framework/db/BaseActiveRecord.php
public function setAttribute($name, $value)
    {
        if ($this->hasAttribute($name)) {
            if (
                !empty($this->_relationsDependencies[$name])
                && (!array_key_exists($name, $this->_attributes) || $this->_attributes[$name] !== $value)
            ) {
                $this->resetDependentRelations($name);
            }
            $this->_attributes[$name] = $value;
        } else {
            throw new InvalidArgumentException(get_class($this) . ' has no attribute named "' . $name . '".');
        }
    }
public function setAttribute($name, $value)
    {
        if ($this->hasAttribute($name)) {
            if (
                !empty($this->_relationsDependencies[$name])
                && (!array_key_exists($name, $this->_attributes) || $this->_attributes[$name] !== $value)
            ) {
                $this->resetDependentRelations($name);
            }
            $this->_attributes[$name] = $value;
        } else {
            throw new InvalidArgumentException(get_class($this) . ' has no attribute named "' . $name . '".');
        }
    }
Sets the named attribute value.
@param string $name the attribute name
@param mixed $value the attribute value.
@throws InvalidArgumentException if the named attribute does not exist.
@see hasAttribute()