JpqlFunction (Blazebit Persistence Core API 1.5.0-Alpha2 API)

```
public interface JpqlFunction
```
Interface for implementing a JPA custom function that renders dbms specific code. An instance of this interface needs to be registered to be able to use the function in queries.

Since:

1.0.0

Author:

Christian Beikov

See Also:

EntityManagerFactoryIntegrator.registerFunctions(javax.persistence.EntityManagerFactory, java.util.Map)

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Class<?>`	`getReturnType(Class<?> firstArgumentType)`	Returns the return type of this function.
`boolean`	`hasArguments()`	Returns true if the function has arguments, false otherwise.
`boolean`	`hasParenthesesIfNoArguments()`	Returns false if parentheses might be skipped if no arguments are given, true otherwise.
`void`	`render(FunctionRenderContext context)`	Renders the function into the given function render context.

- Method Detail
  - hasArguments
```
boolean hasArguments()
```
    Returns true if the function has arguments, false otherwise.
    
    Returns:
    
    true if the function has arguments, false otherwise
  - hasParenthesesIfNoArguments
```
boolean hasParenthesesIfNoArguments()
```
    Returns false if parentheses might be skipped if no arguments are given, true otherwise.
    
    Returns:
    
    false if parentheses might be skipped if no arguments are given, true otherwise
  - getReturnType
```
Class<?> getReturnType(Class<?> firstArgumentType)
```
    Returns the return type of this function. The return type may be null, but beware that nesting this function into other expressions may then fail.
    
    Parameters:
    
    firstArgumentType - The type of the first argument
    
    Returns:
    
    the return type of this function, or null
  - render
```
void render(FunctionRenderContext context)
```
    Renders the function into the given function render context.
    
    Parameters:
    
    context - The context into which the function should be rendered