BERT: New page: {{howto|Easy|BERT }} == Intro == If you want to use the power of any attribute without having database I/O involved either in a normal node or maybe in the admin screen, like what the...

2008-03-25T20:11:48Z

New page: {{howto|Easy|BERT }} == Intro == If you want to use the power of any attribute without having database I/O involved either in a normal node or maybe in the admin screen, like what the...

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{{howto|Easy|[[BERT]] }}

== Intro ==
If you want to use the power of any attribute without having database I/O involved either in a normal node or maybe in the admin screen, like what the dummy attribute does. This how to will help you with that.

== Creating a custom attribute without I/O ==
Create your attribute by extending the one you desire. In this case I'm extending the list or 'dropdown box'. You then need to change the loadType and storeType to return a value of 0 so it doesn't interface with the database.

<syntaxhighlight lang="php">
useattrib("atklistattribute");
class listNoIO extends atkListAttribute
{
function listNoIO($name, $optionArray, $valueArray="", $flags=0, $size=0 )
{
$this->atkListAttribute($name, $optionArray, $valueArray, $flags, $size );
// this attribute will only be visible in edit screens:
$this->addFlag(AF_HIDE); $this->removeFlag(AF_HIDE_ADD);
}
function loadType()
{
// this makes sure this attribute does not partake in the query that loads
// data. Since we aren't a real relationship, we don't have anything to load.
return 0;
}
function storageType()
{
return 0;
}
}
</syntaxhighlight>

== Using that attribute in your node ==
Add it to your node. Upon Saving via the Edit or Add the $record will contain these values and can be used in places like validate or postUpdate
<syntaxhighlight lang="php">
useattrib("yourmodule.listnoio");

class yournode extends atkNode {
function yournode () {
$attr = &$this->add(new listNoIO( "adminview",
array( "All","Not_All") ,
array( "A","N"), AF_LIST_NO_NULL_ITEM ));
}

function postUpdate(&$record)
{
if ( $record['adminview'] == 'N' ) {
$this->doSomethingSpecial( $record );
}
return true;
}
}
</syntaxhighlight>

== Using it to polymorphism your admin list ==
Lets put this list attribute in the Header area and use it to change our columns.
<syntaxhighlight lang="php">
useattrib("yourmodule.listnoio");

class yournode extends atkNode {
function yournode () {
GLOBAL $ATK_VARS;
// change it to always be hidden
$attr = &$this->add(new listNoIO( "adminview",
array( "All","Not_All") ,
array( "A","N"), AF_HIDE|AF_LIST_NO_NULL_ITEM ));

// make it happen 'onChange' of the value and pass it back the one selected
$attr->addOnChangeHandler( " window.location='".str_replace("'","\'",$_SERVER['REQUEST_URI'])."&chgadminview='+newvalue;");

// See if we already have an adminview value set
$session = &atkSessionManager::getSession();
$adminView = $session['adminview'];

// check to see if our adminview dropdown was changed
if ( isset( $ATK_VARS['chgadminview'])){
$adminView = $ATK_VARS['chgadminview'] ;
// save our admin value on our session stack so we can reference it when we
// come back to the admin screen
$session['adminview'] = $adminView;
}

if ( isset($adminView) && $ATK_VARS['atkaction'] == 'admin' ) {
$attr->setSelected( $adminView ); // set the selected one as default
if ( $adminView == 'N' ) {
// lets say we have 2 attributes which are normally not on the
// admin screen and we want to put them there
foreach ( array('Attr1','Attr2') as $var ) {
$attr = &$this->getAttribute( $var );
$attr->removeFlag( AF_HIDE_LIST );
}

}
}

// put the attribute in the Header area
function adminHeader(){
// setup adminview list box for viewing just finals or final 4
$attr=&$this->getAttribute("adminview");
// please note: $rec is blank here
$help_text = '<tr><td align="left">'."VIEW: ".$attr->edit( $rec, 'edit') . '</td></tr>';
return $help_text;
}
}
</syntaxhighlight>

Usage without DB I/O + Polymorphism - Revision history

BERT: New page: {{howto|Easy|BERT }} == Intro == If you want to use the power of any attribute without having database I/O involved either in a normal node or maybe in the admin screen, like what the...