Bump PHP requirement to PHP 5.3.0 minimum

[thekid]

Scope of Change

The minimum PHP requirement for the XP Framework master branch will be bumped from 5.2.10 (5.2.0 unofficially also worked!) to 5.3.0.

Rationale

This will enable us to work with namespaces, get_called_class(), static, and remove various PHP 5.2.x workarounds.

Functionality

Namespace adoption

We can possibly go farther than just supporting optional namespaces as described in RFC #222.

Problem: Namespaces and extension methods

Prior to namespaces, all classes used inside a class needed to be "used" via the uses statement. This would trigger the __import($scope) initializer. Imaging an Example class and and ExampleExtensions class - the latter providing an isEmpty() method.

uses('com.example.Example', 'vendor.ExampleExtensions', 'unittest.TestCase');

class ExampleUsageTest extends TestCase {
  #[@test]
  public function is_empty() {
    $this->assertTrue(create(new Example())->isEmpty());
  }
}

Now if we rewrite this to namespaces, the ExampleExtensions class' import initializer wouldn't necessarily be called any more, even if it existed inside a use statement, since that only triggers the autoloading mechanism if the class isn't defined! To work around this, we can re-add the uses() call, making things look funny because we now have mixed use and uses() statements.

A possible solution could be to add a thin wrapper to uses called import, resulting in the following picture:

use \com\example\Example;
use \unittest\TestCase;
import('vendor.ExampleExtensions');

class ExampleUsageTest extends TestCase {
  #[@test]
  public function is_empty() {
    $this->assertTrue(create(new Example())->isEmpty());
  }
}

Enum simplification

Enums can be declared with much less code - see xp-framework/xp-framework#229.

Named pipes

This could be removed:

core/src/main/php/rdbms/mysqlx/NamedPipe.class.php

  // Workaround for PHP bug #29005: "fopen() can't open NT named pipes on local
  // computer".
  if (0 === strncmp('\\\\.', $socket, 3)) {
    $socket= '\\\\127.0.0.1'.substr($socket, 3);
  }

Ternary shortcut

We could start using the ternary shortcut ?:.

Anonymous functions

We could (and should) investigate places where anonymous functions make sense in the XP Framework. An example of this would be in a REST client implementation:

  $request= create(new RestRequest('/resource/{id}'))->withSegment('id', $id);
  $response= $this->send($request, array(
    200 => function($result) { return $result->data('type.of.Resource'); }
    404 => function($result) { return NULL; }
  ));

Static "no such method" handler

Inside our root objects Object and Throwable, we have a __callStatic() implementation, which could be simplified as follows:

- $t= debug_backtrace();
- throw new Error('Call to undefined method '.$t[1]['class'].'::'.$name);
+ throw new Error('Call to undefined method '.get_called_class().'::'.$name);

Directory of current file

We can remove occurrences of dirname(__FILE__) and replace them with __DIR__.

System

We can change the lang.System class to use gethostname() inside System::getProperty('host.name') instead of having to rely on either the posix extension or environment variables.

Security considerations

None.

Speed impact

Better. 🐝

Dependencies

PHP 5.3.0

Related documents

• http://php.net/releases/5_3_0.php - PHP 5.3.0 Release Announcement, 30-Jun-2009

[thekid]

An idea for using closures in the framework would be to add exception assertions to the unittest library (see also http://nunit.com/index.php?p=exceptionAsserts&r=2.5 ):

Example:

$this->assertException('lang.IllegalArgumentException', function() {
  throw new IllegalArgumentException('Test');
});

Implementation: https://github.com/thekid/xp-framework/compare/assert-exception

[thekid]

Another idea would be adding ARM - automatic resource management - blocks support (see also http://news.planet-xp.net/article/397/2010/12/31/ - but using a different word since try already is a PHP keyword and we can't recycle it):

Example:

using($in= $origin->getInputStream(), $out= $target->getOutputStream(), function() use($in, $out) {
  while ($chunk= $in->read()) {
    $out->write($chunk);
  }
});

Implementation (without error handling, which would be need to be added): https://github.com/thekid/xp-experiments/blob/master/arena/five3/lambda/using.php

[thekid]

The util.profiling.Timer class could be extended to run a block:

$t= new Timer();

// Old
$t->start();
for ($i= 0; $i < 100000; $i++) {
  // ...
}
$t->stop();

// New
$t->measure(function() {
  for ($i= 0; $i < 100000; $i++) {
    // ...
  }
});

Console::writeLinef('Elapsed time: %.3f seconds', $t->elapsedTime());

[thekid]

import('vendor.ExampleExtensions');

Another idea would be something like import> new Extension('vendor.ExampleExtensions');, see here. The same technique could be used to create the following:

// #1
use \vendor\Example;
new import('\vendor\ExampleExtensions');

// #2
use \vendor\Example;
new import('\vendor\ExampleExtensions', __NAMESPACE__);

// #3, PHP 5.5 only
use \vendor\Example;
new import(\vendor\ExampleExtensions::class);

Advantage: new and use visually align nicely.

[thekid]

• ChangeLog entry written
• Travis 5.2 build deactivated

See xp-framework/xp-framework@193b2d1

[thekid]

• Use get_called_class() instead of debug_backtrace()

See xp-framework/xp-framework@e383fb9

[thekid]

• Remove workaround for missing ReflectionProperty::setAccessible().

See xp-framework/xp-framework@86b05df and xp-framework/xp-framework@1614396

Note: ReflectionMethod::setAccessible() didn't surface until 5.3.2, so we need to keep the workaround until we bump the minimum supported version to above that

[thekid]

• Use gethostname() function.

See xp-framework/xp-framework@57649d1

[thekid]

• Simplify enum declarations - Simplify enum declarations xp-framework#229

See xp-framework/xp-framework@e9aca5a

[thekid]

• Replace dirname(__FILE__) with __DIR__ constant

See xp-framework/xp-framework@6ec0455

[thekid]

Version checks:

• Remove check for PHP versions < 5.2.1 which only have these memory functions if compiled with --enable-memory-limit (lang.Runtime)
• Remove check for behaviour change in OpenSSL, PHP < 5.2.2 (security.cert.X509Certificate)
• Remove workaround for declaring class bug in PHP < 5.2.10 (lang.XPClass)
• Be able to rely on \v and \f escape sequences, PHP >= 5.2.6 (text.regex.CharacterClass).
• Be able rely on T_NAMESPACE being defined, PHP < 5.3 (text.doclet.RootDoc)

See xp-framework/xp-framework@27a27e0, xp-framework/xp-framework@0e8b6fe, xp-framework/xp-framework@7b0c613, xp-framework/xp-framework@0ba6823 and xp-framework/xp-framework@9aaeee6

🪲

[thekid]

• Remove named pipes workaround

See xp-framework/xp-framework@43a3938