[RESOLVED] Calling Class Functions Conditionally

[reyn]

I have a form with several sections each one enabled by a checkbox allowing input of parameters. When this form is submitted I want to call a class object with only the class functions called that have the checkbox enabled.

$variable = new Thumbnail($source,$_POST['maxwidth'],$_POST['maxheight'],$tsource,$_POST['JpegCompression'],'
	"bevel('.$_POST['BevelEdgeWidth'].','.$_POST['BevelHexLtColor'].','.$_POST['BevelHexDkColor'].')",
   	"greyscale('.$_POST['GreyScaleIntRed'].','.$_POST['GreyScaleIntGreen'].','.$_POST['GreyScaleIntBlue'].')",    

    "ellipse('.$_POST['EllipseHexBkColor'].')",
	"merge('.$_POST['MergeImagePath'].','.$_POST['MergeXstart'].','.$_POST['MergeYstart'].','.$_POST['MergeOpacity'].','.$_POST['MergeTransColor'].')",
	"frame('.$_POST['FrameHexLtColor'].','.$_POST['FrameHexDkColor'].','.$_POST['FrameIntWidthMidBit'].')",
	"drop_shadow('.$_POST['DropShadowWidth'].','.$_POST['DropShadowColor'].','.$_POST['DropShadowBkColor'].')",
	"motion_blur('.$_POST['MotionBlurNumLines'].','.$_POST['MotionBlurHexBkColor'].')",
	"round_edges('.$_POST['RoundEdgeRadius'].','.$_POST['RoundEdgeBkColor'].','.$_POST['RoundEdgeAntiAlias'].')"');

So if only the Bevel checkbox is enabled I only want to call the class bevel function and if several checkboxes are enabled I want to call those class functions.

It's having the functions in the class that's throwing me.
What is the best way to conditionally call class functions?

Thanks
Frank

[thorpe]

its no different to calling any other function. im sorry, but i cant comprehend your code, so an example.

if (conditionmet) {
  $obj->method();
}

[reyn]

I am having trouble explaining this, please bear with me.
This is a simpler version of what I want to do.

include_once('thumbnail_create.php');

$variable = new Thumbnail('input image path',maxwidth,maxheight,'output image path',jpeg quality,'
    "greyscale()",
    "ellipse(\'C3DDEE\')",
    "bevel(7,\'FFFFFF\',\'111144\')",
    "round_edges(4,\'C3DDEE\',1)"');

thumbnail_create.php is the class I am including, I want to put a front end form to it.
I have changed the function parameters from eg "ellipse(\'C3DDEE\')", to "ellipse('.$_POST['EllipseHexBkColor'].')",etc: where EllipseHexBkColor is the variable passed from the form. So far this works. On the form all the parameters of each function are enabled by a checkbox. So if I only want to greyscale the image I just check the greyscale checkbox and fill in the greyscale parameters.
The submit button should then run
$variable = new Thumbnail('images/ms_ionian_0001.jpg',200,120,'thumbs/test_thumb.jpg',85,'
"greyscale()"'); only.

If more than one checkbox is checked I want to stack the function calls as per the code example with as many different function calls as are checked on the form.
I believe I can check for the enabled checkbox using isset on/off what I am trying to understand is where should this check be done in the code and how best to conditionally call greyscale() and /or bevel() and/or ellipse(0 etc: depending on which checkboxes are "on".

[thorpe]

i think your getting functions and arguments mixed up. if you seperated all the functionality of each argument into a seperate function this would be easy. as of now, your only calling one method (function), with variable arguments. maybe you could pass in your checked values as an array, and let the class itself sort it all out.

could we possibly see your thumbnail class?

[reyn]

Yes, what's confusing me is instantiating a new object using arguments which are functions in the class the object is based on. I now have it a bit clearer. The class, it is not mine, if I could write code like that I wouldn't be here. This class is freely available for use in any non-profit applications what it does is here. http://www.teckis.com/scriptix/thumbnails/teck.html and download here http://www.teckis.com/scriptix/thumbnails/subpage/GD2_class_distro/teck.html

Now perhaps I can ask the right question, how should I call the method with arguments relating to the forms enabled checkboxes.

So checkbox 1 enabled call method(argument 1)
checkbox 1 and 2 enabled call method(argument 1, argument 2)
checkbox 1 and 2 and 6 enabled call method( you get the picture)

There must be a nicer way than having numerous method calls depending on the number of arguments required.

What I am after is:

if isset cbox1 = yes then
call method(argument1)
if isset cbox1 and 4 and 5 = yes then
call method(argument1,argument4,argument5)

but a lot cleaner than this.
I maybe looking at this the wrong way, but that's why I am here.

[Shrike]

What a strange class. It looks as if the last argument is eval()'d to determine which methods to call. I think you would be better off calling the methods individually. A caveat of using optional function arguments is that the optional arguments must be on the right side of the argument list. Imagine you want to use argument 1 and 3 but leave the 2nd with the default value - how does the code determine that the second value you pass is intended for the 3rd argument?

With that in mind you could simply iterate over the $POST array and determine which checkboxes are checked, and thus which methods to call. Some sort of mapping might be appropriate to stop the client calling methods which it shouldn't.

$thumb = new Thumbnail( $args_you_know_are_present );
$methods = array (
  'bev' => 'bevel',
  'elip' => 'elipse'
);
foreach( $_POST as $key => $value )
{
  if( in_array( $key, $methods ))
  {
    $thumb->$key( $_POST['relevant_values'] );
  }
}

You could use a similar approach to build up a string to use in the class constructor, but that's up to you. Also bear in mind that $_POST data should checked before use (which I haven't done).

[thorpe]

yeah... i havent even looked at the class, but just from the way you call it in your examples it doesn't seem too practical.