Issue in gateways with METHOD_HTML_FORM redirection method, if multidimensional is passed.

[knit-pay]

The below code fails if we pass a multidimensional array to html_hidden_fields function.

wp-pay-core/src/Util.php

Lines 211 to 213 in ecb3e11

	foreach ( $data as $name => $value ) {
	$html .= sprintf( '<input type="hidden" name="%s" value="%s" />', esc_attr( $name ), esc_attr( $value ) );
	}

In Some payment gateways, data is passed as multidimensional array. See example below
https://razorpay.com/docs/payments/payment-gateway/web-integration/hosted/build-integration/#code-to-add-pay-button

Here field prefill[name] is creating an issue.

Before running the loop, if we will call below function, issue will be fixed.

$data = self::flatten_array($data);

	public static function flatten_array($array, $prefix = '', $parent = true) {
	    $result = array();
	    foreach($array as $key=>$value) {
	        if(is_array($value)) {
	            if($parent){
	                $result = $result + self::flatten_array($value, "{$key}", false);
	            }else {
	                $result = $result + self::flatten_array($value, "{$prefix}[{$key}]", false);
	            }
	        } else if ($parent){
	            $result["{$prefix}{$key}"] = $value;
	        }
	        else {
	            $result["{$prefix}[{$key}]"] = $value;
	        }
	    }
	    return $result;
	}

Do you have any better suggestion for the same?

[remcotolsma]

You want to pass in a an array like:

return [
	'key_id'       => 'YOUR_KEY_ID',
	'amount'       => '1001',
	'order_id'     => 'razorpay_order_id',
	'name'         => 'Acme Corp',
	'description'  => 'A Wild Sheep Chase',
	'image'        => 'https://cdn.razorpay.com/logos/BUVwvgaqVByGp2_large.jpg',
	'prefill' => [
		'name'    => 'Gaurav Kumar',
		'contact' => '9123456780',
		'email'   => '[email protected]',
	],
	'notes'   => [
		'shipping address' => 'L-16, The Business Centre, 61 Wellfield Road, New Delhi - 110001',
	],
	'callback_url' => 'https://example.com/payment-callback',
	'cancel_url'   => 'https://example.com/payment-cancel',
];

You can just build a flat array?

return [
	'key_id'                  => 'YOUR_KEY_ID',
	'amount'                  => '1001',
	'order_id'                => 'razorpay_order_id',
	'name'                    => 'Acme Corp',
	'description'             => 'A Wild Sheep Chase',
	'image'                   => 'https://cdn.razorpay.com/logos/BUVwvgaqVByGp2_large.jpg',
	'prefill[name]'           => 'Gaurav Kumar',
	'prefill[contact]'        => '9123456780',
	'prefill[email]'          => '[email protected]',
	'notes[shipping address]' => 'L-16, The Business Centre, 61 Wellfield Road, New Delhi - 110001',
	'callback_url'            => 'https://example.com/payment-callback',
	'cancel_url'              => 'https://example.com/payment-cancel',
];

We could implement support for multidimensional arrays, we don't really need this ourselves, so maybe this should remain gateway territory?

https://www.php.net/manual/en/function.http-build-query.php

---

Solution with RecursiveIteratorIterator?

<?php

$data = [
	'key_id'       => 'YOUR_KEY_ID',
	'amount'       => '1001',
	'order_id'     => 'razorpay_order_id',
	'name'         => 'Acme Corp',
	'description'  => 'A Wild Sheep Chase',
	'image'        => 'https://cdn.razorpay.com/logos/BUVwvgaqVByGp2_large.jpg',
	'prefill' => [
		'name'    => 'Gaurav Kumar',
		'contact' => '9123456780',
		'email'   => '[email protected]',
	],
	'notes'   => [
		'shipping address' => 'L-16, The Business Centre, 61 Wellfield Road, New Delhi - 110001',
	],
	'callback_url' => 'https://example.com/payment-callback',
	'cancel_url'   => 'https://example.com/payment-cancel',
	1 => 'test',
];

$iterator = new class( new RecursiveArrayIterator( $data ) ) extends RecursiveIteratorIterator {
	function key() {
		$key = $this->getSubIterator( 0 )->key();

		for ( $i = 1; $i <= $this->getDepth(); $i++ ) {
			$key .= '[' . $this->getSubIterator( $i )->key() . ']';
		}

		return $key;
	}
};

foreach ( $iterator as $key => $item ) {
    var_dump( $key );
    var_dump( $item );
    echo PHP_EOL;
}

[knit-pay]

You want to pass in a an array like:

Yes, I need to pass an array like the first one in post form.

You can just build a flat array?

Yes, need to pass a flat array like the one you provided. The first array is getting used for another purpose also. So, developing a second array directly is not possible. Either I will have to convert the normal array to a flat array within the get_output_fields function before returning. Using a function similar to the function given below or I will have to recreate the complete array. For the time being, I have already handled it within my gateway code to convert it within the get_output_fields function. It's just a suggestion that we can handle it within the wp-pay-core code itself as other gateways might also need similar functionality.

	public static function flatten_array($array, $prefix = '', $parent = true) {
	    $result = array();
	    foreach($array as $key=>$value) {
	        if(is_array($value)) {
	            if($parent){
	                $result = $result + self::flatten_array($value, "{$key}", false);
	            }else {
	                $result = $result + self::flatten_array($value, "{$prefix}[{$key}]", false);
	            }
	        } else if ($parent){
	            $result["{$prefix}{$key}"] = $value;
	        }
	        else {
	            $result["{$prefix}[{$key}]"] = $value;
	        }
	    }
	    return $result;
	}

https://www.php.net/manual/en/function.http-build-query.php

Yes, this function is good for creating query strings. add_query_arg or http_build_query can be used for sending parameters in GET requests. But I think we can't use it for POST form submission. Correct me if I am wrong.

Solution with RecursiveIteratorIterator?

Thanks for the suggestion, I will try to use this also.

What do you think, I should handle this within gateway or you can include it in wp-pay-core also?

[remcotolsma]

What do you think, I should handle this within gateway or you can include it in wp-pay-core also?

I think we could include this in the core library, it might be useful if this works like for example like the body argument in the wp_remote_post function. I think the WordPress HTTP library is using the http_build_query function for this. I will discuss this internally with @rvdsteege and double check if a RecursiveIteratorIterator solution is handy.

• https://stackoverflow.com/questions/4543500/form-input-field-names-containing-square-brackets-like-fieldindex
• https://github.com/php/php-src/blob/php-8.1.10/ext/standard/http.c#L222-L249
• https://github.com/php/php-src/blob/php-8.1.10/ext/standard/string.c#L4754-L4775
• array_dot → https://laravel.com/docs/4.2/helpers → https://github.com/laravel/framework/blob/bbce25bd823133f6a5a724f2d62680b711f1d0df/src/Illuminate/Collections/Arr.php#L103-L123

function flat( $data, $parent = '', $result = [] ) {
    foreach ( $data as $key => $item ) {
        if ( '' !== $parent ) {
            $key = $parent . '[' . $key . ']';
        }

        if ( is_array( $item ) ) {
            $result = flat( $item, $key, $result );
        } else {
            $result[ $key ] = $item;
        }
    }
    
    return $result;
}

var_dump( flat( $data ) );

[remcotolsma]

Naming helper function, perhaps like array_dot:

private static function array_square_bracket( $data, $parent = '', $result = [] ) {
    foreach ( $data as $key => $item ) {
        if ( '' !== $parent ) {
            $key = $parent . '[' . $key . ']';
        }

        if ( is_array( $item ) ) {
            $result = self::array_square_bracket( $item, $key, $result );
        } else {
            $result[ $key ] = $item;
        }
    }
    
    return $result;
}