php trait using another trait
Solution 1
Maybe because readSetting is actually called getSetting ?
Solution 2
Code reuse is one of the most important aspects of object-oriented programming.
A simple example of Multiple Traits
and Composing Multiple Traits
by which you can easily analyse you situation.
- Using multiple traits
A class can use multiple traits. The following example demonstrates how to use multiple traits in the IDE class. It simulates the C compilation model in PHP for the sake of demonstration.
<?php
trait Preprocessor{
function preprocess() {
echo 'Preprocess...done'. '<br/>';
}
}
trait Compiler{
function compile() {
echo 'Compile code... done'. '<br/>';
}
}
trait Assembler{
function createObjCode() {
echo 'Create the object code files... done.' . '<br/>';
}
}
trait Linker{
function createExec(){
echo 'Create the executable file...done' . '<br/>';
}
}
class IDE{
use Preprocessor, Compiler, Assembler, Linker;
function run() {
$this->preprocess();
$this->compile();
$this->createObjCode();
$this->createExec();
echo 'Execute the file...done' . '<br/>';
}
}
$ide = new IDE();
$ide->run();
- Composing multiple traits
A trait can be composed of other traits by using the use statement in the trait’s declaration. See the following example:
<?php
trait Reader{
public function read($source){
echo sprintf("Read from %s <br/>",$source);
}
}
trait Writer{
public function write($destination){
echo sprintf("Write to %s <br/>",$destination);
}
}
trait Copier{
use Reader, Writer;
public function copy($source,$destination){
$this->read($source);
$this->write($destination);
}
}
class FileUtil{
use Copier;
public function copyFile($source,$destination){
$this->copy($source, $destination);
}
}
Admin
Updated on July 09, 2022Comments
-
Admin almost 2 years
I have a trait which is using another trait, and now I'm getting errors about functions that don't exist in classes. I have simplified the code:
settings.php:
<?php trait settings{ protected function getSetting($type, $setting){ // read setting from config.ini try{ $configFile=dirname(__FILE__)."/../config.ini"; if(!file_exists($configFile)||!is_file($configFile))throw new Exception("Config file was not found. "); $configContents=parse_ini_file($configFile,true); if(is_array($configContents)&&array_key_exists($type,$configContents)&&is_array($configContents[$type])&&array_key_exists($setting,$configContents[$type]))return $configContents[$type][$setting]; else throw new Exception("Setting ".$setting." could not be found in ".$type."."); } catch(Exception $e){throw new Exception($e->getMessage());} } } ?>
database.php
<?php trait database{ use settings,session; private $pdo; protected function connect(){ // connect to database try{ $this->pdo=new PDO("mysql:host=".$this->getSetting("db","host").";dbname=".$this->getSetting("db","database"),$this->getSetting("db","user"),$this->getSetting("db","password")); $this->init(); } catch(PDOException $e){throw new Exception($e->getMessage());} } } ?>
users.php
<?php class users{ use database; public function __construct(){ try{ $this->connect(); } catch(Exception $e){throw new Exception($e->getMessage());} } public function __destruct(){ unset($this); } public function isAdmin(){ try{ if($this->loginStatus()===true){ } else return false; } catch(Exception $e){throw new Exception($e->getMessage());} } public function loginStatus(){ if(!$this->getSession("tysus")||!$this->getSession("tyspw"))return false;// user is not logged in because we couldn't find session with username and/or password if(!$this->userExists($this->getSession("tysus"),$this->getSession("tyspw")))return false;// user is unknown to database return true;// other checks failed, user must be logged in } } ?>
And now I'm getting this error:
Fatal error: Call to undefined method users::readSetting() in /home/deb2371/domains/nonamenohistory.com/public_html/include/classes/class.database.php on line 18
What I thought would happen was something like this: Class users uses trait database and trait database would use trait settings and trait session.
If that was the case, I wouldn't get any errors, but unfortunately this isn't the case.
Does someone know how to fix this problem?