genericobject.phpm

Professional PHP5 code for this book

<?
class GenericObject {

  # Member Variables

  private $id;
  private $table_name;
  
  private $database_fields;
  private $loaded;          
  private $modified_fields
  
  # Methods

  public function Reload() {           
    $sql = new sql(0);
    $id = $this->id;
    $table_name = $this->table_name;
    $sql->query("SELECT * FROM \"$table_name\" WHERE id='$id'");
    $result_fields = $sql->get_row_hash(0);
    $this->database_fields = $result_fields;
    $this->loaded = 1;
    if (sizeof($this->modified_fields) > 0) {
      foreach ($this->modified_fields as $key => $value) {
        $this->modified_fields[$key] = false;
      };
    };
  }
  
  private function Load() {
    $this->Reload();
    $this->loaded = 1;
  }
  
  public function ForceLoaded() {
    $this->loaded = 1;
  }
    
  public function GetField($field) {          
    if ($this->loaded == 0) {
      $this->Load();            
    };
    return $this->database_fields[$field];
  }
  
  public function GetAllFields() {
    if ($this->loaded == 0) {
      $this->Load();            
    };  
    return($this->database_fields);
  }
  
  public function GetID() {
    return $this->id;
  }

  public function Initialize($table_name, $tuple_id = "") {
    $this->table_name = $table_name;
    $this->id = $tuple_id;
  }

  public function SetField($field, $value) {    
    if ($this->loaded == 0) {
      if ($this->id) {
        $this->Load();            
      };
    };
    $this->database_fields[$field] = $value;
    $this->modified = 1;
    $this->modified_fields[$field] = true;
  }  
  
  public function Destroy() {
    $id = $this->id;
    $table_name = $this->table_name;
    if ($id) {
      $sql = new sql(0);
      $stmt = "DELETE FROM \"" . $table_name . "\" WHERE id='" . $id . "'";
      $sql->query($stmt);
    };
  }
  
  public function Save() {
    $id = $this->id;
    $table_name = $this->table_name;
    $sql = new sql(0);
    if (!$id) {
      $this->loaded = 0;
    };
    if ($this->loaded == 0) {
      # assume this is a new entity
      $stmt = "INSERT INTO \"" . $table_name ."\"(";
      foreach ($this->database_fields as $key => $value) {
        if (!is_numeric($key)) {
          $key = str_replace("'", "\'", $key);
          if ($value != "") {
            $stmt .= "\"$key\",";
          };
        };
      };
      # Chop last comma
      $stmt = substr($stmt,0,strlen($stmt)-1);
      $stmt .= ") VALUES (";
      foreach ($this->database_fields as $key => $value) {
        if (!is_numeric($key)) {
          if ($value != "") {
            $value = str_replace("'", "\'", $value);
            $stmt .= "'$value',";
          };
        };
      };
      # Chop last comma
      $stmt = substr($stmt,0,strlen($stmt)-1);
      $stmt .= ")";      
    } else {
      $stmt = "UPDATE \"" . $table_name ."\" SET ";
      foreach ($this->database_fields as $key => $value) {
        if (!is_numeric($key)) {
          if ($this->modified_fields[$key] == true) {
            $value = str_replace("'", "\'", $value);
            if ($value == "") {
              $stmt .= "\"$key\" = NULL, ";
            } else {
              $stmt .= "\"$key\" = '$value', ";
            };
          };
        };
      };
      # Chop last comma and space
      $stmt = substr($stmt,0,strlen($stmt)-2);
      $stmt .= " WHERE id='$id'";
    };
    $return_code = $sql->query($stmt, 1);    
    if ($this->loaded == 0) {
      # Try to get the ID of the new tuple.
      $stmt = "SELECT MAX(id) AS id FROM \"$table_name\" WHERE ";
      foreach ($this->database_fields as $key => $value) {
        if (!is_numeric($key)) {
          if ($value) {
            if ($this->modified_fields[$key] == true) {
              $value = str_replace("'", "\'", $value);
              $stmt .= "\"$key\" = '$value' AND ";
            };
          };
        };
      };      
      # Chop last " AND " (superfluous)
      $stmt = substr($stmt,0,strlen($stmt)-5);
      $sql->query($stmt);
      $result_rows = $sql->get_table_hash();
      $proposed_id = $result_rows[0]["id"];
      if ($proposed_id > 0) {
        $this->loaded = 1;
        $this->id = $proposed_id;
        return true;
      } else {
        return false;
      };
    };
    return($return_code);
  }
};