README

Simple Collection class allowing storage of specific data, based on PHP's ArrayObject.

Installation

You can install this class via composer:

composer require yoshi2889/collections

Usage

To use a Collection, create a new instance:

$validationClosure = function ($value)
{
    return is_string($value);
};

$initialItems = ['This is a test value!', 'This is another test value!'];

$collection = new \Yoshi2889\Collections\Collection($validationClosure, $initialItems);

Note that the closure passed as the first parameter to the Collection constructur MUST return a boolean value. This function is used to validate any added data types. A returned value of true means the given value may be added to the collection.

The second parameter can contain any initial values which should be in the collection. These items will also be validated.

Validating

Data is validated using a Closure instance, or a callback. The given closure must support exactly 1 untyped(!) parameter and return a boolean value. Values for which the closure returns false will be denied with an \InvalidArgumentException.

Please note that only the values are validated, while keys are not.

Validation can be manually performed on values using the ->validateType($value) and ->validateArray(array $array) methods, which check a single value and an array of values respectively.

->validateType($value) will return boolean true if the value passes validation, and false if it does not.

->validateArray(array $array) will return boolean true if all the values pass validation, and false if one or more do not.

Manipulation

A Collection instance may be treated like a generic array. This means you can manipulate it like the following example:

$validationClosure = function ($value)
{
    return is_string($value);
};

$collection = new \Yoshi2889\Collections\Collection($validationClosure);

$collection['foo'] = 'bar';

Please note that any data entered this way will still be validated and may still throw an \InvalidArgumentException.

Furthermore, to remove data from the Collection you may use the ->offsetUnset($index) and ->removeAll($value) methods.

->offsetUnset($index) will remove the value located at key $index, which works similarly to using unset($collection['key']).

->removeAll($value) will remove every value which is equal to $value from the collection. Because values may exist multiple times in the same Collection, it is not possible to reliably remove only a single value from the collection using a value; consider removing by key instead. If you wish to preserve the original values while creating a new instance without certain values, please refer to Filtering below.

Filtering

A Collection can be filtered using the ->filter(\Closure $condition) method. The given closure MUST return a boolean value.

The condition closure is called for every element in the collection. Any elements for which the closure returns true will be kept and put in a new Collection instance, which will be returned. For example, to filter out all elements which are NOT foo:

$validationClosure = function ($value)
{
    return is_string($value);
};

$initialItems = ['foo', 'bar', 'baz', 'foo', 'bar', 'baz'];

$collection = new \Yoshi2889\Collections\Collection($validationClosure, $initialItems);

$filterClosure = function ($value)
{
    return $value != 'foo';
};

// Will contain: ['bar', 'baz', 'bar', 'baz']
$newCollection = $collection->filter($filterClosure);

Events

A Collection will emit a changed event if data gets added to or removed from it. No arguments are passed. This functionality is borrowed from Événement by igorw.

You can subscribe to the event using the ->on($event, callable $listener) method, like so:

$collection->on('changed', function ()
{
    echo 'The collection changed!';
});

Validation Closures

You can find a lot of closures and utilities which can be used by a Collection in the separate validation-closures project.

License

This code is released under the MIT License. Please see LICENSE to read it.

yoshi2889 / collections

Maintainers

Details