serenata/name-qualification-utilities

Provides utilities for dealing with PHP name qualifications, such as resolving and localizing names.

0.6.0 2020-10-25 20:45 UTC

This package is auto-updated.

Last update: 2022-01-25 22:48:05 UTC


README

Provides various utilities related to name qualification in PHP:

  • Determine what namespace and imports are active at a specific location in a file
  • Resolve names to their fully qualified name based on use statements and namespaces
  • Localize names from a fully qualified name back to a local name based on use statements and namespaces

This project falls under the Serenata umbrella.

Installation

composer require "serenata/name-qualification-utilities"

Usage

<?php

use Serenata\Common\Position;
use Serenata\Common\FilePosition;

use Serenata\NameQualificationUtilities;

// NOTE: Implement a suitable provider in your code.
$fileNamespaceProvider = new class implements NameQualificationUtilities\FileNamespaceProviderInterface {
    public function provide(string $file): array
    {
        return $arrayOfNamespaceObjectsWithImportsAttached;
    }
};

$positionalNamespaceDeterminer = new NameQualificationUtilities\PositionalNamespaceDeterminer($fileNamespaceProvider);

$factory = new NameQualificationUtilities\PositionalNameResolverFactory($positionalNamespaceDeterminer);

// Create a name resolver that can resolve names using the imports and namespace that apply at the specified position.
$position = new Position($someLineNumber, $someCharacterIndexOnLine);
$filePosition = new FilePosition('MyPhpFile.php', $position);

$nameResolver = $factory->create($filePosition);

$result = $nameResolver->resolve('A', NameQualificationUtilities\NameKind::CLASSLIKE);

// $result will now contain the FQCN of the class, e.g. '\A', '\SomeNamespace\A', ...

Not a PHP parser

Actual parsing of code to find available imports and namespaces is not provided, but you can use a tool such as php-parser for this. Instead, the available imports and namespaces have to be provided by the user of this library by implementing the interface FileNamespaceProviderInterface.

What is the "kind" parameter all about?

It is necessary because PHP supports use statements or imports with the same name, as long as their "kind" is different. In other words, you can import a constant with the same name as a class:

<?php

use A\B;
use function A\B;
use const A\B;

What is the difference between NamespaceNameResolver and StructureAwareNameResolver?

Some constant and function names can be ambiguous, for example:

<?php

namespace A;

$a = SOME_CONSTANT;

SOME_CONSTANT can refer to \A\SOME_CONSTANT or \SOME_CONSTANT, PHP determines which one to use at runtime:

  1. Resolve to \A\SOME_CONSTANT if it exists
  2. Resolve to \SOME_CONSTANT if it exists
  3. Resolve to \A\SOME_CONSTANT again and fail because neither exist

NamespaceNameResolver does not know how to handle this situation and will bail out with an exception that the name is ambiguous.

StructureAwareNameResolver will request additional information - from a provider you must inject into it - to determine which structures actually exist in order to successfully resolve the name.

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