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#[php_impl] Attribute

You can export an entire impl block to PHP. This exports all methods as well as constants to PHP on the class that it is implemented on. This requires the #[php_class] macro to already be used on the underlying struct. Trait implementations cannot be exported to PHP. Only one impl block can be exported per class.

If you do not want a function exported to PHP, you should place it in a separate impl block.

If you want to use async Rust, use #[php_async_impl], instead: see here » for more info.

Options

By default all constants are renamed to UPPER_CASE and all methods are renamed to camelCase. This can be changed by passing the change_method_case and change_constant_case as #[php] attributes on the impl block. The options are:

  • #[php(change_method_case = "snake_case")] - Renames the method to snake case.
  • #[php(change_constant_case = "snake_case")] - Renames the constant to snake case.

See the name and change_case section for a list of all available cases.

Methods

Methods basically follow the same rules as functions, so read about the [php_function] macro first. The primary difference between functions and methods is they are bounded by their class object.

Class methods can take a &self or &mut self parameter. They cannot take a consuming self parameter. Static methods can omit this self parameter.

To access the underlying Zend object, you can take a reference to a ZendClassObject<T> in place of the self parameter, where the parameter must be named self_. This can also be used to return a reference to $this.

The rest of the options are passed as separate attributes:

  • #[php(defaults(i = 5, b = "hello"))] - Sets the default value for parameter(s).
  • #[php(optional = i)] - Sets the first optional parameter. Note that this also sets the remaining parameters as optional, so all optional parameters must be a variant of Option<T>.
  • #[php(vis = "public")], #[php(vis = "protected")] and #[php(vis = "private")] - Sets the visibility of the method.
  • #[php(name = "method_name")] - Renames the PHP method to a different identifier, without renaming the Rust method name.
  • #[php(final)] - Makes the method final (cannot be overridden in subclasses).
  • #[php(abstract)] - Makes the method abstract (must be implemented by subclasses). Can only be used in abstract classes.

The #[php(defaults)] and #[php(optional)] attributes operate the same as the equivalent function attribute parameters.

Static Methods

Methods that do not take a &self or &mut self parameter are automatically exported as static methods. These can be called on the class itself without creating an instance.

#[php_impl]
impl MyClass {
    // Static method - no self parameter
    pub fn create_default() -> Self {
        Self { /* ... */ }
    }

    // Instance method - takes &self
    pub fn get_value(&self) -> i32 {
        self.value
    }
}

From PHP:

$obj = MyClass::createDefault(); // Static call
$val = $obj->getValue();         // Instance call

Final Methods

Methods marked with #[php(final)] cannot be overridden in subclasses. This is useful when you want to prevent modification of critical functionality.

use ext_php_rs::prelude::*;

#[php_class]
pub struct SecureClass;

#[php_impl]
impl SecureClass {
    #[php(final)]
    pub fn secure_method(&self) -> &str {
        "This cannot be overridden"
    }

    // Final static methods are also supported
    #[php(final)]
    pub fn secure_static() -> i32 {
        42
    }
}

Abstract Methods

Methods marked with #[php(abstract)] must be implemented by subclasses. Abstract methods can only be defined in abstract classes (classes with ClassFlags::Abstract).

use ext_php_rs::prelude::*;
use ext_php_rs::flags::ClassFlags;

#[php_class]
#[php(flags = ClassFlags::Abstract)]
pub struct AbstractShape;

#[php_impl]
impl AbstractShape {
    // Protected constructor for subclasses
    #[php(vis = "protected")]
    pub fn __construct() -> Self {
        Self
    }

    // Abstract method - subclasses must implement this.
    // The body is never called; use unimplemented!() as a placeholder.
    #[php(abstract)]
    pub fn area(&self) -> f64 {
        unimplemented!()
    }

    // Concrete method in abstract class
    pub fn describe(&self) -> String {
        format!("A shape with area {}", self.area())
    }
}

Note: Abstract method bodies are never called - they exist only because Rust syntax requires a body for methods in impl blocks. Use unimplemented!() as a clear placeholder.

Note: If you try to use #[php(abstract)] on a method in a non-abstract class, you will get a compile-time error.

Note: PHP does not support abstract static methods. If you need static behavior that can be customized by subclasses, use a regular instance method or the late static binding pattern in PHP.

Constructors

By default, if a class does not have a constructor, it is not constructable from PHP. It can only be returned from a Rust function to PHP.

Constructors are Rust methods which can take any amount of parameters and returns either Self or Result<Self, E>, where E: Into<PhpException>. When the error variant of Result is encountered, it is thrown as an exception and the class is not constructed.

Constructors are designated by either naming the method __construct or by annotating a method with the #[php(constructor)] attribute. Note that when using the attribute, the function is not exported to PHP like a regular method.

Constructors cannot use the visibility or rename attributes listed above.

Constants

Constants are defined as regular Rust impl constants. Any type that implements IntoZval can be used as a constant. Constant visibility is not supported at the moment, and therefore no attributes are valid on constants.

Property getters and setters

You can add properties to classes which use Rust functions as getters and/or setters. This is done with the #[php(getter)] and #[php(setter)] attributes. By default, the get_ or set_ prefix is trimmed from the start of the function name, and the remainder is used as the property name.

If you want to use a different name for the property, you can pass a name or change_case option to the #[php] attribute which will change the property name.

Properties do not necessarily have to have both a getter and a setter, if the property is immutable the setter can be omitted, and vice versa for getters.

The #[php(getter)] and #[php(setter)] attributes are mutually exclusive on methods. Properties cannot have multiple getters or setters, and the property name cannot conflict with field properties defined on the struct.

As the same as field properties, method property types must implement both IntoZval and FromZval.

Overriding field properties with getters/setters

If you have a field property defined with #[php(prop)] on your struct, you can override its access by defining a getter or setter method with the same property name. The method-based property will take precedence:

use ext_php_rs::prelude::*;

#[php_class]
pub struct Book {
    #[php(prop)]
    pub title: String,  // Direct field access
}

#[php_impl]
impl Book {
    pub fn __construct(title: String) -> Self {
        Self { title }
    }

    // This getter overrides $book->title access
    #[php(getter)]
    pub fn get_title(&self) -> String {
        format!("Title: {}", self.title)
    }
}

In PHP, accessing $book->title will now call the get_title() method instead of directly accessing the field:

$book = new Book("The Rust Book");
echo $book->title; // Output: "Title: The Rust Book"

This is useful when you need to add validation, transformation, or side effects to property access while still having the convenience of a public field in Rust.

Example

Continuing on from our Human example in the structs section, we will define a constructor, as well as getters for the properties. We will also define a constant for the maximum age of a Human.

#![cfg_attr(windows, feature(abi_vectorcall))]
extern crate ext_php_rs;
use ext_php_rs::{prelude::*, types::ZendClassObject};

#[php_class]
#[derive(Debug, Default)]
pub struct Human {
    name: String,
    age: i32,
    #[php(prop)]
    address: String,
}

#[php_impl]
impl Human {
    const MAX_AGE: i32 = 100;

    // No `#[constructor]` attribute required here - the name is `__construct`.
    pub fn __construct(name: String, age: i32) -> Self {
        Self {
            name,
            age,
            address: String::new()
        }
    }

    #[php(getter)]
    pub fn get_name(&self) -> String {
        self.name.to_string()
    }

    #[php(setter)]
    pub fn set_name(&mut self, name: String) {
        self.name = name;
    }

    #[php(getter)]
    pub fn get_age(&self) -> i32 {
        self.age
    }

    pub fn introduce(&self) {
        println!("My name is {} and I am {} years old. I live at {}.", self.name, self.age, self.address);
    }

    pub fn get_raw_obj(self_: &mut ZendClassObject<Human>) -> &mut ZendClassObject<Human> {
        dbg!(self_)
    }

    pub fn get_max_age() -> i32 {
        Self::MAX_AGE
    }
}
#[php_module]
pub fn get_module(module: ModuleBuilder) -> ModuleBuilder {
    module.class::<Human>()
}
fn main() {}

Using our newly created class in PHP:

<?php

$me = new Human('David', 20);

$me->introduce(); // My name is David and I am 20 years old.
var_dump(Human::get_max_age()); // int(100)
var_dump(Human::MAX_AGE); // int(100)