comparison vendor/nikic/php-parser/doc/component/AST_builders.markdown @ 13:5fb285c0d0e3

Update Drupal core to 8.4.7 via Composer. Security update; I *think* we've been lucky to get away with this so far, as we don't support self-registration which seems to be used by the so-called "drupalgeddon 2" attack that 8.4.5 was vulnerable to.
author Chris Cannam
date Mon, 23 Apr 2018 09:33:26 +0100
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1 AST builders
2 ============
3
4 When PHP-Parser is used to generate (or modify) code by first creating an Abstract Syntax Tree and
5 then using the [pretty printer](Pretty_printing.markdown) to convert it to PHP code, it can often
6 be tedious to manually construct AST nodes. The project provides a number of utilities to simplify
7 the construction of common AST nodes.
8
9 Fluent builders
10 ---------------
11
12 The library comes with a number of builders, which allow creating node trees using a fluent
13 interface. Builders are created using the `BuilderFactory` and the final constructed node is
14 accessed through `getNode()`. Fluent builders are available for
15 the following syntactic elements:
16
17 * namespaces and use statements
18 * classes, interfaces and traits
19 * methods, functions and parameters
20 * properties
21
22 Here is an example:
23
24 ```php
25 use PhpParser\BuilderFactory;
26 use PhpParser\PrettyPrinter;
27 use PhpParser\Node;
28
29 $factory = new BuilderFactory;
30 $node = $factory->namespace('Name\Space')
31 ->addStmt($factory->use('Some\Other\Thingy')->as('SomeOtherClass'))
32 ->addStmt($factory->class('SomeOtherClass')
33 ->extend('SomeClass')
34 ->implement('A\Few', '\Interfaces')
35 ->makeAbstract() // ->makeFinal()
36
37 ->addStmt($factory->method('someMethod')
38 ->makePublic()
39 ->makeAbstract() // ->makeFinal()
40 ->setReturnType('bool')
41 ->addParam($factory->param('someParam')->setTypeHint('SomeClass'))
42 ->setDocComment('/**
43 * This method does something.
44 *
45 * @param SomeClass And takes a parameter
46 */')
47 )
48
49 ->addStmt($factory->method('anotherMethod')
50 ->makeProtected() // ->makePublic() [default], ->makePrivate()
51 ->addParam($factory->param('someParam')->setDefault('test'))
52 // it is possible to add manually created nodes
53 ->addStmt(new Node\Expr\Print_(new Node\Expr\Variable('someParam')))
54 )
55
56 // properties will be correctly reordered above the methods
57 ->addStmt($factory->property('someProperty')->makeProtected())
58 ->addStmt($factory->property('anotherProperty')->makePrivate()->setDefault(array(1, 2, 3)))
59 )
60
61 ->getNode()
62 ;
63
64 $stmts = array($node);
65 $prettyPrinter = new PrettyPrinter\Standard();
66 echo $prettyPrinter->prettyPrintFile($stmts);
67 ```
68
69 This will produce the following output with the standard pretty printer:
70
71 ```php
72 <?php
73
74 namespace Name\Space;
75
76 use Some\Other\Thingy as SomeClass;
77 abstract class SomeOtherClass extends SomeClass implements A\Few, \Interfaces
78 {
79 protected $someProperty;
80 private $anotherProperty = array(1, 2, 3);
81 /**
82 * This method does something.
83 *
84 * @param SomeClass And takes a parameter
85 */
86 public abstract function someMethod(SomeClass $someParam) : bool;
87 protected function anotherMethod($someParam = 'test')
88 {
89 print $someParam;
90 }
91 }
92 ```
93
94 Additional helper methods
95 -------------------------
96
97 The `BuilderFactory` also provides a number of additional helper methods, which directly return
98 nodes. The following methods are currently available:
99
100 * `val($value)`: Creates an AST node for a literal value like `42` or `[1, 2, 3]`.
101 * `args(array $args)`: Creates an array of function/method arguments, including the required `Arg`
102 wrappers. Also converts literals to AST nodes.
103 * `funcCall($name, array $args = [])`: Create a function call node. Converts `$name` to a `Name`
104 node and normalizes arguments.
105 * `methodCall(Expr $var, $name, array $args = [])`: Create a method call node. Converts `$name` to
106 an `Identifier` node and normalizes arguments.
107 * `staticCall($class, $name, array $args = [])`: Create a static method call node. Converts
108 `$class` to a `Name` node, `$name` to an `Identifier` node and normalizes arguments.
109 * `new($class, array $args = [])`: Create a "new" (object creation) node. Converts `$class` to a
110 `Name` node.
111 * `constFetch($name)`: Create a constant fetch node. Converts `$name` to a `Name` node.
112 * `classConstFetch($class, $name)`: Create a class constant fetch node. Converts `$class` to a
113 `Name` node and `$name` to an `Identifier` node.
114 * `concat(...$exprs)`: Create a tree of `BinaryOp\Concat` nodes for the given expressions.
115
116 These methods may be expanded on an as-needed basis. Please open an issue or PR if a common
117 operation is missing.