# ConstructorStreamNamespacePredicateProvider Methods

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.streams.constructorstreamnamespacepredicateprovider/)

## FormatPattern(Type, string) {#formatpattern-system-type-string-8c877491}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.streams.constructorstreamnamespacepredicateprovider/methods/formatpattern-system-type-string-8c877491/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/PubSub/DefaultStreamNamespacePredicateProvider.cs#L48-L53)

```csharp
public static string FormatPattern(Type predicateType, string constructorArgument)
```

Formats a stream namespace predicate which indicates a concrete [IStreamNamespacePredicate](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.streams.istreamnamespacepredicate/) type to be constructed, along with an optional argument.

### Parameters

- `predicateType` (`Type`)
- `constructorArgument` (`string`)

## TryGetPredicate(string, IStreamNamespacePredicate) {#trygetpredicate-string-out-orleans-streams-istreamnamespacepredicate-c8372f70}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.streams.constructorstreamnamespacepredicateprovider/methods/trygetpredicate-string-out-orleans-streams-istreamnamespacepredicate-c8372f70/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/PubSub/DefaultStreamNamespacePredicateProvider.cs#L59-L96)

```csharp
public bool TryGetPredicate(string predicatePattern, out IStreamNamespacePredicate predicate)
```

Get the predicate matching the provided pattern. Returns `false` if this provider cannot match the predicate.

### Parameters

- `predicatePattern` (`string`)
- `predicate` (`IStreamNamespacePredicate`)