<?php
  class JSONVahetaja implements Andmevahetaja{
     private $andmed=array();
     private $failinimi;
     function __construct($failinimi){
        $this->failinimi=$failinimi;
        $this->loe();
     }
     function tyhjenda(){$this->andmed=array();}
     function lisa(Andmeliides $obj){
       array_push($this->andmed, $obj);
       $this->salvesta();
     }
     private function salvesta(){
        $abi=array();
        foreach($this->andmed as $teade){
          $obj=new Stdclass();
          $obj->pealkiri=$teade->kysiPealkiri();
          $obj->sisu=$teade->kysiSisu();
          array_push($abi, $obj);
        }
        file_put_contents($this->failinimi, json_encode($abi));
     }
     private function loe(){
        if(file_exists($this->failinimi)){
          $abi=json_decode(file_get_contents($this->failinimi));
          $this->andmed=array();
          foreach($abi as $teade){
             array_push($this->andmed, 
               new Andmeobjekt($teade->pealkiri, $teade->sisu));
          }
        }
     }
     function kysiAndmeLiidesed(){
       return $this->andmed;
     } 
     //Koosta lihtne demofail paari kirje lisamise ja vaatamisega
  }