Class RemoveEmptyNonLeafQueryNodeProcessor
This processor removes every IQueryNode that is not a leaf and has not children. If after processing the entire tree the root node is not a leaf and has no children, a MatchNoDocsQueryNode object is returned.
This processor is used at the end of a pipeline to avoid invalid query node tree structures like a GroupQueryNode or ModifierQueryNode with no children.Implements
Inherited Members
Namespace: Lucene.Net.QueryParsers.Flexible.Standard.Processors
Assembly: Lucene.Net.QueryParser.dll
Syntax
public class RemoveEmptyNonLeafQueryNodeProcessor : QueryNodeProcessor, IQueryNodeProcessorConstructors
RemoveEmptyNonLeafQueryNodeProcessor()
This processor removes every IQueryNode that is not a leaf and has not children. If after processing the entire tree the root node is not a leaf and has no children, a MatchNoDocsQueryNode object is returned.
This processor is used at the end of a pipeline to avoid invalid query node tree structures like a GroupQueryNode or ModifierQueryNode with no children.Declaration
public RemoveEmptyNonLeafQueryNodeProcessor()See Also
Methods
PostProcessNode(IQueryNode)
This method is invoked for every node when walking up the tree.
Declaration
protected override IQueryNode PostProcessNode(IQueryNode node)Parameters
| Type | Name | Description |
|---|---|---|
| IQueryNode | node | node the query node to be post-processed |
Returns
| Type | Description |
|---|---|
| IQueryNode | a query node |
Overrides
Exceptions
| Type | Condition |
|---|---|
| QueryNodeException | if something goes wrong during the query node processing |
See Also
PreProcessNode(IQueryNode)
This method is invoked for every node when walking down the tree.
Declaration
protected override IQueryNode PreProcessNode(IQueryNode node)Parameters
| Type | Name | Description |
|---|---|---|
| IQueryNode | node | the query node to be pre-processed |
Returns
| Type | Description |
|---|---|
| IQueryNode | a query node |
Overrides
Exceptions
| Type | Condition |
|---|---|
| QueryNodeException | if something goes wrong during the query node processing |
See Also
Process(IQueryNode)
Processes a query node tree. It may return the same or another query tree.
I should never return null.
Declaration
public override IQueryNode Process(IQueryNode queryTree)Parameters
| Type | Name | Description |
|---|---|---|
| IQueryNode | queryTree | tree root node |
Returns
| Type | Description |
|---|---|
| IQueryNode | the processed query tree |
Overrides
See Also
SetChildrenOrder(IList<IQueryNode>)
This method is invoked for every node that has at least on child. It's invoked right before PostProcessNode(IQueryNode) is invoked.
Declaration
protected override IList<IQueryNode> SetChildrenOrder(IList<IQueryNode> children)Parameters
| Type | Name | Description |
|---|---|---|
| IList<IQueryNode> | children | the list containing all current node's children |
Returns
| Type | Description |
|---|---|
| IList<IQueryNode> | a new list containing all children that should be set to the current node |
Overrides
Exceptions
| Type | Condition |
|---|---|
| QueryNodeException | if something goes wrong during the query node processing |