/**
* A link:javadocs/org/neo4j/graphdb/traversal/TraversalDescription.html[traversal description] is
* built using a fluent interface and such a description can then spawn
* link:javadocs/org/neo4j/graphdb/traversal/Traverser.html[traversers]. @@graph
*
* <p>With the definition of the +RelationshipTypes+ as @@sourceRels
*
* <p>The graph can be traversed with for example the following traverser, starting at the ``Joe''
* node: @@knowslikestraverser
*
* <p>The traversal will output: @@knowslikesoutput
*
* <p>Since
* link:javadocs/org/neo4j/graphdb/traversal/TraversalDescription.html[+TraversalDescription+]s
* are immutable it is also useful to create template descriptions which holds common settings
* shared by different traversals. For example, let's start with this traverser: @@basetraverser
*
* <p>This traverser would yield the following output (we will keep starting from the ``Joe''
* node): @@baseoutput
*
* <p>Now let's create a new traverser from it, restricting depth to three: @@depth3
*
* <p>This will give us the following result: @@output3
*
* <p>Or how about from depth two to four? That's done like this: @@depth4
*
* <p>This traversal gives us: @@output4
*
* <p>For various useful evaluators, see the
* link:javadocs/org/neo4j/graphdb/traversal/Evaluators.html[Evaluators] Java API or simply
* implement the link:javadocs/org/neo4j/graphdb/traversal/Evaluator.html[Evaluator] interface
* yourself.
*
* <p>If you're not interested in the link:javadocs/org/neo4j/graphdb/Path.html[+Path+]s, but the
* link:javadocs/org/neo4j/graphdb/Node.html[+Node+]s you can transform the traverser into an
* iterable of link:javadocs/org/neo4j/graphdb/traversal/Traverser.html#nodes()[nodes] like
* this: @@nodes
*
* <p>In this case we use it to retrieve the names: @@nodeoutput
*
* <p>link:javadocs/org/neo4j/graphdb/traversal/Traverser.html#relationships()[Relationships] are
* fine as well, here's how to get them: @@relationships
*
* <p>Here the relationship types are written, and we get: @@relationshipoutput
*
* <p>TIP: The source code for the traversers in this example is available at: @@github
*/
@Test
@Documented
@Graph({
"Joe KNOWS Sara",
"Lisa LIKES Joe",
"Peter KNOWS Sara",
"Dirk KNOWS Peter",
"Lars KNOWS Dirk",
"Ed KNOWS Lars",
"Lisa KNOWS Lars"
})
public void how_to_use_the_Traversal_framework() {
Node joe = data.get().get("Joe");
TraversalExample example = new TraversalExample(db);
gen.get()
.addSnippet(
"graph",
createGraphVizWithNodeId("Traversal Example Graph", graphdb(), gen.get().getTitle()));
try (Transaction tx = db.beginTx()) {
String output = example.knowsLikesTraverser(joe);
gen.get().addSnippet("knowslikesoutput", createOutputSnippet(output));
output = example.traverseBaseTraverser(joe);
gen.get().addSnippet("baseoutput", createOutputSnippet(output));
output = example.depth3(joe);
gen.get().addSnippet("output3", createOutputSnippet(output));
output = example.depth4(joe);
gen.get().addSnippet("output4", createOutputSnippet(output));
output = example.nodes(joe);
gen.get().addSnippet("nodeoutput", createOutputSnippet(output));
output = example.relationships(joe);
gen.get().addSnippet("relationshipoutput", createOutputSnippet(output));
gen.get()
.addSourceSnippets(
example.getClass(),
"knowslikestraverser",
"sourceRels",
"basetraverser",
"depth3",
"depth4",
"nodes",
"relationships");
gen.get().addGithubSourceLink("github", example.getClass(), "community/embedded-examples");
}
}
@Test
public void runAll() throws IOException {
TraversalExample.main(null);
}