Introduction

What is considered as a conditional code ?

Each time you found following functions in source code :

• extension_loaded
• function_exists
• method_exists
• class_exists
• interface_exists
• trait_exists
• defined

Note for developers, this is the Bartlett\CompatInfo\Sniffs\Expressions\ConditionalCodeSniff sniff that handle it !

This feature was improve since previous versions until 5.4, but has some limits you should know.

• if we detect one of these previous function, we do not compute php.min, php.max, ext.* version elements to global or parent results.

That means, with this code :

<?php
Class C
{
    function encode()
    {
        if (!function_exists('json_encode')) {
            function json_encode($value, $options = 0, $depth = 512) {
                // ... do something
            }
        }
    }
}

When we run analyser, we got this output :

Data Source Analysed

Directories                                          1
Files                                                1
Errors                                               0


Extensions Analysis

    Extension REF  EXT min/Max PHP min/Max
    Core      Core 4.0.0       4.0.0
 C  json      json 5.2.0       5.2.0
    Total [2]                  4.0.0

Namespaces Analysis

    Namespace REF  EXT min/Max PHP min/Max
              Core             4.0.0
    Total [1]                  4.0.0

No interface found

No trait found

Classes Analysis

    Class     REF  EXT min/Max PHP min/Max
    C         user             4.0.0
    Total [1]                  4.0.0

No generator found

Functions Analysis

    Function             REF  EXT min/Max PHP min/Max
    C\encode\json_encode user             4.0.0
    function_exists      Core 4.0.0       4.0.0
 C  json_encode          json 5.2.0       5.2.0
    Total [3]                             4.0.0

No constant found

Conditions Analysis

    Condition                    REF  EXT min/Max PHP min/Max
    function_exists(json_encode) json 5.2.0       5.2.0
    Total [1]                                     5.2.0

Requires PHP 4.0.0 (min)

Each data with a C in front of line tell us that the code is conditional.

json_encode native function that come with PHP 7.2 is only used for PHP 7.2 or greater and the user function C\encode\json_encode is used for PHP versions less or equal 7.1.*

This is a very simple example. There are much more difficult situation that CompatInfo can handle, and some that we cannot !