https://github.com/liamja/defer

PHP library to postpone the calling of a function or callable.
https://github.com/liamja/defer

composer-library composer-package php php5 php53 php54 php55 php56

Last synced: about 2 months ago
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PHP library to postpone the calling of a function or callable.

• Host: GitHub
• URL: https://github.com/liamja/defer
• Owner: liamja
• Created: 2018-02-18T17:28:06.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-02-18T17:39:09.000Z (almost 7 years ago)
• Last Synced: 2024-10-13T12:20:14.064Z (3 months ago)
• Topics: composer-library, composer-package, php, php5, php53, php54, php55, php56
• Language: PHP
• Homepage:
• Size: 6.84 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Defer

Postpone the calling of a function or callable.

## Why?

From _Go by Example_:

> Defer is used to ensure that a function call is performed later in a program’s execution, usually for purposes of cleanup. 

> `defer` is often used where e.g. `ensure` and `finally` would be used in other languages.

Common use cases are:

* Cleaning up temporary files.

* Closing network connections.

* Closing database connections.

Comparing `defer` to `finally`, this implementation of `defer` will allow us to have better control over when our

deferred functions are called; we can decide when to start stacking deferred functions, and where to finally call them.

## Examples

### Usage

```php

// Create an instance of Defer.

// When $defer falls out of scope, the deferred callables will be called in reverse order.

$defer = new Defer;

// Push your deferred tasks to the $defer object.

$defer->push(function () {

    echo "I'm echoed last!";

});

// As a convenience, you can also call $defer as a function

$defer(function () {

    echo "I'm echoed second!";

});

echo "I'm called first!";

```

### Closing Resources

Defer can be used for ensuring the closing of open files:

```php

$fp = fopen('/tmp/file', 'w');

$defer(function () use ($fp) {

   fclose($fp);

});

fwrite($fp, 'Some temporary data.');

```