StringCollectionProperty: support for Iterable

core/src/main/java/io/github/mmm/property/string/StringCollectionProperty.java

@@ -3,9 +3,12 @@
 package io.github.mmm.property.string;
 
 import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
 import java.util.function.Consumer;
 
+import io.github.mmm.base.collection.AbstractIterator;
 import io.github.mmm.marshall.StructuredReader;
 import io.github.mmm.marshall.StructuredWriter;
 import io.github.mmm.property.PropertyMetadata;
@@ -22,7 +25,7 @@
  *
  * @since 1.0.0
  */
-public abstract class StringCollectionProperty extends StringProperty {
+public abstract class StringCollectionProperty extends StringProperty implements Iterable<String> {
 
   /**
    * The constructor.
@@ -504,4 +507,56 @@ public void write(StructuredWriter writer) {
     writer.writeEnd();
   }
 
+  @Override
+  public Iterator<String> iterator() {
+
+    String value = get();
+    if (value == null) {
+      return Collections.emptyIterator();
+    }
+    return new ValueIterator(value, getSeparator(), isEncloseWithSeparator());
+  }
+
+  private static class ValueIterator extends AbstractIterator<String> {
+
+    private final String string;
+
+    private final String separator;
+
+    private final int end;
+
+    private int index = 0;
+
+    private ValueIterator(String string, String separator, boolean enclose) {
+
+      super();
+      this.string = string;
+      this.separator = separator;
+      this.end = string.length();
+      if (enclose && string.startsWith(separator)) {
+        this.index = separator.length();
+      }
+      findFirst();
+    }
+
+    @Override
+    protected String findNext() {
+
+      if (this.index >= this.end) {
+        return null;
+      }
+      int i = this.string.indexOf(this.separator, this.index);
+      if (i < 0) {
+        i = this.end;
+      }
+      String result = this.string.substring(this.index, i);
+      this.index = i + this.separator.length();
+      if (this.index >= this.end) {
+        this.index = this.end;
+      }
+      return result;
+    }
+
+  }
+
 }

core/src/test/java/io/github/mmm/property/string/StringCollectionPropertyTest.java

@@ -295,4 +295,20 @@ public void testWriteArray() {
     assertThat(json).isEqualTo("[\"hit\",\"pop\",\"partyhit\",\"superhits\"]");
   }
 
+  /**
+   * Test {@link StringCollectionProperty#iterator()} after multiple elements have been added.
+   */
+  @Test
+  public void testIterable() {
+
+    // arrange
+    StringCollectionProperty property = createEmpty();
+    // act
+    property.add("one");
+    property.add("two");
+    property.add("three");
+    // assert
+    Iterable<String> iterable = property;
+    assertThat(iterable).containsExactly("one", "two", "three");
+  }
 }