com.github.fge.jsonschema.walk

Interface SchemaListener<T>

Type Parameters:

T - the value type produced by this listener

All Known Implementing Classes:

SchemaExpander

public interface SchemaListener<T>

A schema walker listener

This is the main working part of a walking process. A SchemaWalker will invoke a listener at various points in time when it walks a schema tree.

All methods can throw a ProcessingException if you choose to abort processing due to an anomalous condition.

For one subtree, the order in which events are called are:

• onEnter(JsonPointer) (visiting a subtree);
• onTreeChange(SchemaTree, SchemaTree) (only if ResolvingSchemaWalker is used);
• onWalk(SchemaTree);
• onExit(JsonPointer) (exiting a subtree).

For instance, if we consider this schema:

     {
         "type": "array",
         "items": { "type": "string" }
     }
 

for a listener listener, the order of events will be:

     // Note: JSON Pointers used for both pointers and trees
     listener.onEnter("");
     listener.onWalk("");
     listener.onEnter("/items");
     listener.onWalk("/items");
     listener.onExit();
     listener.onExit();
 

Method Summary

Methods

Modifier and Type	Method and Description
T	getValue() Return the value produced by this listener
void	onEnter(JsonPointer pointer) Method called when the walker changes pointer into the currently walked tree
void	onExit(JsonPointer pointer) Method called when the walking process exits a subtree
void	onTreeChange(SchemaTree oldTree, SchemaTree newTree) Method called when the walking process changes trees
void	onWalk(SchemaTree tree) Method called when the current tree node is walked

Method Detail

onTreeChange

void onTreeChange(SchemaTree oldTree,
                SchemaTree newTree)
                  throws ProcessingException

Method called when the walking process changes trees

Parameters:

oldTree - the old tree

newTree - the new tree

Throws:

ProcessingException - processing failure

See Also:

ResolvingSchemaWalker

onWalk

void onWalk(SchemaTree tree)
            throws ProcessingException

Method called when the current tree node is walked

Parameters:

tree - the current tree

Throws:

ProcessingException - processing failure

onEnter

void onEnter(JsonPointer pointer)
             throws ProcessingException

Method called when the walker changes pointer into the currently walked tree

Parameters:

pointer - the relative pointer into the tree

Throws:

ProcessingException - processing failure

onExit

void onExit(JsonPointer pointer)
            throws ProcessingException

Method called when the walking process exits a subtree

Parameters:

pointer - the relative pointer into the tree

Throws:

ProcessingException - processing failure

getValue

T getValue()

Return the value produced by this listener

Returns:

the value