Why You Need a PHP Backwards Compatibility Library Before You Upgrade to a Newer PHP Version - PHP Backwards Compatibility Library package blog

In this article you will learn about:

What is the PHP Backwards Compatibility Library (phpBCL)

How can I Download or Install the PHP Backwards Compatibility Library Using the PHP Composer Tool

Why It Is Necessary a PHP Backwards Compatibility Library

Each new version of PHP incorporates new features and functions, some of which are necessary because they fix programming logic. Still, others are included or removed to make programmers' lives more difficult.

This active activity has made PHP developers a target of this logic. A big part of the daily grind is finding ways to make the project we're building compatible with most versions of PHP.

This activity has made PHP developers a target of this logic. A big part of the daily grind is finding ways to make the project we're building compatible with most versions of PHP.

Now, we have reached the point in each sub-version of PHP to have at least one deprecated code and one declaration that this code will be deleted in some future version.

Common sense would suggest that it would be preferable to move code that the PHP core developers deem to be deprecated into a new .dll (.so) file that would be available to anyone who wanted to use the deprecated code.

Another common sense would say, "If you take something away, you must give something." They could provide each deprecated code with a compatible PHP code with the name of the deprecated functions. But even that is not possible.

This painstaking task has been left entirely in the hands of PHP users.

What is the PHP Backwards Compatibility Library (phpBCL)

One effort to avoid this painstaking task of making your project PHP code work with newer PHP versions is the phpBCL library (PHP Backwards Compatibility Library).

This package comes to correct, in part, the "deprecated stupidity," as I call it.

First of all, the phpBCL library is a public-use adapted part (powerful and dynamic though) of the full library that exists in the Ascoos Cms kernel and is intended to adapt the features of the new versions, to the code written on the based on older versions.

E.g., in PHP 8.3, a new function, json_validate, has been added, which aims to check the validity of a JSON to a given string.

In the past, each programmer made their function. But with version 8.3 ready for use by the end of 2023, we won't need to write additional code.

In the phpBCL library, there is already this function with functionality exactly like the upcoming built-in function.

So we can now change the code using the phpBCL library function, and when 8.3 is ready, phpBCL itself knows that it should no longer load its contents that are the same as those built into this version.

But for older versions, it will still load the code that emulates features with version 8.3.

But the same happens for features of older versions where for each older version, phpBCL loads the features of all newer versions.

E.g., if you run a script in PHP 5.6, phpBCL will load as many features as it has implemented for versions 7.0 - 7.4, 8.0 through 8.3. So even if a script is written for an old version, it is possible to run many of the additions made in newer versions.

The phpBCL package can be downloaded from the package page by clicking on the Download tab.

If you use the PHP Composer tool, you can also install this package automatically and use it in your projects that also use PHP Composer.

You just need to add a few lines of JSON data to your project  composer.json file. The lines that you need to add may be found in the phpBCL package page Download tab and then click in the Install with Composer button.