Add TagCreator::each(Map, BiFunction) (#115)

Author: mwanji

src/main/java/j2html/TagCreator.java

@@ -14,6 +14,7 @@
 import java.util.Map.Entry;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
@@ -99,6 +100,20 @@ public static <I, T> DomContent each(final Map<I, T> map, final Function<Entry<I
         return rawHtml(map.entrySet().stream().map(mapper.andThen(DomContent::render)).collect(Collectors.joining()));
     }
 
+    /**
+     * Creates a DomContent object containing HTML using a mapping function on a map
+     * Intended usage: {@literal each(idsToNames, (id, name) -> li(id + " " + name))}
+     *
+     * @param <I>        The type of the keys
+     * @param <T>        The type of the values
+     * @param map        the map to iterate over, ex: a map of values { 1: "Tom", 2: "Dick", 3: "Harry" }
+     * @param mapper     the mapping function, ex: {@literal "(id, name) -> li(id + " " + name)"}
+     * @return DomContent containing mapped data {@literal (ex. docs: [li(1 Tom), li(2 Dick), li(3 Harry)])}
+     */
+    public static <I, T> DomContent each(final Map<I, T> map, final BiFunction<I, T, DomContent> mapper) {
+        return rawHtml(map.entrySet().stream().map(entry -> mapper.andThen(DomContent::render).apply(entry.getKey(), entry.getValue())).collect(Collectors.joining()));
+    }
+
     /**
      * Filters a collection to a list, to be used with {@link j2html.TagCreator#each}
      * Intended usage: {@literal each(filter(numbers, n -> n % 2 == 0), n -> li(n.toString()))}

src/test/java/j2html/tags/TagCreatorTest.java

@@ -113,6 +113,16 @@ public void testEachWithMap() {
         assertThat(j2htmlMap, is("<ul><li>Begin list</li><li>1-Name 1</li><li>2-Name 2</li><li>3-Name 3</li></ul>"));
     }
 
+    @Test
+    public void testEachWithMapAndBiFunction() {
+        final String j2htmlMap = ul().with(
+            li("Begin list"),
+            each(employeeMap, (id, employee) -> li(id + "-" + employee.name))
+        ).render();
+
+        assertThat(j2htmlMap, is("<ul><li>Begin list</li><li>1-Name 1</li><li>2-Name 2</li><li>3-Name 3</li></ul>"));
+    }
+
     @Test
     public void testFilter() throws Exception {
         String j2htmlFilter = ul().with(