Package io.deephaven.engine.context

Class EmptyQueryScope

java.lang.Object

io.deephaven.engine.context.QueryScope

io.deephaven.engine.context.EmptyQueryScope

All Implemented Interfaces:

LogOutputAppendable

public class EmptyQueryScope
extends QueryScope

Nested Class Summary

Nested classes/interfaces inherited from class io.deephaven.engine.context.QueryScope

QueryScope.MissingVariableException, QueryScope.StandaloneImpl

Field Summary

Fields

Modifier and Type	Field	Description
static final EmptyQueryScope	INSTANCE

Method Summary

Modifier and Type	Method	Description
protected <T> QueryScopeParam<T>	createParam(String name)	Get a QueryScopeParam by name.
Set<String>	getParamNames()	Get all known scope variable names.
boolean	hasParamName(String name)	Check if the scope has the given name.
void	putObjectFields(Object object)	Add an object's public members (referenced reflectively, not a shallow copy!) to this scope if supported.
<T> void	putParam(String name, T value)	Add a parameter to the scope.
<T> T	readParamValue(String name)	Get the value of a given scope parameter by name.
<T> T	readParamValue(String name, T defaultValue)	Get the value of a given scope parameter by name.

Methods inherited from class io.deephaven.engine.context.QueryScope

addObjectFields, addParam, append, getParams, getParamValue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

INSTANCE

public static final EmptyQueryScope INSTANCE

Method Details

getParamNames

public Set<String> getParamNames()

Description copied from class: QueryScope

Get all known scope variable names.

Specified by:

getParamNames in class QueryScope

Returns:

A collection of scope variable names.

hasParamName

public boolean hasParamName(String name)

Description copied from class: QueryScope

Check if the scope has the given name.

Specified by:

hasParamName in class QueryScope

Parameters:

name - param name

Returns:

True iff the scope has the given param name

createParam

protected <T> QueryScopeParam<T> createParam(String name)
                                      throws QueryScope.MissingVariableException

Description copied from class: QueryScope

Get a QueryScopeParam by name.

Specified by:

createParam in class QueryScope

Parameters:

name - parameter name

Returns:

newly-constructed QueryScopeParam (name + value-snapshot pair).

Throws:

QueryScope.MissingVariableException - If any of the named scope variables does not exist.

readParamValue

public <T> T readParamValue(String name)
                     throws QueryScope.MissingVariableException

Description copied from class: QueryScope

Get the value of a given scope parameter by name.

Specified by:

readParamValue in class QueryScope

Parameters:

name - parameter name.

Returns:

parameter value.

Throws:

QueryScope.MissingVariableException - If no such scope parameter exists.

readParamValue

public <T> T readParamValue(String name,
 T defaultValue)

Description copied from class: QueryScope

Get the value of a given scope parameter by name.

Specified by:

readParamValue in class QueryScope

Parameters:

name - parameter name.

defaultValue - default parameter value.

Returns:

parameter value, or the default parameter value, if the value is not present.

putParam

public <T> void putParam(String name,
 T value)

Description copied from class: QueryScope

Add a parameter to the scope.

Specified by:

putParam in class QueryScope

Parameters:

name - parameter name.

value - parameter value.

putObjectFields

public void putObjectFields(Object object)

Description copied from class: QueryScope

Add an object's public members (referenced reflectively, not a shallow copy!) to this scope if supported. Note: This is an optional method.

Specified by:

putObjectFields in class QueryScope

Parameters:

object - object to add public members from.