IOption (argparse4j 1.3.0 API)

```
public interface IOption
```
IOption is the interface that should be implemented by enums that contain global options. The methods required to implement this interface are required to configure the options with argparse4j. Moreover, this interface contains a bunch of default implementations that are made up of the methods that need to be implemented manually.

Author:

Tobias Neitzel (@qtc_de)

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`default void`	`addModifiers(Argument arg)` IOption can have associated IArgumentModifiers that modify different properties of the option in the context of argparse4j (e.g.
`default void`	`addOption(ArgumentParser parser, IAction action)` Add the option to an argument parser.
`ArgumentAction`	`getArgumentAction()` Get the associated `ArgumentAction` to an option.
`IArgumentModifier[]`	`getArgumentModifiers()` Get the associated `IArgumentModifier` to an option.
`default <T> boolean`	`getBool()` Check whether an boolean option is true or false.
`String`	`getDescription()` Get the description of an option.
`String`	`getEnumName()` Returns the name of the enum entry that represents the option.
`default IOptionGroup`	`getGroup()` Get the group associated with an option.
`String`	`getName()` Get the name of an option as it is supposed to be represented on a command line.
`default String`	`getPlainName()` Returns the option name with all leading dashes being removed.
`default Class<?>`	`getType()` Return the underlying Java type of an option.
`<T> T`	`getValue()` Get the value of an option.
`default boolean`	`isNull()` Return true if the value associated with the option is null.
`default boolean`	`notNull()` Return true if the value associated with the option is not null.
`default <T> T`	`require()` Require an option at runtime.
`static void`	`requireAllOf(IOption... options)` Require that each of the specified options has an value assigned.
`static <T> T`	`requireOneOf(IOption... options)` Require an option or one of the other specified options at runtime.
`default <T> void`	`setValue(Namespace args, T def)` Set an option value according to the user specified command line.
`<T> void`	`setValue(T value)` Set the value of an option.
`default <T> void`	`setValue(T value, T def)` Set the option value to the specified value or to the specified default, if the value is null.

- Method Detail
  - getName
```
String getName()
```
    Get the name of an option as it is supposed to be represented on a command line.
    
    Returns:
    
    the name of an option
  - getDescription
```
String getDescription()
```
    Get the description of an option.
    
    Returns:
    
    the description of an option
  - getArgumentAction
```
ArgumentAction getArgumentAction()
```
    Get the associated ArgumentAction to an option.
    
    Returns:
    
    the associated ArgumentAction
  - getArgumentModifiers
```
IArgumentModifier[] getArgumentModifiers()
```
    Get the associated IArgumentModifier to an option.
    
    Returns:
    
    the associated IArgumentModifier as array
  - setValue
```
<T> void setValue(T value)
```
    Set the value of an option. IOption implementations are intended to be enums. Since the interface does not have access to the enum members, implementors need to implement the setValue method on their own.
    
    Type Parameters:
    
    T - the type of the value that is set
    
    Parameters:
    
    value - the value that is set
  - getValue
```
<T> T getValue()
```
    Get the value of an option. IOption implementations are intended to be enums. Since the interface does not have access to the enum members, implementors need to implement the getValue method on their own.
    
    Type Parameters:
    
    T - the type of the options value
    
    Returns:
    
    the options value
  - getEnumName
```
String getEnumName()
```
    Returns the name of the enum entry that represents the option. This is useful to uniquely identify an option.
    
    Returns:
    
    enum entry name of the current option.
  - getPlainName
```
default String getPlainName()
```
    Returns the option name with all leading dashes being removed. Other dashes are replaced by underscores.
    
    Returns:
    
    plain option name
  - getGroup
```
default IOptionGroup getGroup()
```
    Get the group associated with an option. By default, options do not have groups assigned and the functions returns zero. IOptionGroups are intended to be stored within the enum that implements IOption. Therefore, implementors need to re-implement this method on their own to get something useful done.
    
    Returns:
    
    the IOptionGroup associated to an option
  - isNull
```
default boolean isNull()
```
    Return true if the value associated with the option is null. This usually indicates that the corresponding option was not used on the command line.
    
    Returns:
    
    true if the value of the option is null
  - notNull
```
default boolean notNull()
```
    Return true if the value associated with the option is not null. This usually indicates that the corresponding option was used on the command line.
    
    Returns:
    
    true if the value of the option is not null
  - getBool
```
default <T> boolean getBool()
```
    Check whether an boolean option is true or false.
    
    Returns:
    
    true if boolean option is true
  - setValue
```
default <T> void setValue(T value,
                          T def)
```
    Set the option value to the specified value or to the specified default, if the value is null.
    
    Type Parameters:
    
    T - the type of the value
    
    Parameters:
    
    value - the specified value
    
    def - the specified default
  - setValue
```
default <T> void setValue(Namespace args,
                          T def)
```
    Set an option value according to the user specified command line.
    
    Type Parameters:
    
    T - the type of the value
    
    Parameters:
    
    args - the user specified command line
    
    def - the specified default
  - getType
```
default Class<?> getType()
```
    Return the underlying Java type of an option. If the argumentAction is StoreTrue, the type is always considered boolean. Otherwise, the type of an IOption can be represented by an IArgumentModifier. The corresponding modifier is named Type and can be used to indicate the class of the option. This function iterates over all modifiers and returns the value of the Type modifier if present. If no Type modifier is present, it is assumed that the argument type is String.
    
    Returns:
    
    the class that is associated with the option (default is String for store or boolean for storeTrue arguments)
  - addOption
```
default void addOption(ArgumentParser parser,
                       IAction action)
```
    Add the option to an argument parser.
    
    Parameters:
    
    parser - the parser to add the option to
    
    action - the action that is associated with the option (can be null)
  - addModifiers
```
default void addModifiers(Argument arg)
```
    IOption can have associated IArgumentModifiers that modify different properties of the option in the context of argparse4j (e.g. nargs, choices, argument type, etc.). This function applies the configured modifiers to an argument. This function is called within the addOption function and should usually not be used manually.
    
    Parameters:
    
    arg - the argument to apply the modifiers to
  - require
```
default <T> T require()
               throws RequirementException
```
    Require an option at runtime. If the corresponding option was not set, an RequirementFailedException is thrown.
    
    Type Parameters:
    
    T - type of the option
    
    Returns:
    
    the value that is assigned to the option (if any)
    
    Throws:
    
    RequirementException - is raised if no value was set for this option
  - requireOneOf
```
static <T> T requireOneOf(IOption... options)
                   throws RequirementException
```
    Require an option or one of the other specified options at runtime. The function returns the value of the first option that was set, or raises an RequirementFailedException if none of the options was set.
    
    Type Parameters:
    
    T - type of the option
    
    Parameters:
    
    options - list of additional options to require
    
    Returns:
    
    the value that is assigned to one of the option (if any)
    
    Throws:
    
    RequirementException - is raised if all options have no value assigned
  - requireAllOf
```
static void requireAllOf(IOption... options)
                  throws RequirementException
```
    Require that each of the specified options has an value assigned. If this is not true, an RequirementFailedException is thrown.
    
    Parameters:
    
    options - list of additional options to require
    
    Throws:
    
    RequirementException - is raised if at least one option has no value assigned

Interface IOption

Method Summary

Method Detail

getName

getDescription

getArgumentAction

getArgumentModifiers

setValue

getValue

getEnumName

getPlainName

getGroup

isNull

notNull

getBool

setValue

setValue

getType

addOption

addModifiers

require

requireOneOf

requireAllOf