goog.string.Const.from
is only invoked on
compile-time-constant expressions.
Const is useful in APIs whose correct and secure use requires that certain
arguments are not attacker controlled: Compile-time constants are inherently
under the control of the application and not under control of external
attackers, and hence are safe to use in such contexts.
Instances of this type must be created via its factory method
goog.string.Const.from
and not by invoking its constructor. The
constructor intentionally takes no parameters and the type is immutable;
hence only a default instance corresponding to the empty string can be
obtained via constructor invocation.
Utility method to create Const instances.
Arguments:
Returns: !goog.string.Const
The initialized Const object.
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Creates a Const object from a compile-time constant string.
It is illegal to invoke this function on an expression whose
compile-time-contant value cannot be determined by the Closure compiler.
Correct invocations include,
var s = goog.string.Const.from('hello'); var t = goog.string.Const.from('hello' + 'world');In contrast, the following are illegal: var s = goog.string.Const.from(getHello()); var t = goog.string.Const.from('hello' + world);TODO(user): Compile-time checks that this function is only called with compile-time constant expressions.
Arguments:
Returns: !goog.string.Const
A Const object initialized to stringConst.
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Performs a runtime check that the provided object is indeed an instance
of
goog.string.Const , and returns its value.
Arguments:
Returns: string
The Const object's contained string, unless the run-time
type check fails. In that case,
unwrap returns an innocuous
string, or, if assertions are enabled, throws
goog.asserts.AssertionError .
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