DBObject.php

<?php

abstract class DBObject {

    abstract static function getColumns();
    abstract static function getTableName();

    protected $db, $values, $inDB, $syncedToDB;

    function __construct($record=false,$fromDB=false) {
        $this->db = DBConnectionFactory::Instance();
        if ($record) {
            $this->setValues($record, $fromDB);
        }
    }

    static function getObjectById($id,$class) {
        $db = DBConnectionFactory::Instance();
        $empty_class = new $class();
        $values = [$empty_class->getPrimaryKey() => $id];
        $records = $db->select($empty_class->getTableName(),$values);
        $obj = false;
        if (count($records)>=1) {
            $obj = new $class($records[0],true);
        }
        return $obj;
    }

    protected function getColumnNames() {
        $names = [];
        foreach ($this->getColumns() as $column) {
            $names[] = $column['name'];
        }
        return $names;
    }

    protected function getPrimaryKey()
    {
        foreach ($this->getColumns() as $column) {
            if ($column['primary_key']) {
                return $column['name'];
            }
        }
        return false;
    }

    public function setValues($values,$fromDB) {
        $this->values = [];
        foreach($this->getColumnNames() as $column) {
            if (isset($values[$column])) {
                $this->values[$column] = $values[$column];
            } else {
                $this->values[$column] = null;
            }
        }
        $this->inDB = $fromDB;
        $this->syncedToDB = $fromDB;
    }

    private function check_column_names($values) {
        foreach($values as $key=>$val) {
            if (!in_array($key,$this->getColumnNames())) {
                return false;
            }
        }
        return true;
    }

    public function getValues($expandForeignRecords=false) {
        if ($expandForeignRecords) {
            foreach ($this->getColumns() as $column) {
                if (array_key_exists('foreign_key',$column) && !array_key_exists($column['name'].'_values',$this->values)) {
                    $foreign_obj = $column['foreign_table']::getObjectById($this->getValue($column['name']),$column['foreign_table']);
                    // This will break with circular references!!!
                    if ($foreign_obj) {
                        $this->values[$column['name'] . '_values'] = $foreign_obj->getValues(true);
                    }
                }
            }
        }
        return $this->values;
    }

    public function getValue($column) {
        if (isset($this->values[$column])) {
            return $this->values[$column];
        } else if (in_array($column,$this->getColumnNames())) {
            return null;
        } else {
            return false;
        }
    }

    public function setValue($column,$value,$syncToDB=false) {
        if (in_array($column,$this->getColumnNames())) {
            $this->values[$column] = $value;
            $this->syncedToDB = false;
        }
        if ($syncToDB) {
            $this->updateDB();
        }
    }

    public function saveToDB($skipUpdate=false) {
        $primarykey = $this->getPrimaryKey();
        if ($this->inDB) {
            if (!$this->syncedToDB) {
                return $this->updateDB();
            }
        } else if ($this->getValue($primarykey)==null) {
            //error_log('Inserting into DB: '.json_encode($this->getValues()));
            return $this->insertIntoDB($skipUpdate);
        }
    }

    protected function insertIntoDB($skipUpdate=false) {
        if ($this->check_column_names($this->values)) {
            $this->db->insert($this->getTableName(),$this->values);
            $last_id = $this->db->lastInsertId();
            $primary_key = $this->getPrimaryKey();
            $this->setValue($primary_key,$last_id);
            if (!$skipUpdate===true) {
                $records = $this->db->select($this->getTableName(),[$primary_key => $last_id]);
                if (count($records)==1) {
                    $this->setValues($records[0],true);
                    return true;
                } else {
                    error_log('Object not inserted into DB! LastID: '.$last_id);
                }
            }
            return true;
        } else {
            error_log('Column names not set correctly in DBObject');
        }
        return false;
    }

    protected function updateDB() {
        $primarykey = $this->getPrimaryKey();
        if ($this->check_column_names($this->values) && $this->getValue($primarykey)) {
            $primary = ['key'=>$primarykey, 'value'=>$this->getValue($primarykey)];
            $this->db->update($this->getTableName(),$primary,$this->values);
            $this->syncedToDB = true;
        }
        return $this->syncedToDB;
    }
}