History of ClassStructure
Version 2
Some detail:
A new class structure is defined from which all Tiki classes inherit. The existing lib/* directory structure will be maintiained, and all existing libs can stay in place as migration takes place. The basic class inheritance looks like:
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 TikiFeatureGroup class might be designed, but this is uncertain for now.
A few rules of thumb:
Example: imaginary TikiFeature derived class, see TikiPage for real example
class TikiFeature extends TikiBase
{
// member var that hold corresponding data
var mRow;
function TikiFeature( $iFeatureID = NULL ) {
// be sure to call base constructor!!!
TikiBase::TikiBase();
$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 );
}
}
A new class structure is defined from which all Tiki classes inherit. The existing lib/* directory structure will be maintiained, and all existing libs can stay in place as migration takes place. The basic class inheritance looks like:
- class TikiFeature - Cool feature such as Wiki or Blog or Article, etc...
- --> class TikiContent - Virtual Base class upon which all "content" oriented classes derive (wiki, article, etc. )
- ----> class TikiBase - a few utility functions common to every Tiki class
- ------> class TikiDB - little changed from current core
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 TikiFeatureGroup class might be designed, but this is uncertain for now.
A few rules of thumb:
- There should be _NO_ presentation code (no smarty assignments, no html generation, etc) in any class derived from TikiBase. Two notable exceptions might be extreme error conditions or convenient $rs->GetMenu() calls
- 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 TikiFeature derived class, see TikiPage for real example
class TikiFeature extends TikiBase
{
// member var that hold corresponding data
var mRow;
function TikiFeature( $iFeatureID = NULL ) {
// be sure to call base constructor!!!
TikiBase::TikiBase();
$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 );
}
}