ExpressionManager (Flowable - Engine Common 6.8.1 API)

All Known Implementing Classes:

DefaultExpressionManager
```
public interface ExpressionManager
```
Used as an entry point for runtime evaluation of the expressions.

Author:

Tijs Rademakers, Joram Barrez

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Expression`	`createExpression(String expression)`	Creates an `Expression` instance from the given String.
`List<FlowableAstFunctionCreator>`	`getAstFunctionCreators()`	Returns the `FlowableAstFunctionCreator` which potentially can alter the expression functions during the creation of an `Expression` instance.
`Map<Object,Object>`	`getBeans()`	Returns the beans registered with this expression manager instance.
`ELContext`	`getElContext(VariableContainer variableContainer)`	Creates an `ELContext` against which `Expression` instance can be resolved.
`List<FlowableFunctionDelegate>`	`getFunctionDelegates()`	Returns the custom functions registered and usable in expressions.
`void`	`setAstFunctionCreators(List<FlowableAstFunctionCreator> astFunctionCreators)`	Sets the `FlowableAstFunctionCreator` instances which can alter the expression functions during the creation of an `Expression` instance.
`void`	`setBeans(Map<Object,Object> beans)`	Sets the beans which can be used in expressions.
`void`	`setFunctionDelegates(List<FlowableFunctionDelegate> functionDelegates)`	Set the custom functions usable in expressions.

- Method Detail
  - createExpression
```
Expression createExpression(String expression)
```
    Creates an Expression instance from the given String. Expression are resolved against a VariableContainer (e.g. a process Execution, a case instance plan item, etc.)
  - getElContext
```
ELContext getElContext(VariableContainer variableContainer)
```
    Creates an ELContext against which Expression instance can be resolved.
  - getBeans
```
Map<Object,Object> getBeans()
```
    Returns the beans registered with this expression manager instance.
  - setBeans
```
void setBeans(Map<Object,Object> beans)
```
    Sets the beans which can be used in expressions.
  - getFunctionDelegates
```
List<FlowableFunctionDelegate> getFunctionDelegates()
```
    Returns the custom functions registered and usable in expressions.
  - setFunctionDelegates
```
void setFunctionDelegates(List<FlowableFunctionDelegate> functionDelegates)
```
    Set the custom functions usable in expressions.
  - getAstFunctionCreators
```
List<FlowableAstFunctionCreator> getAstFunctionCreators()
```
    Returns the FlowableAstFunctionCreator which potentially can alter the expression functions during the creation of an Expression instance.
  - setAstFunctionCreators
```
void setAstFunctionCreators(List<FlowableAstFunctionCreator> astFunctionCreators)
```
    Sets the FlowableAstFunctionCreator instances which can alter the expression functions during the creation of an Expression instance.