### Constructor

# Gtk PropertyExpression new

#### Declaration [src]

    GtkExpression*
    gtk_property_expression_new (
      GType this_type,
      GtkExpression* expression,
      const char* property_name
    )

#### Description [src]

Creates an expression that looks up a property.

The object to use is found by evaluating the `expression`, or using the `this` argument when `expression` is `NULL`.

If the resulting object conforms to `this_type`, its property named `property_name` will be queried. Otherwise, this expression’s evaluation will fail.

The given `this_type` must have a property with `property_name`.

#### Parameters

`this_type`

  Type: `GType`

  The type to expect for the this type.

`expression`

  Type: `GtkExpression`

  Expression to evaluate to get the object to query or `NULL` to query the `this` object.

  The argument can be `NULL`.
  The called function takes ownership of the data, and is responsible for freeing it.

`property_name`

  Type: `const char*`

  Name of the property.

  The data is owned by the caller of the function.
  The value is a NUL terminated UTF-8 string.

#### Return value

Type: `GtkPropertyExpression`

A new `GtkExpression`.

The caller of the function takes ownership of the data, and is responsible for freeing it.