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Fri 09 of Jan, 2009 (22:57 UTC)

bitweaver - Web Application Framework and CMS

Web Application Framework and CMS

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ClassStructure

Created by: spiderr, Last modification: Tue 23 of Jan, 2007 (02:16 UTC)
Some detail:

All bitweaver classes follow the same structure. The basic class inheritance looks like:

  • class BitFeature - Cool feature such as Wiki or Blog or Article, etc...
  • --> class LibertyAttachable - Virtual Base class which adds handling of attached files and resources.
  • ----> class LibertyContent - Virtual Base class upon which all "content" oriented classes derive (wiki, article, etc. )
  • ------> class BitBase - a few utility functions common to every Bit class, and includes member variable mDb, a shared BitDb database object for all objects derived from BitBase.

An instantiated class should typically represent a single object, such as a wiki page or article. Aggregate data functions are currently in the same class. Perhaps a derived BitFeatureGroup class might be designed, but this is uncertain for now.

A few rules of thumb:
  1. There should be _NO_ presentation code (no smarty assignments, no html generation, etc) in any class derived from BitBase. Two notable exceptions might be extreme error conditions or convenient $rs->GetMenu() calls
  2. All derived class should support a core set of methods. In real OO land, there would be several pure virtual functions named: load, store, verify, expunge (delete has a naming conflict with native php function). These functions should always follow these names so derived classes can properly call into base methods

Example: imaginary BitFeature derived class, see BitPage for real example
 class BitFeature extends BitBase
 {
  // member var that hold corresponding data
  var mRow;
 
    function BitFeature( $iFeatureID = NULL ) {
        // be sure to call base constructor!!!
        BitBase::BitBase();
        $this->mFeatureID = $iFeatureID;
    }
 
    function load() {
        if( $this->mFeatureID ) {
            $this->mRow = {... select data from db where feature_id=$this->mFeatureID ...}
        }
        return( count( $this->mErrors ) == 0 );
    }
 
    // This verifies data integrity. NOTE: pass by reference is crucial, because
    // some modifications might be necessary (length truncation, etc.);
    function verify( &$inParams ) {
        // clean up variables
        foreach( array_keys($inParams) as $key ) {
            $inParams[[$key] = trim( $inParams[[$key] );
        }
 
        if( empty( $inParams[['required_column'] ) ) {
            $this->mErrors[['required_column'] = SOME_ERROR_MESSAGE;
        } elseif( strlen( $inParams[['required_column'] ) > FEATURE_LENGTH ) {
            $inParams[['required_column'] = substring( $inParams[['required_column'],
                                                      0, FEATURE_LENGTH );
        }
 
        {... continue testing hash values various conditions ...}
 
        return( count( $this->mErrors ) == 0 );
    }
 
    //	this method stores the data.
    function store( &$inParams ) {
        // ALWAYS call our verify first to ensure data is safe to go into db
        if( $this->verify( $inParams ) ) {
                $this->mDB->StartTrans();
            if( data exists ) {
               {... update existing rows ...}
            } else {
                {... insert new row ...}
            }
            $this->mDB->CompleteTrans();
        }
        return( count( $this->mErrors ) == 0 );
    }
 
    funciton expunge() {
        {... delete appropriate rows for this feature in all necessary tables ...}
        return( count( $this->mErrors ) == 0 );
    }
 }

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