time vs pre-setting them with pecl config-set. The uninstall -r bit does not actually uninstall it (from the docs):

vagrant@homestead:~$ pecl help uninstall
pecl uninstall [options] [channel/]<package> ...
Uninstalls one or more PEAR packages.  More than one package may be
specified at once.  Prefix with channel name to uninstall from a
channel not in your default channel (pecl.php.net)

Options:
  ...
  -r, --register-only
        do not remove files, only register the packages as not installed
  ...

The uninstall line is necessary otherwise installing it will remove any previously installed version, even if it was for a different PHP version (ex: Installing an extension for PHP 7.0 would remove the 5.6 version if the package was still registered as installed).

Monday, December 12, 2022

shankar_damodaran

settype() hasn't been deprecated. Passing by reference at call time has been deprecated. You probably just want to remove the ampersand from in front of the first parameter to your settype() call.

That would be easier to tell for sure if you actually posted your code...

See the manual for more information on references in general, and passing by reference and the deprecation of references in function calls in particular.

Tuesday, August 23, 2022

aravindsagar

You are trying to pass a pointer to your array in array_push. That is why the fatal error is encountered. Simply use:

array_push( $image_set, $images[fname] );

Note: array_push() will raise a warning if the first argument is not an array.

Monday, October 24, 2022

drexiya

Never used any of those, but they look interesting..

Take a look at Gearman as well.. more overhead in systems like these but you get other cool stuff :) Guess it depends on your needs ..

Friday, November 11, 2022

the_falvert

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