Interface IGetContextValueOptions

Inherited Members
Namespace: Amazon.CDK
Assembly: Amazon.CDK.Lib.dll
Syntax (csharp)
public interface IGetContextValueOptions : IGetContextKeyOptions
Syntax (vb)
Public Interface IGetContextValueOptions
    Inherits IGetContextKeyOptions
Remarks

ExampleMetadata: fixture=_generated

Examples
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
using Amazon.CDK;

var dummyValue;
var props;

var getContextValueOptions = new GetContextValueOptions {
    DummyValue = dummyValue,
    Provider = "provider",

    // the properties below are optional
    IgnoreErrorOnMissingContext = false,
    IncludeEnvironment = false,
    MustExist = false,
    Props = new Dictionary<string, object> {
        { "propsKey", props }
    }
};

Synopsis

Properties

DummyValue

The value to return if the lookup has not yet been performed.
IgnoreErrorOnMissingContext

(deprecated) Ignore a lookup failure and return the dummyValue instead.
MustExist

Whether the resource must exist.

Properties

DummyValue

The value to return if the lookup has not yet been performed.

object DummyValue { get; }
Property Value

System.Object

Remarks

Upon first synthesis, the lookups has not yet been performed. The getValue() operation returns this value instead, so that synthesis can proceed. After synthesis completes the first time, the actual lookup will be performed and synthesis will run again with the real value.

Dummy values should preferably have valid shapes so that downstream consumers of lookup values don't throw validation exceptions if they encounter a dummy value (or all possible downstream consumers need to effectively check for the well-known shape of the dummy value); throwing an exception would error out the synthesis operation and prevent the lookup and the second, real, synthesis from happening.

Connection to mustExist

dummyValue is also used as the official value to return if the lookup has failed and mustExist == false.

IgnoreErrorOnMissingContext

(deprecated) Ignore a lookup failure and return the dummyValue instead.

virtual Nullable<bool> IgnoreErrorOnMissingContext { get; }
Property Value

System.Nullable<System.Boolean>

Remarks

mustExist is the recommended alias for this deprecated property (note that its value is reversed).

Default: false

Stability: Deprecated

MustExist

Whether the resource must exist.

virtual Nullable<bool> MustExist { get; }
Property Value

System.Nullable<System.Boolean>

Remarks

If this is set (the default), the query fails if the value or resource we tried to look up doesn't exist.

If this is false and the value we tried to look up could not be found, the failure is suppressed and dummyValue is officially returned instead.

When this happens, dummyValue is encoded into cached context and it will never be refreshed anymore until the user runs cdk context --reset <key>.

Note that it is not possible for the CDK app code to make a distinction between "the lookup has not been performed yet" and "the lookup didn't find anything and we returned a default value instead".

Context providers

This feature must explicitly be supported by context providers. It is currently supported by:

    Note to implementors

    The dummy value should not be returned for all SDK lookup failures. For example, "no network" or "no credentials" or "malformed query" should not lead to the dummy value being returned. Only the case of "no such resource" should.

    Default: true