11828 Fix issue with swatch colour block not showing in admin panel once colour selected (PHP7.1.x issue).

[chris-pook]

Description

Using PHP7.1.x the swatch colour block preview in the admin panel attribute will not show the actual colour as the inline style is set to style"b". This is due to PHP no longer allowing strings to be manipulated as arrays.

Fixed Issues (if relevant)

1. Visual Swatches not showing swatch color in admin #11828: Visual Swatches not showing swatch color in admin

Manual testing scenarios

Preconditions
Magento CE 2.2
PHP 7.1.0
Steps to reproduce
Inside admin, go to Stores->Product and click on an attribute that contains visual swatches.
Expected result
Visual Swatches that have a color assigned should show that color in the swatch box.
Actual result
Although the color swatch values are being saved, the visual representation of the color in the box is colorless.

Contribution checklist

• [ x] Pull request has a meaningful description of its purpose
• [ x] All commits are accompanied by meaningful commit messages
• [ x] All new or changed code is covered with unit/integration tests (if applicable)
• [ x] All automated tests passed successfully (all builds on Travis CI are green)

[ihor-sviziev]

@chris-pook could you explain what it was returning in php 7.0? There is string to array conversion, so probably we were getting some unexpected result

[chris-pook]

Hi @ihor-sviziev on php7.0 an array is returned containing the inline style strings as set by the function. The problem is that using php7.1 the strings are truncated due to the odd way they are produced using array notation on $newSwatch which is defined as a string.

To see the issue introduced in php7.1 you can run the following code:

<?php
$str = '';
$str[3] = 'background';
var_dump($str[3]);

With php7.0 this will produce:

string(10) "background"

With php7.1 this will output:

string(1) "b"

[orlangur]

It can still be null. Could you also squash changes into single commit and force push?

[chris-pook]

@orlangur updated docblock and squashed commits down to 1 (apologies for multiple updates, messed up a local merge).