[Chameleon] changing class name and expression programmatically

[Normand Savard]

Anand Akmanchi wrote:

> Hi members
>
> thanks Norm for your help,..it worked out wonderfully fine
>
> I have been able to query, retrieve and display a postgis layer
> and now would like to style it
>
> the classitem is a column containing integer values in the database table
> I want to break it up into five equal or natural breaks interval classes
> I am able to compute statistics like mean, stdev etc. on the column 
> using PHP
>
> how do I manipulate the layer's classitem containing five classes
> I want to access them using the class name
> then set the class name to something meaningful like upper/lower
> limits of interval
> and set the expression for that class
>
> thanks in advance
>
>
Anand,

Do you classes already exist in your layer?  I don't know if I 
understand well all you want to accomplish but I give it a try (see below).

Norm 

 $szMyClassName = set this value to whatever your class name is


$oMap = $this->moMapObject->oMap;
$oLayer = @$oMap->getlayerbyname($this->mszLayerName);
$oClass =getClassByName($oLayer, $szMyClassName);
$oClass->setexpression(type in your expression here);




function getClassByName($oLayer, $szName)
{
      $nClasses = $oLayer->numclasses;

        for($j=0;$j<$nClasses;$j++)
        {
            $oClass = $oLayer->getClass($j);
            if ( $oClass->name == trim( $szName) )
            {
                return $oClass;
            }    
        }

}