Issue-863: PHP Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated

[anubisthejackle]

Note: To minimize the impact on the rest of the Fieldmanager fields, this change is localized to the TextArea field, since that appears to be where the issue is occurring.

Fixes Issue

PHP Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated

Description of Change

To address the issue of PHP deprecation errors when a default_value field is not set and defaults to null, we have modified the logic in the printing of fields within the WP admin area. Specifically, in scenarios where a default value is not set, which leads to a null return value, a ternary operation or a direct assignment now ensures that esc_textarea receives an empty string instead of null. This change prevents htmlspecialchars() from throwing a deprecation notice due to receiving a null value.

The modification was implemented in the handling of default values within the Fieldmanager_TextArea class to circumvent the deprecation notice. It's crucial to emphasize that the default behavior for handling default values remains unaltered to prevent unintended side effects in other areas of the application.

Use Case Affected

This change impacts any site using fields that extend Fieldmanager_TextArea, specifically in scenarios where the default_value is not explicitly set. The new default value will be an empty string and not null as it was previously.

Comments/Suggestions

• @renatonascalves has played a crucial role in suggesting the approach of defaulting to an empty string within the Fieldmanager_Textarea class to address this deprecation issue.

Acceptance Criteria

• With no default value set, resulting in a null return value, esc_textarea will now receive an empty string instead of null.
• The approach to handling default values should not be fundamentally altered to avoid unintended consequences in other parts of the application.

[mogmarsh]

👍