Changeset 56354

Timestamp:

08/03/2023 06:11:36 PM (3 years ago)

Author:

hellofromTonya

Message:

Code Modernization: Deprecate dynamic properties in WP_Text_Diff_Renderer_Table magic methods.

The unknown use of unknown dynamic property within the WP_Text_Diff_Renderer_Table property magic methods is now deprecated. A descriptive deprecation notice is provided to alert developers to declare the property on the child class extending WP_Text_Diff_Renderer_Table.

Changes in this commit:

• Adds a deprecation notice to the __get(), __set(), __isset(), __unset() magic methods, i.e. to alert and inform developers when attempting to get/set/isset/unset a dynamic property.
• Fixes __get() to explicitly returns null when attempting to get a dynamic property.
• Fixes __set() by removing the value return after setting a declared property, as (a) unnecessary and (b) __set() should return void ​per the PHP handbook.
• Fixes __isset() to return false if not in the $compat_fields, as isset() and __isset() should always return bool:
  • ​`__isset()` in the PHP manual
  • ​`isset()` in the PHP manual
• Adds a test class with happy and unhappy paths for these changes.

For backward compatibility, no changes are made to the internal declared properties listed in $compat_fields and accessed through the magic methods.

For example:
A child class uses a property named $data that is not declared as a property on the child class. When getting its value, e.g. $user_query->data, the WP_Text_Diff_Renderer_Table::__get() magic method is invoked, the following deprecation notice thrown, and null returned:

The property data is not declared. Setting a dynamic property is deprecated since version 6.4.0! Instead, declare the property on the class.

Why not remove the magic methods, remove the $compat_fields property, and restore the properties public?

tl;dr Backward compatibility.

If a plugin adds a property to $compat_fields array, then sites using that plugin would experience (a) an Undefined property Warning (PHP 8) | Notice (PHP 7) and (b) a possible change in behavior.

Why not limit the deprecation for PHP versions >= 8.2?

tl;dr original design intent and inform

The magic methods and $compat_fields property were added for one purpose: to continue providing external access to internal properties declared on WP_Text_Diff_Renderer_Table. They were not intended to be used for dynamic properties.

Deprecating that unintended usage both alerts developers a change is needed in their child class and informs them what to change.

References:

• Dynamic (non-explicitly declared) properties are deprecated as of PHP 8.2 and are expected to become a fatal error in PHP 9.0.
• A ​live open public working session where these changes were discussed and agreed to.
• ​PHP RFC: Deprecate dynamic properties.

Follow-up to [28525], [31135].

Props antonvlasenko, rajinsharwar, jrf, markjaquith, hellofromTonya, SergeyBiryukov, desrosj, peterwilsoncc, audrasjb, costdev, oglekler, jeffpaul.
Fixes #58898.
See #56034.

Location:

trunk

Files:

• src/wp-includes/class-wp-text-diff-renderer-table.php (modified) (7 diffs)
• tests/phpunit/tests/diff (added)
• tests/phpunit/tests/diff/wpTextDiffRendererTable.php (added)

trunk/src/wp-includes/class-wp-text-diff-renderer-table.php

@@ -512 +512 @@
          *
          * @since 4.0.0
+         * @since 6.4.0 Getting a dynamic property is deprecated.
          *
          * @param string $name Property to get.
-         * @return mixed Property.
+         * @return mixed A declared property's value, else null.
          */
         public function __get( $name ) {
@@ -520 +521 @@
                         return $this->$name;
                 }
+
+                trigger_error(
+                        "The property `{$name}` is not declared. Getting a dynamic property is " .
+                        'deprecated since version 6.4.0! Instead, declare the property on the class.',
+                        E_USER_DEPRECATED
+                );
+                return null;
         }
 
@@ -526 +534 @@
          *
          * @since 4.0.0
+         * @since 6.4.0 Setting a dynamic property is deprecated.
          *
          * @param string $name  Property to check if set.
          * @param mixed  $value Property value.
-         * @return mixed Newly-set property.
          */
         public function __set( $name, $value ) {
                 if ( in_array( $name, $this->compat_fields, true ) ) {
-                        return $this->$name = $value;
-                }
+                        $this->$name = $value;
+                        return;
+                }
+
+                trigger_error(
+                        "The property `{$name}` is not declared. Setting a dynamic property is " .
+                        'deprecated since version 6.4.0! Instead, declare the property on the class.',
+                        E_USER_DEPRECATED
+                );
         }
 
@@ -541 +556 @@
          *
          * @since 4.0.0
+         * @since 6.4.0 Checking a dynamic property is deprecated.
          *
          * @param string $name Property to check if set.
@@ -549 +565 @@
                         return isset( $this->$name );
                 }
+
+                trigger_error(
+                        "The property `{$name}` is not declared. Checking `isset()` on a dynamic property " .
+                        'is deprecated since version 6.4.0! Instead, declare the property on the class.',
+                        E_USER_DEPRECATED
+                );
+                return false;
         }
 
@@ -555 +578 @@
          *
          * @since 4.0.0
+         * @since 6.4.0 Unsetting a dynamic property is deprecated.
          *
          * @param string $name Property to unset.
@@ -561 +585 @@
                 if ( in_array( $name, $this->compat_fields, true ) ) {
                         unset( $this->$name );
-                }
+                        return;
+                }
+
+                trigger_error(
+                        "A property `{$name}` is not declared. Unsetting a dynamic property is " .
+                        'deprecated since version 6.4.0! Instead, declare the property on the class.',
+                        E_USER_DEPRECATED
+                );
         }
 }