add voidStatement and getStatementIterator to xApiEnhancedClient

README.md

@@ -101,6 +101,18 @@ StatementResult moreStatementResult = moreResponse.getBody();
 Statement[] statements = moreStatementResult.getStatements();
 ```
 
+### Getting Statements as Iterator (and processing them as a Stream)
+
+Example:
+
+```java
+var statements = client.getStatementIterator().block();
+
+// process the first 100 Statements
+statements.toStream().limit(100).forEach(s -> {
+    // add logic here...
+  });
+```
 
 ### Posting a Statement
 

samples/get-statement-iterator/pom.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>dev.learning.xapi.samples</groupId>
+    <artifactId>xapi-samples-build</artifactId>
+    <version>1.1.5-SNAPSHOT</version>
+  </parent>
+  <artifactId>get-statement-iterator</artifactId>
+  <name>Get xAPI StatementIterator Sample</name>
+  <description>Get xAPI StatementIterator</description>
+  <dependencies>
+    <dependency>
+      <groupId>dev.learning.xapi</groupId>
+      <artifactId>xapi-client</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>dev.learning.xapi.samples</groupId>
+      <artifactId>core</artifactId>
+    </dependency>
+  </dependencies>
+</project>

samples/get-statement-iterator/src/main/java/dev/learning/xapi/samples/getstatements/GetStatementIteratorApplication.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2016-2023 Berry Cloud Ltd. All rights reserved.
+ */
+
+package dev.learning.xapi.samples.getstatements;
+
+import dev.learning.xapi.client.XapiClient;
+import dev.learning.xapi.model.StatementResult;
+import dev.learning.xapi.model.Verb;
+import java.util.Arrays;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.http.ResponseEntity;
+
+/**
+ * Sample using xAPI client to get multiple statements as StatementIterator.
+ *
+ * @author Thomas Turrell-Croft
+ * @author István Rátkai (Selindek)
+ */
+@SpringBootApplication
+public class GetStatementIteratorApplication implements CommandLineRunner {
+
+  /**
+   * Default xAPI client. Properties are picked automatically from application.properties.
+   */
+  @Autowired
+  private XapiClient client;
+
+  public static void main(String[] args) {
+    SpringApplication.run(GetStatementIteratorApplication.class, args).close();
+  }
+
+  @Override
+  public void run(String... args) throws Exception {
+
+    // Get Statements as StatementIterator
+    var iterator = client.getStatementIterator().block();
+
+    // Print the returned statements to the console
+    iterator.toStream().forEach(s -> System.out.println(s));
+
+    // Get Statements with Verb filter as StatementIterator
+    var filteredStatements =
+        client.getStatementIterator(r -> r.verb(Verb.ATTEMPTED.getId())).block();
+
+    // Print the returned statements to the console
+    filteredStatements.toStream().forEach(s -> System.out.println(s));
+
+  }
+
+}

samples/get-statement-iterator/src/main/resources/application.properties

@@ -0,0 +1,3 @@
+xapi.client.username = admin
+xapi.client.password = password
+xapi.client.baseUrl = https://example.com/xapi/

samples/pom.xml

@@ -35,6 +35,7 @@
     <module>core</module>
     <!-- Statements Resource -->
     <module>get-statement</module>
+    <module>get-statement-iterator</module>
     <module>get-statement-with-attachment</module>
     <module>post-statement</module>
     <module>post-signed-statement</module>

xapi-client/src/main/java/dev/learning/xapi/client/XapiClient.java

@@ -6,16 +6,26 @@
 
 import dev.learning.xapi.model.About;
 import dev.learning.xapi.model.Activity;
+import dev.learning.xapi.model.Actor;
 import dev.learning.xapi.model.Person;
 import dev.learning.xapi.model.Statement;
 import dev.learning.xapi.model.StatementResult;
+import dev.learning.xapi.model.Verb;
+import java.net.URI;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.NoSuchElementException;
 import java.util.UUID;
 import java.util.function.Consumer;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+import lombok.RequiredArgsConstructor;
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.ResponseEntity;
+import org.springframework.util.Assert;
 import org.springframework.web.reactive.function.client.WebClient;
 import reactor.core.publisher.Mono;
 
@@ -1257,4 +1267,191 @@ public Mono<ResponseEntity<About>> getAbout() {
 
   }
 
+  // Enhanced features
+
+  /**
+   * Gets a list of Statements as a {@link StatementIterator}.
+   * <p>
+   * This method loads ALL of Statements which fullfills the request filters from the LRS
+   * dynamically. (It sends additional
+   * {@link XapiClient#getMoreStatements(java.util.function.Consumer)} request if all the previously
+   * loaded Statements were processed from the iterator.)
+   * </p>
+   *
+   * @param request The parameters of the get statements request
+   *
+   * @return a {@link StatementIterator} object as a {@link Mono}.
+   */
+  public Mono<StatementIterator> getStatementIterator(GetStatementsRequest request) {
+
+    return getStatements(request).map(result -> new StatementIterator(result));
+
+  }
+
+  /**
+   * Gets a list of Statements as a {@link StatementIterator}.
+   * <p>
+   * This method loads ALL of Statements which fullfills the request filters from the LRS
+   * dynamically. (It sends additional
+   * {@link XapiClient#getMoreStatements(java.util.function.Consumer)} request if all the previously
+   * loaded Statements were processed from the iterator.)
+   * </p>
+   *
+   * @param request The parameters of the get statements request
+   *
+   * @return a {@link StatementIterator} object as a {@link Mono}.
+   */
+  public Mono<StatementIterator> getStatementIterator(
+      Consumer<GetStatementsRequest.Builder> request) {
+
+    final var builder = GetStatementsRequest.builder();
+
+    request.accept(builder);
+
+    return getStatementIterator(builder.build());
+
+  }
+
+  /**
+   * Gets all of the Statements as a {@link StatementIterator}.
+   * <p>
+   * This method loads ALL of Statements which fullfills the request filters from the LRS
+   * dynamically. (It sends additional
+   * {@link XapiClient#getMoreStatements(java.util.function.Consumer)} request if all the previously
+   * loaded Statements were processed from the iterator.)
+   * </p>
+   *
+   * @return a {@link StatementIterator} object as a {@link Mono}.
+   */
+  public Mono<StatementIterator> getStatementIterator() {
+
+    return getStatementIterator(r -> {
+    });
+
+  }
+
+  /**
+   * <p>
+   * Voids a {@link Statement}.
+   * </p>
+   * The Actor of the voiding statement will be the same as the Actor of the target Statement.
+   * <p>
+   * The returned ResponseEntity contains the response headers and the Statement identifier of the
+   * generated voiding Statement.
+   * </p>
+   *
+   * @param targetStatement The {@link Statement} to be voided
+   *
+   * @return the ResponseEntity
+   */
+  public Mono<ResponseEntity<UUID>> voidStatement(Statement targetStatement) {
+    return voidStatement(targetStatement, targetStatement.getActor());
+  }
+
+  /**
+   * Voids a {@link Statement}.
+   * <p>
+   * The returned ResponseEntity contains the response headers and the Statement identifier of the
+   * generated voiding Statement.
+   * </p>
+   *
+   * @param targetStatement The {@link Statement} to be voided
+   * @param actor the Actor of the voiding Statement
+   *
+   * @return the ResponseEntity
+   */
+  public Mono<ResponseEntity<UUID>> voidStatement(Statement targetStatement, Actor actor) {
+    return voidStatement(targetStatement.getId(), actor);
+  }
+
+  /**
+   * Voids a {@link Statement}.
+   * <p>
+   * The returned ResponseEntity contains the response headers and the Statement identifier of the
+   * generated voiding Statement.
+   * </p>
+   *
+   * @param targetStatementId The id of the {@link Statement} to be voided
+   * @param actor the Actor of the voiding Statement
+   *
+   * @return the ResponseEntity
+   */
+  public Mono<ResponseEntity<UUID>> voidStatement(UUID targetStatementId, Actor actor) {
+    Assert.notNull(targetStatementId, "Target Statement id cannot be null");
+    Assert.notNull(actor, "Actor cannot be null");
+
+    return postStatement(r -> r
+
+        .statement(s -> s
+
+            .actor(actor)
+
+            .verb(Verb.VOIDED)
+
+            .statementReferenceObject(o -> o
+
+                .id(targetStatementId)
+
+            )
+
+        )
+
+    );
+
+  }
+
+  /**
+   * <p>
+   * StatementIterator.
+   * </p>
+   * Iterates through the Statements of the result of a
+   * {@link XapiClient#getStatements(GetStatementsRequest)}. If more Statements are available it
+   * automatically loads them from the server.
+   *
+   * @author István Rátkai (Selindek)
+   */
+  @RequiredArgsConstructor
+  public class StatementIterator implements Iterator<Statement> {
+
+    private URI more;
+    private Iterator<Statement> statements;
+
+    private StatementIterator(ResponseEntity<StatementResult> response) {
+      init(response);
+    }
+
+    /**
+     * Convenient method for transforming this StatementIterator to a {@link Stream}.
+     *
+     * @return a {@link Stream} of {@link Statement}s
+     */
+    public Stream<Statement> toStream() {
+      final Iterable<Statement> iterable = () -> this;
+      return StreamSupport.stream(iterable.spliterator(), false);
+    }
+
+    private void init(ResponseEntity<StatementResult> response) {
+      final var statementResult = response.getBody();
+      more = statementResult.hasMore() ? statementResult.getMore() : null;
+      final var s = statementResult.getStatements();
+      statements = s == null ? Collections.emptyIterator() : s.iterator();
+    }
+
+    @Override
+    public boolean hasNext() {
+      return statements.hasNext() || more != null;
+    }
+
+    @Override
+    public Statement next() {
+      if (!statements.hasNext()) {
+        if (more == null) {
+          throw new NoSuchElementException();
+        }
+        init(getMoreStatements(r -> r.more(more)).block());
+      }
+      return statements.next();
+    }
+
+  }
 }