# Class Extensions

OptimaJet.Workflow.Core.Extensions

Provides extension methods used by core workflow engine components.

Namespace: [OptimaJet.Workflow.Core](https://api.workflowengine.io/core/OptimaJet.Workflow.Core/)

```csharp
public static class Extensions
```

## Methods

`public static XElement SingleOrDefault(this XElement element, string name)` 

Gets the current [XElement](https://learn.microsoft.com/dotnet/api/system.xml.linq.xelement) when its name matches; otherwise, gets the only direct child with the requested name.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `element` | `XElement` | The source XML element. |
| `name` | `String` | The XML name to match. |

### Returns

| Type | Description |
| --- | --- |
| `XElement` | The current element when its name equals `name`, the only matching direct child element with that name, or [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null) when none is found. |

### Exceptions

| Type | Description |
| --- | --- |
| `InvalidOperationException` | More than one direct child has the requested name. |

`public static Type ToNullableType(this Type type)` 

Gets a nullable equivalent for value types.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `type` | `Type` | The source type. |

### Returns

| Type | Description |
| --- | --- |
| `Type` | The corresponding [Nullable<T>](https://learn.microsoft.com/dotnet/api/system.nullable-1) type for a value type, the original nullable type when `type` is already nullable, or the original type for a reference type. |

`public static bool IsNullable(this Type type)` 

Determines whether a type is a nullable value type.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `type` | `Type` | The type to inspect. |

### Returns

| Type | Description |
| --- | --- |
| `Boolean` | [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool) when `type` is constructed from [Nullable<T>](https://learn.microsoft.com/dotnet/api/system.nullable-1); otherwise [false](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool). |

`public static Type GetUnderlyingType(this Type type)` 

Gets the non-nullable underlying type for a nullable type.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `type` | `Type` | The type to inspect. |

### Returns

| Type | Description |
| --- | --- |
| `Type` | The underlying type argument for [Nullable<T>](https://learn.microsoft.com/dotnet/api/system.nullable-1) values, or the original type when the value is not nullable. |

`public static object GetDefaultValue(this Type type)` 

Gets the default value for a type.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `type` | `Type` | The type whose default value to create. |

### Returns

| Type | Description |
| --- | --- |
| `Object` | The zero-initialized value for value types, or [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null) for reference types. |

`public static bool IsNumeric(this Type type)` 

Determines whether the type is one of the numeric types recognized by the engine.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `type` | `Type` | The type to check. |

### Returns

| Type | Description |
| --- | --- |
| `Boolean` | [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool) when `type` is exactly one of the supported numeric types; otherwise [false](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool). |

`public static string ToLowerCaseString(this bool value)` 

Returns the [bool](https://learn.microsoft.com/dotnet/api/system.boolean) value as lower-case text.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `value` | `Boolean` | The value to convert. |

### Returns

| Type | Description |
| --- | --- |
| `String` | `true` as `true` and `false` as `false`. |

`public static bool ExtendedEquals(this object value, object valueToCompare)` 

Compares two values with an extended rule for enumerable types.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `value` | `Object` | The value to compare. |
| `valueToCompare` | `Object` | The value to compare against. |

### Returns

| Type | Description |
| --- | --- |
| `Boolean` | [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool) when the values are equal by this method's comparison rules; otherwise [false](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool). |

### Remarks

When both values are non-null, have the same runtime type, and implement [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.ienumerable), comparison is performed element-by-element by index.

`public static string ToFormattedString<T>(this List<T> value, bool quotate)` 

Converts a list into a delimited string, using a comma as the separator.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `value` | `List<T>` | The list to serialize. |
| `quotate` | `Boolean` | Whether each item should be wrapped in single quotes. |

### Returns

| Type | Description |
| --- | --- |
| `String` | The formatted string representation. |

`public static string ToFormattedString<T>(this List<T> value, string delimeter, bool quotate)` 

Converts a list into a delimited string.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `value` | `List<T>` | The list to serialize. |
| `delimeter` | `String` | The delimiter to place between list items. |
| `quotate` | `Boolean` | Whether each item should be wrapped in single quotes. |

### Returns

| Type | Description |
| --- | --- |
| `String` | The formatted string representation. |

`public static bool TryGetValueIgnoreCase<TV>(this IDictionary<string, TV> dictionary, string key, out TV value)` 

Tries to get a value from a dictionary using a case-insensitive key match.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `dictionary` | `IDictionary<String, TV>` | The dictionary to query. |
| `key` | `String` | The key to match in a case-insensitive manner. |
| `value` | `{TV}` | When the method returns [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool), contains the matching value; otherwise the default value. |

### Returns

| Type | Description |
| --- | --- |
| `Boolean` | [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool) when exactly one key matches `key` ignoring case; otherwise [false](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool). |

`public static dynamic ToDynamic(this Dictionary<string, object> dictionary)` 

Creates a dynamic object from a string/object dictionary.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `dictionary` | `Dictionary<String, Object>` | The source dictionary. |

### Returns

| Type | Description |
| --- | --- |
| `dynamic` | An [ExpandoObject](https://learn.microsoft.com/dotnet/api/system.dynamic.expandoobject) containing all dictionary entries. |

`public static string ToValidCSharpIdentifierName(this string originalString)` 

Converts non-empty text to an identifier-compatible string by replacing unsupported characters and adding a leading underscore when required.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `originalString` | `String` | The non-null, non-empty source text. |

### Returns

| Type | Description |
| --- | --- |
| `String` | A sanitized identifier-compatible string. C# keywords are not escaped. |

### Exceptions

| Type | Description |
| --- | --- |
| `ArgumentNullException` | `originalString` is [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null). |
| `ArgumentOutOfRangeException` | `originalString` is empty. |

`public static T? FirstOrNull<T>(this IEnumerable<T> items, Func<T, bool> predicate) where T : struct` 

Returns the first element that matches a predicate, or [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null) when no elements match.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `items` | `IEnumerable<T>` | The sequence to search. |
| `predicate` | `Func<T, Boolean>` | The predicate used to test each element. |

### Returns

| Type | Description |
| --- | --- |
| `Nullable<T>` | A nullable `T` value for the first matching element, or [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null). |

### Exceptions

| Type | Description |
| --- | --- |
| `ArgumentNullException` | Thrown when `items` or `predicate` is [null](https://learn.microsoft.com/dotnet/csharp/language-reference/keywords/null). |

`public static bool IsSimpleDynamicType(this Type type)` 

Determines whether a type is considered a simple type for dynamic bindings.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `type` | `Type` | The type to inspect. |

### Returns

| Type | Description |
| --- | --- |
| `Boolean` | [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool) when the type is a primitive type or one of the supported additional simple types; otherwise [false](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool). |

`public static T CastAs<T>(this object obj)` 

Casts an object to the requested type when the runtime type is assignable.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `obj` | `Object` | The source object. |

### Returns

| Type | Description |
| --- | --- |
| `{T}` | The object cast to `T` when valid, otherwise the default value of `T`. |

`public static bool TryCast<T>(this object obj, out T newValue)` 

Tries to cast an object to a requested type.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `obj` | `Object` | The source object. |
| `newValue` | `{T}` | When the method returns [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool), the casted value; otherwise default. |

### Returns

| Type | Description |
| --- | --- |
| `Boolean` | [true](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool) when the cast succeeds; otherwise [false](https://learn.microsoft.com/dotnet/csharp/language-reference/builtin-types/bool). |

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