[Resolved] problem with array_walk() or usort() with bundling and OO PHP

[ppowell]

I am sorry I can't explain this, but I simply can't 🙁

This is what I want to do, consider this:

$_POST['agencies'] = array('abc', 'def', 'xyz');

Ok you have a form with like checkboxes or whatever that you enter more than one item.

I want to convert

$_POST['agencies']

into

$POST['agencies_bundle'] = $POST['agencies'][0] . $delimiter . $POST['agencies'][1] . $delimiter . $POST['agencies'][2]

Ok, I hope you got that so far, that's what I'm trying to do. Now I thought of using either array_walk() or usort() or whatever to accomplish this but saving time by bundling $_POST fields into an array itself. This is to save on long lines of code to make it more elegant.

The problem is that my methods produce the following:

$_POST['agencies_bundle'] = '' when it should be 'abc,def,xyz'

Basically, what did I do wrong?

Thanx
Phil

class ActionPerformer extends InternsActionPerformer {
    /**
     * Edit existing intern.  Will be void method with no functionality to use as redirect to db
     *
     * *NOTE* This method will override InternsActionPerformer::edit() method intentionally to allow for usage of specific code
     *
     * @access public
     */
    function &edit() {                                            //  STATIC VOID METHOD
        global $section, $redirectArray, $projectAcronym;
        $bundleArray = array('internship_time', 'agencies', 'internship_time', 'internship_area');
        usort($bundleArray, array($this, 'bundle'));
        print_r($_POST); die('');
        if ($this->isSuccessful) unset($_SESSION["${projectAcronym}_mainDisplay"]);
        if ($this->isSuccessful && $redirectArray[$section]['edit']) echo $this->getHTMLRedirect('edit', '&willFlushResult=1');
    }
}

class InternsActionPerformer extends DBActionPerformer {
    /**
     * Bundle together $_POST array items into a single string tagged with "_bundle" to distinguish from original $_POST array key name
     *
     * @access protected
     * @param mixed $field
     * @param mixed $delimiter
     */
    function &bundle($field, $delimiter) {                                                    // STATIC VOID METHOD
        print_r("field = $field and delimiter = $delimiter<P>");
        ${$field} = $_POST[$field];
        print_r("<P>field = $field = "); print_r(${$field}); print_r("<P>");
        $max = (@in_array('**OTHER**', ${$field})) ? @array_search('**OTHER**', ${$field}) : (@sizeof(${$field}) - 1);
        print_r("max = $max<P>");
        if ((int)$max > 0 && @in_array('**OTHER**', ${$field})) ${$field . "[$max]"} = 'other';        // RE-INSERT "other" INTO BUNDLE
        for ($i = 0; $i < @sizeof(${$field}); $i++) $bundle .= ${$field . "[$i]"} . $delimiter;
        if ($_POST["${field}_other"]) $bundle .= $_POST["${field}_other"];
        $bundle = substr($bundle, 0, strrpos(trim($bundle), $delimiter));
        $_POST["${field}_bundle"] = $bundle;                                                // ADD TO $_POST     

    }

}

[mtmosier]

What you describe is the impode function.

As for your usort callback method, you are aware that usort will pass two elements of the array you're sorting to this method, right? Judging by the name of "$delimiter" I would guess that you're expecting something like a comma to be the second parameter.

[ppowell]

Ok I give up.. This worked:

	/**
	 * Edit existing intern.  Will be void method with no functionality to use as redirect to db
	 *
	 * *NOTE* This method will override InternsActionPerformer::edit() method intentionally to allow for usage of specific code
	 *
	 * @access public
	 */
	function &edit() {											//  STATIC VOID METHOD
		global $section, $redirectArray, $projectAcronym;
		$bundleArray = array('internship_time', 'agencies', 'internship_time', 'internship_area');
		foreach ($bundleArray as $field) $this->bundle($field, ',');
		print_r($_POST); die('');
		if ($this->isSuccessful) unset($_SESSION["${projectAcronym}_mainDisplay"]);
		if ($this->isSuccessful && $redirectArray[$section]['edit']) echo $this->getHTMLRedirect('edit', '&willFlushResult=1');
	}

It's easy: stop using array_walk()!

Does array_walk() work for ANYONE??? I've been doing PHP for years and not once have I ever got it to work and yet it looks so extremely easy!! But in this case it never does, no matter what I do!

In the bundle() method I jused @join() and it joined together, however, $delimiter was everything but ',', it was either a number, the value of $field or null every time.

array_walk(): i hate it!

Phil

[mtmosier]

The original code you posted didn't include array_walk, so I can't say whether you did anything wrong. A quick search over my php files shows that I used array_walk once.

$r = mysql_query($q);
if ($r && ($row = mysql_fetch_assoc($r))) {
    array_walk($row, 'strip_tags_array');
    //  Do something
}

function strip_tags_array(&$val, $key) {
    $val = strip_tags($val);
}

[ppowell]

Ok it originally looked like this:

	/**
	 * Edit existing intern.  Will be void method with no functionality to use as redirect to db
	 *
	 * *NOTE* This method will override InternsActionPerformer::edit() method intentionally to allow for usage of specific code
	 *
	 * @access public
	 */
	function &edit() {											//  STATIC VOID METHOD
		global $section, $redirectArray, $bundleArray, $projectAcronym;
		array_walk($bundleArray[$section], array($this, 'bundle'), $delimiter); // THIS FAILS - PRODUCES THE ARRAY KEY AS $delimiter INSTEAD OF ',' AS $delimiter
		if ($this->isSuccessful) unset($_SESSION["${projectAcronym}_mainDisplay"]);
		if ($this->isSuccessful && $redirectArray[$section]['edit']) echo $this->getHTMLRedirect('edit', '&willFlushResult=1');
	}

Someone suggested I try this:

array_walk($bundleArray[$section], 'InternsActionPerformer::bundle', $delimiter);

Also failed but looked better, maybe I did it wrong:

Warning: array_walk(): Unable to call InternsActionPerformer::bundle() - function does not exist

There is a class InternsActionPerformer and it has a method 'bundle'.

Phil

[mtmosier]

Applies the user-defined function funcname to each element of the array array. Typically, funcname takes on two parameters. The array parameter's value being the first, and the key/index second. If the optional userdata parameter is supplied, it will be passed as the third parameter to the callback funcname.

Quoth the manual. Notice how the first parameter is the element's value, and the second is the element's key? The third parameter is the user data.

Your array reference to the bundle method was correct. You just have to add another parameter ($key) to the bundle method, which you can ignore if you don't need it. Make $delimiter the third parameter.

[ppowell]

Thanx for the clarification, someday I'll master array_walk(), but not today.

I am sticking with foreach loop instead because to do what you suggest would mean altering the parameter order of bundle(), which would affect several other classes and instances referencing that method, and that's too many lines of code to change just for one instance of edit() needing it that way.

My question though is this: what if you will have more than 3 parameters? Would you have to "bundle" the 3rd parameter into an array (or object) just to use within the possible 3-parameter-max handling by array_walk()?

sigh
Phil

[mtmosier]

I am sticking with foreach loop instead because to do what you suggest would mean altering the parameter order of bundle(), which would affect several other classes

I think for established functions you would usually add a translation function for array_walk to use. Like I did with strip_tags in the earlier example.

Would you have to "bundle" the 3rd parameter into an array (or object) just to use within the possible 3-parameter-max handling by array_walk()?

Afraid so, yeah.

[Drakla]

What the hell is wrong with array_walk - here's a simple example that trims and strips the request array if it's needed

clean_array($_REQUEST);

function clean_array(&$value)
{
	if (is_array($value))
		array_walk($value, __FUNCTION__);
	else
	{
		$value = trim($value);

	if(get_magic_quotes_gpc())
		$value = stripslashes($value);
}
}

And here's a slightly more upbeat version using methods

class Request_Handler
{
	var $data;				// copy of request data, auto de-slashed if need be
	var $reqFilled;			// a list of fields that have to be filled when verify is called
	var $reqNumeric;		// fields that have to be numeric
	var $errors;			// array of error messages

function Request_Handler()
{
	$this->data 		= $_REQUEST;
	$this->errors 		= array();
	$this->reqFilled 	= array();
	$this->reqNumeric 	= array();

	if (get_magic_quotes_gpc())
		$this->strip();
}

function strip()
{
	$this->recurse_it($this->data, 0, 'stripslashes');
}

function trim()
{
	$this->recurse_it($this->data, 0, 'trim');
}

function specialchars()
{
	$this->recurse_it($this->data, 0, 'htmlspecialchars');
}

function escape()
{
	$this->recurse_it($this->data, 0, 'mysql_escape_string');
}

	// hope you appreciate how lovely this is

function recurse_it(&$in, $dead, $function)
{
	if ( is_array($in) )
		array_walk($in, array($this, 'recurse_it'), $function);
	else
		$in = $function($in);
}

function reset()
{
	$this->Request_Handler();
}

function verify()
{
	$errCnt = 0;

	foreach ($this->reqFilled as $key)
	{	if (empty($this->data[$key]))
		{
			$this->errors[] = 'field "' . $key. '" empty';
			$errCnt++;
		}
	}

	foreach ($this->reqNumeric as $key)
	{	if (!isset($this->data[$key]) || !is_numeric($this->data[$key]))
		{
			$this->errors[] = 'field "' . $key. '" not numeric';
			$errCnt++;
		}
	}

	return $errCnt ? false : true;
}

function set_req_filled($rf)
{
	$this->reqFilled = $rf;
}

function set_req_numeric($rn)
{
	$this->reqNumeric = $rn;
}
}

[ppowell]

Two questions:

1) What version of PHP are you using?

2) Are you using OO PHP or procedural PHP?

Phil