streams/Zotlabs/Web/HttpMeta.php

<?php

namespace Zotlabs\Web;


class HttpMeta {

	private $vars = null;
	private $og   = null;

	function __construct() {

		$this->vars = [];
		$this->og   = [];
		$this->ogproperties = [];

	}

	//Set Meta Value
	//   Mode:
	//      0 = Default - set if no value currently exists
	//	1 = Overwrite - replace existing value(s)
	//	2 = Multi - append to the array of values
	function set($property,$value,$mode=0) {
		$ogallowsmulti = ['image','audio','video'];
		if (strpos($property,'og:') === 0) {
			$count = 0;
			foreach ($this->og as $ogk => $ogdata) {
				if (strpos($ogdata['property'],$property) === 0) {
					if ($mode == 1) {
						unset($this->og[$ogk]);
						unset($this->ogproperties[$property]);
					}
					elseif ($mode == 0) {
						return;
					}
					elseif ($value == $ogdata['value']) {
						return;
					}
					else {
						$count++;
					}
				}
			}

			if ($value !== null) {
				//mode = 1 with value === null will delete the property entirely.
				$components = explode(':',$property);
				$ogp=$components[1];

				if (!$count || in_array($ogp,$ogallowsmulti)) {
					$this->og[]=['property'=>$property,'value'=>$value];
					$this->ogproperties[$property] = $property;
				}
			}
		} else {
			$this->vars[$property] = $value;
		}
	}

	function check_required() {
		if (
			in_array('og:title',$this->ogproperties) 
			&& in_array('og:type', $this->ogproperties) 
			&& (in_array('og:image',$this->ogproperties)
				|| in_array('og:image:url',$this->ogproperties))
			&& (array_key_exists('og:url', $this->ogproperties)
				|| array_key_exists('og:url:secure_url',  $this->ogproperties))
                        && array_key_exists('og:description',  $this->ogproperties)
		) {
			return true;
		}
		return false;
	}

	function get_field($field) {
		if (strpos($field,'og:') === 0) {
			foreach ($this->og as $ogdata) {
				if (strpos($ogdata['property'],$field) === 0) {
					$arr[$field][] = $ogdata['value'];
				}
			}
		}
		else {
			$arr = $this->vars;
		}
		
		if (isset($arr) && is_array($arr) && array_key_exists($field,$arr) && $arr[$field]) {
			return $arr[$field];
		}
		return false;
	}


	function get() {
		// use 'name' for most meta fields, and 'property' for opengraph properties
		$o = '';
		if ($this->vars) {
			foreach ($this->vars as $k => $v) {
				$o .= '<meta name="' . htmlspecialchars($k,ENT_COMPAT,'UTF-8',false) . '" content="' . htmlspecialchars($v,ENT_COMPAT,'UTF-8',false) . '" />' . "\r\n" ;
			}
		}
		if ($this->check_required()) {
			foreach ($this->og as $ogdata) {
				$o .= '<meta property="' . htmlspecialchars($ogdata['property'],ENT_COMPAT,'UTF-8',false) . '" content="' . htmlspecialchars($ogdata['value'],ENT_COMPAT,'UTF-8',false) . '" />' . "\r\n" ;
			}
		}
		if ($o) {
			return "\r\n" . $o;
		}
		return $o;
	}

}