Basing models off the DataObject Class

DataObject.class.php

<?php
//error_reporting(-1);
//ini_set('display_errors', 'On');

// config.php contents:
//define("DB_DSN", "mysql:dbname=database");
//define("DB_USERNAME", "username");
//define("DB_PASSWORD", "password!");



require_once "config.php";

abstract class DataObject {

  protected $data = array();
  protected $errors = array();
  
  public function __construct( $data ) {
    foreach ( $data as $key => $value ) {
      if ( array_key_exists( $key, $this->data ) ) $this->data[$key] = $value;
    }
  }

  public function getValue( $field ) {
    if ( array_key_exists( $field, $this->data ) ) {
      return $this->data[$field];
    } else {
      die( "Field not found: " . $field);
    }
  }

  public function setValue( $field, $value ) {
    if ( array_key_exists( $field, $this->data ) ) {
        $this->data[$field] = $value;
    } else {
      die( "Field not found: " . $field);
    }
  }
  
  public function getValueEncoded( $field ) {
    return htmlspecialchars( $this->getValue( $field ) );
  }

  protected function connect() {
    try {
      $conn = new PDO( DB_DSN, DB_USERNAME, DB_PASSWORD );
      $conn->setAttribute( PDO::ATTR_PERSISTENT, true );
      $conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
    } catch ( PDOException $e ) {
      die( "Connection failed: " . $e->getMessage() );
    }

    return $conn;
  }

  protected function disconnect( $conn ) {
    $conn = "";
  }
}

?>

posts.class.php

<?php
require_once "DataObject.class.php";

class Post extends DataObject
{
    
    protected $table_name = "posts";

    var $data = array(
        "id" => "",
        "blogpost" => "",
        "upload" => "",
        "createdate" => "",
        "userid" => "",
        "title" => "",
        "tags" => ""
    );

    public function __construct(array $args=[])
    {
        $this->$data["id"] = "";
        $this->$data["blogpost"] = "";
        $this->$data["upload"] = "";
        $this->$data["createdate"] = "";
        $this->$data["userid"] = "";
        $this->$data["title"] = "";
        $this->$data["tags"] = "";

        if ($args){
            foreach ($arr as $key => $value){
                $this->$data[$key] = $value;
            }
        }
    }

    public function getPost($id)
    {
        $conn = parent::connect();
        $sql = "SELECT * FROM posts WHERE id = :id";

        try
        {
            $st = $conn->prepare($sql);
            $st->bindValue(":id", $id, PDO::PARAM_STR);
            $st->execute();
            $row = $st->fetch();
            parent::disconnect($conn);
            if ($row)
            {
                $this->setValue("id", $row['id']);
                $this->setValue("blogpost", $row['blogpost']);
                $this->setValue("upload", $row['upload']);
                $this->setValue("createdate", $row['createdate']);
                $this->setValue("userid", $row['userid']);
                $this->setValue("title", $row['title']);
                $this->setValue("tags", $row['tags']);
                return $this;
            }
            else
            {
                return false;
            }

        }
        catch(PDOException $e)
        {
            parent::disconnect($conn);
            die("Query failed: " . $e->getMessage());
        }
    } //end getUser
    

    public static function getAllPosts($limit1, $limit2)
    {
        if(!isset($limit1)){
            //show this many
            $limit1 = "10";
        }
        
        if(!isset($limit2)){
            // start from this record
            $limit2 = "0";
        }

        $conn = parent::connect();
        $sql = "SELECT * FROM posts ORDER BY id DESC";

        try
        {
            $st = $conn->prepare($sql);
            //$st->bindValue(":limit1", $limit1, PDO::PARAM_STR);
            //$st->bindValue(":limit2", $limit2, PDO::PARAM_STR);
            $st->execute();
            $results = $st->fetchAll();
            parent::disconnect($conn);
            if ($results)
            {
                return $results;
            }
            else
            {
                return false;
            }

        }
        catch(PDOException $e)
        {
            parent::disconnect($conn);
            error_log("Query failed: " . $e->getMessage());
            return false;
        }
    } //end getUser
    

        public static function savePost($blogpost, $title, $tags)
        {
            if (!isset($blogpost)){
                error_log("Blogpost wasnt set when passed to savePost");
            }
            
            if (!isset($title)){
                error_log("Title wasnt set when passed to savePost");
            }
            
            if (!isset($tags)){
                error_log("Tags wasnt set when passed to savePost");
            }
            
            $conn = parent::connect();
            $sql = "INSERT INTO posts (blogpost, title, tags) VALUES (:blogpost, :title, :tags)";
            // Assume that we are using the other methods in this class to build this query
            try
            {
                $st = $conn->prepare($sql);
                $st->bindValue(":blogpost", $blogpost);
                $st->bindValue(":title", $title);
                $st->bindValue(":tags", $tags);
                $st->execute();
                $id = strval($conn->lastInsertId());
                return $id;
            } //end try for user/email
            catch(PDOException $e)
            {
                    parent::disconnect($conn);
                    //error_log($e->getMessage());
                    error_log("Query failed: " . $e->getMessage());
                    return 0;
                } //end catch for user/email
                
            } //end login
            
        } //end class
        
?>