function __construct($expression)
{
if (Expression::isCompositeBinding($expression)) {
throw new DataBindingException("Multiple binding expressions on a string are not supported: <kbd>{$expression}</kbd>\n<p>Convert it to a single expression using the <kbd>+</kbd> string concatenation operator.");
}
if (!preg_match(self::$PARSE_BINDING_EXP, $expression, $matches)) {
throw new DataBindingException("Invalid databinding expression: {$expression}");
}
list($full, $this->expression) = $matches;
}
