Object Property Detection and Object Property Value Retrieval

object-has-get-property.php

<?php
/**
 * 
 * A robust way of retrieving the value of a a specified property in 
 * an instance of a class. 
 * 
 * Works with \stdClass objects created from arrays with numeric key(s) 
 * (the value of the propertie(s) with numeric key(s) in such \stdClass 
 * objects will be retrieved by this function).
 *  
 * 
 * @param mixed $obj
 * @param string|int $property
 * @param mixed $default_val
 * 
 * @return mixed
 * 
 * @throws \InvalidArgumentException
 * 
 */
function get_object_property_value($obj, $property, $default_val=null) {
    
    if( !is_object($obj) ) {
        
        $function = __FUNCTION__;
        $ns = __NAMESPACE__;
        $obj_type = gettype($obj);
        $msg = "Error [{$ns}::{$function}(...)]:"
        . " Object expected as first argument, `$obj_type` given.";
        throw new \InvalidArgumentException($msg); 
    }
    
    if( !is_string($property) && !is_int($property) ) {
        
        $function = __FUNCTION__;
        $ns = __NAMESPACE__;
        $property_type = gettype($property);
        $msg = "Error [{$ns}::{$function}(...)]:"
        . " String or Int expected as second argument, `$property_type` given.";
        throw new \InvalidArgumentException($msg); 
    }
    
    $return_val = $default_val;
    
    if( object_has_property($obj, $property) ) {
        
        if( $obj instanceof \stdClass ) {
            
            $obj_as_array = ((array)$obj);
            $return_val = $obj_as_array[$property];
            
        } else {
            
            $return_val = $obj->{$property};
        }
    }
    
    return $return_val;
}

/**
 * 
 * A more robust way than property_exists of checking if an instance of a class
 * has a specified property.
 * 
 * @param mixed $obj
 * @param string|int $property
 * 
 * @return bool
 * 
 * @throws \InvalidArgumentException
 * 
 */
function object_has_property($obj, $property) {
    
    if( !is_object($obj) ) {
        
        $function = __FUNCTION__;
        $ns = __NAMESPACE__;
        $obj_type = gettype($obj);
        $msg = "Error [{$ns}::{$function}(...)]:"
        . " Object expected as first argument, `$obj_type` given.";
        throw new \InvalidArgumentException($msg); 
    }
    
    if( !is_string($property) && !is_int($property) ) {
        
        $function = __FUNCTION__;
        $ns = __NAMESPACE__;
        $property_type = gettype($property);
        $msg = "Error [{$ns}::{$function}(...)]:"
        . " String or Int expected as second argument, `$property_type` given.";
        throw new \InvalidArgumentException($msg); 
    }
    
    return (
                property_exists($obj, $property)
                ||
                (
                    method_exists($obj, '__isset')
                    && method_exists($obj, '__get')
                    && isset($obj->{$property})    
                )
                ||
                (
                    $obj instanceof \stdClass
                    && array_key_exists( $property, ((array)$obj) )
                ) // hack for arrays with numeric keys that were
                  // cast into an object. E.g $item === ((object)[777=>'boo'])  
           );
}