Create an array of function arguments not equal to NULL?

Question

I'll start with explaining what my end goal is as there may be better solutions to it.

I have a function called updateUser which accepts the following parameters:

function updateUser($password = NULL, $name = NULL, $lastname = NULL, $age = NULL, $email = NULL, $relation = NULL)

As you can see I've set them to NULL, so if they aren't passed through the function they become blank. Right? (I hope I got that right)

The problem is that each of those arguments (which are passed) contains info for a user that's going to be sent in to a database, and I only want to include the passed variables in the query as I don't want to set the ones that are not passed to (blank) in the database.

And so I came up with the idea to take all the passed arguments and shove them into an array. And then loop through every item in the array and generate a string like:

$string = "$password, $email";

Gumbo · Accepted Answer · 2010-09-01 17:40:47Z

1

I guess it would be more flexible if you just pass one array containing the property/value pairs that should be updated:

function updateUser($props) {
    $names = array('password', 'name', 'lastname', 'age', 'email', 'relation');
    $arr = array();
    for ($names as $name) {
        if (isset($props[$names])) {
            $arr = "$name = '".mysql_real_escape_string($props[$names]).'"';
        }
    }
    if (!empty($arr)) {
        $query = "UPDATE … SET ".implode(',', $arr);
    }
}

Then you call this function with an array with the properties that should be updated:

updateUser(array('name'=>'User A', 'password'=>'secret'))

answered Sep 1, 2010 at 17:40

Gumbo

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Greg · Accepted Answer · 2010-09-01 19:50:18Z

1

Using the function call_user_func() (php.net docs), you can call your database INSERT or UPDATE commands depending on what data is passed to the function.

For example:

function updateUser($password = NULL, $name = NULL, $lastname = NULL,
    $age = NULL, $email = NULL, $relation = NULL)
{
    $array = array();

    // Create an array with indices of passed parameters:
    if($password !== NULL)  // !== to check for NULL and not empty string.
        $array["password"] = $password;
    if($name !== NULL)
        $array["name"] = $name;
    // etc...

    call_user_func("addToDb", $array);
}

function addToDb($detailsArray)
{
    foreach($detailsArray as $detail)
    {
        // Add $detail's key with $detail's value to database.
    }
}

edited Sep 1, 2010 at 19:50

answered Sep 1, 2010 at 17:31

Greg

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2 Comments

Freyja Over a year ago

this is wrong usage of call_user_func_array(). call_user_func_array() takes each element in the second parameter (which should be an array) and uses it as a separate parameter, i.e. call_user_func_array('foobar', array('a', 'b', 'c')); would be the equivalent of call_user_func('foobar', 'a', 'b', 'c'); or simply foobar('a', 'b', 'c'); (see call_user_func())

qwerty Over a year ago

After a bit of struggling with it i finally got it working. When i first looked at it i was like "wtf? How would that possibly work?" but then i read through it and it became a bit more logic. It works great, thanks.

Lekensteyn · Accepted Answer · 2010-09-01 17:30:21Z

0

Gets all arguments and filter variables away which are not a string.

$arguments = func_get_args();
array_filter($arguments, 'is_string');
//$arguments will be an array with numeric indices

answered Sep 1, 2010 at 17:30

Lekensteyn

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1 Comment

qwerty Over a year ago

I found a better solution to it, but i'll keep this in mind. I searched the PHP archive for a function like that for an eternity, lol. Thanks for the post!

2ndkauboy · Accepted Answer · 2010-09-01 17:33:59Z

0

I think the problem is that you might not call the function correctly. When you do it like this:

updateUser('pass', 'user', '', '', '[email protected]');

than the values of $lastname and $age will not be null, but an empty string. But if you call it like this:

updateUser('pass', 'user', null, null, '[email protected]');

they will remain null.

answered Sep 1, 2010 at 17:33

2ndkauboy

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