AssocArray.php

<?php
	
	abstract class AssocArray {
		
		public $pairs = [];
		
		public $required, $values;
		
		function __construct (array $data = []) {
			
			$this->required = $this->getRequiredPairs ();
			$this->values = $this->getRequiredValues ();
			
			foreach ($this->getPairs () as $key => $value)
				$this->set ($key, $value);
			
			foreach ($data as $key => $value)
				$this->set ($key, $value);
			
		}
		
		function getPairs (): array {
			return [];
		}
		
		function getRequiredPairs (): array {
			return [];
		}
		
		function getRequiredValues (): array {
			return [];
		}
		
		function set ($key, $value) {
			
			if (in_array ($key, array_keys ($this->values)) and !in_array ($value, $this->values[$key]))
				throw new \Exception ($key.' value must be '.implode (', ', $this->values[$key]));
			else
				$this->pairs[$key] = $value;
			
			return $this;
			
		}
		
		function get ($key) {
			
			if (isset ($this->pairs[$key]))
				return $this->pairs[$key];
			else
				return null;
			
		}
		
		function validate (): AssocArray {
			
			if ($missed = $this->diff (array_keys ($this->pairs), $this->required))
				throw new \Exception ('Required keys missed: '.implode (', ', $missed));
			
			return $this;
			
		}
		
		protected function diff (...$arrays) {
			
			$diff = [];
			
			$arr = $arrays[0];
			
			foreach ($arrays as $key => $value) {
				
				foreach ($value as $value)
					if (!in_array ($value, $arr))
						$diff[] = $value;
				
			}
			
			return $diff;
			
		}
		
		function __toString () {
			return json_encode ($this->pairs);
		}
		
	}