README

Micro catalog PHP template class, useful to create value objects based on a known small catalog.

Several times I have the need for a catalog, by example, when receiving a result code and correlate to specific related values. This library helps me to resolve this common problem, and it may help you too.

Installation

Use composer, install using:

composer require eclipxe/micro-catalog

Usage

MicroCatalog is a template class, so you need to extend it to use it. Strictly speaking, you only need to implement two abstract methods: getEntriesArray(): array and getEntryValueOnUndefined(): mixed.

The sugar lives on is<Type>(): bool and get<Property>(): bool, with the special case of isUndefined(): bool. The is<Type>() methods allow to distinct a type by its index. The get<Property>() methods allow to get a string key from the value array when it has content.

See the following examples:

• ResultCodes Common usage with value as scalar, allows undefined properties.
• ComplexArray Common usage with value as array, get property, allows undefined properties.
• ComplexObject Common usage with value as object, get property, disable undefined properties.

MicroCatalog example

<?php

declare(strict_types=1);

use Eclipxe\MicroCatalog\MicroCatalog;

/**
 * ResultCodes is an example class to show the basic usage
 *
 * @method bool isOk()
 * @method bool isWarning()
 * @method bool isError()
 */
final class ResultCodes extends MicroCatalog
{
    public static function getEntriesArray(): array
    {
        return [
            0 => 'Ok',
            1 => 'Warning',
            2 => 'Error',
        ];
    }

    public function getEntryValueOnUndefined(): string
    {
        return '#N/A';
    }

    public function getEntryId(): string
    {
        return strval($this->getEntryValue());
    }
}

$warning = new ResultCodes(1);
var_dump($warning->isWarning());        // bool(true)
var_dump($warning->getEntryIndex());    // int(1)
var_dump($warning->getEntryValue());    // string(7) "Warning"
var_dump($warning->getEntryId());       // string(7) "Warning" (method was overriden)
var_dump($warning->isUndefined());      // bool(false)

$other = new ResultCodes(99);
var_dump($other->isUndefined());        // bool(true)
var_dump($other->getEntryIndex());      // int(99)
var_dump($other->getEntryValue());      // string(4) "#N/A"

Undefined entry

When creating an instance of MicroCatalog, when the key isn't found in the list of known values it will use the value from getValueOnUndefined().

If you don't want to allow unknown instances you can override and throw an exception on getValueOnUndefined().

Check if instance is of certain entry

Use the methods is<name>() to compare to specific value.

It will work by default when the indexes are strings, in example: isFoo() will evaluate if the current index is foo (with the first character as lower case).

You can redefine whits behavior by overriding the getEntryId(): string function. So isFoo() will compare foo with the returned value of getEntryId(): string.

You have to define these methods in your docblock to let your IDE or code analyzer detect what you are doing.

Get a magic property

If your known values array constains an array with string keys or a standard object with public variables then getSomething() will return what is defined on something key/property.

Even when PHP supports method with different case, this class use exact case, so getSomething() is different from getSomeThing(). The only transformation made to locate the key/property is to lower first char, then getSomething() will look up for something into local value. Anyhow, you can override the method getEntryValueWithKey(string $key): mixed to perform other transformation on key/property name.

Extending

I recommend you to declare your MicroCatalog classes as final to disable extension.

When creating a MicroCatalog extending from other, the parent MicroCatalog have priority on indices and values. You cannot override indices or values of previous classes.

Exceptions

Exceptions thrown from this package implements the empty interface Eclipxe\MicroCatalog\Exceptions\MicroCatalogException.

Creational patterns

You can write other creational patterns, the implemented constructor uses the value as index entry. If you want to create an entry based on some value or other type of evaluation I don't recommend to you to override the constructor, instead you can use static method calls.

PHP Support

This library is compatible with at least the oldest PHP Supported Version with active support. Please, try to use PHP full potential.

We adhere to Semantic Versioning. We will not introduce any compatibility backwards change on major versions.

Internal classes (using @internal annotation) are not part of this agreement as they must only exist inside this project. Do not use them in your project.

Contributing

Contributions are welcome! Please read CONTRIBUTING for details and don't forget to take a look in TODO and CHANGELOG files.

Copyright and License

The eclipxe/micro-catalog library is copyright © Carlos C Soto and licensed for use under the MIT License (MIT). Please see LICENSE for more information.