makeInstance adressing issue

README

Demonstrate the usage of makeInstance and/or php namespaces adressing background

demo.php

<?php

namespace test {
    class foo {

    }

    // fixed
    $testFoo = new foo();
    //$anotherFoo = test/foo(); // fatal
    $testYetAnotherFoo = new \test\foo();

    // dynamic
    // $foo = 'foo'; // fatal
    $fooFullyQualifiedName = '\\test\\foo';
    $fooQualifiedName = 'test\\foo';

    $testFooFullyQualified = new $fooFullyQualifiedName;
    var_dump(get_class($testFooFullyQualified));

    $testFooQualified = new $fooQualifiedName;
    var_dump(get_class($testFooQualified));

}

namespace {
    // fixed
    // $testFoo = new foo();  // fatal
    $anotherFoo = new test\foo();
    $testYetAnotherFoo = new \test\foo();

    echo "" . PHP_EOL;

    // dynamic
    $fooFullyQualifiedName = '\\test\\foo';
    $fooQualifiedName = 'test\\foo';

    $testFooFullyQualified = new $fooFullyQualifiedName;
    var_dump(get_class($testFooFullyQualified));

    $testFooQualified = new $fooQualifiedName;
    var_dump(get_class($testFooQualified));

    echo "" . PHP_EOL;
    echo "Lessons learned:" . PHP_EOL;
    echo "In *global* scope you can use 1) full qualified name *or* 2) qualified names" . PHP_EOL;
    echo "php internally always represents the classname only *qualified*" . PHP_EOL;
    echo "which is fine because from php perspective this is *global* namespace scope" . PHP_EOL;
    echo "" . PHP_EOL;

}

dummy.php

/*
* in plain PHP
*/
// qualified relative (subnamespace) class instantiation
$fileUtility = new File\BasicFileUtility();

// fully qualified (absolute)
$fileUtility = new \TYPO3\CMS\Core\Utility\File\BasicFileUtility();

/* 
* TYPO3 makeInstance or any other plain dynamic language context (variables as class names etc. pp')
*/
$fileUtility = GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\Utility\\File\\BasicFileUtility');

// Thx to @helhum for clearification/explanation
// we are using a dynamic language feature (classname as variable), thus it will be always interpreted in *global* namespace.
// So both fully qualified(leading slash) as well as qualified names do work from php perspective

// As internally the class name is stored qualified (without leading slash) it is easier to force to supply names qualified only.

btw, Updated the gist and put my essence "lessons learned" into demo.php.