From 0ea271afbea406a9ebeb24712255a50cbbd5c83d Mon Sep 17 00:00:00 2001 From: Michael Williamson Date: Tue, 16 Feb 2016 21:29:30 +0000 Subject: Collapse nodes where appropriate --- src/main/java/org/zwobble/mammoth/html/Html.java | 73 +++++++++++++++++++++- src/main/java/org/zwobble/mammoth/util/Casts.java | 13 ++++ .../org/zwobble/mammoth/util/MammothIterables.java | 11 ++++ .../org/zwobble/mammoth/util/MammothOptionals.java | 12 ++++ .../mammoth/tests/html/HtmlCollapseTests.java | 64 +++++++++++++++++++ 5 files changed, 172 insertions(+), 1 deletion(-) create mode 100644 src/main/java/org/zwobble/mammoth/util/Casts.java create mode 100644 src/main/java/org/zwobble/mammoth/util/MammothIterables.java diff --git a/src/main/java/org/zwobble/mammoth/html/Html.java b/src/main/java/org/zwobble/mammoth/html/Html.java index 14298b7..c0b234b 100644 --- a/src/main/java/org/zwobble/mammoth/html/Html.java +++ b/src/main/java/org/zwobble/mammoth/html/Html.java @@ -1,10 +1,14 @@ package org.zwobble.mammoth.html; import org.zwobble.mammoth.util.MammothLists; +import org.zwobble.mammoth.util.MammothOptionals; +import java.util.ArrayList; import java.util.List; import java.util.Map; +import static org.zwobble.mammoth.util.Casts.tryCast; +import static org.zwobble.mammoth.util.MammothIterables.tryGetLast; import static org.zwobble.mammoth.util.MammothLists.list; import static org.zwobble.mammoth.util.MammothMaps.map; @@ -37,6 +41,10 @@ public class Html { return new HtmlElement(tagName, attributes, children, false); } + public static HtmlNode collapsibleElement(String tagName) { + return collapsibleElement(tagName, list()); + } + public static HtmlNode collapsibleElement(String tagName, List children) { return collapsibleElement(tagName, map(), children); } @@ -95,6 +103,69 @@ public class Html { } public static List collapse(List nodes) { - return nodes; + List collapsed = new ArrayList<>(); + + for (HtmlNode node : nodes) { + collapsingAdd(collapsed, node); + } + + return collapsed; + } + + private static void collapsingAdd(List collapsed, HtmlNode node) { + HtmlNode collapsedNode = collapse(node); + if (!tryCollapse(collapsed, collapsedNode)) { + collapsed.add(collapsedNode); + } + } + + private static HtmlNode collapse(HtmlNode node) { + return node.accept(new HtmlNode.Mapper() { + @Override + public HtmlNode visit(HtmlElement element) { + return new HtmlElement( + element.getTagName(), + element.getAttributes(), + collapse(element.getChildren()), + element.isCollapsible()); + } + + @Override + public HtmlNode visit(HtmlSelfClosingElement element) { + return element; + } + + @Override + public HtmlNode visit(HtmlTextNode node) { + return node; + } + + @Override + public HtmlNode visit(HtmlForceWrite forceWrite) { + return forceWrite; + } + }); + } + + private static boolean tryCollapse(List collapsed, HtmlNode node) { + return MammothOptionals.map( + tryGetLast(collapsed).flatMap(last -> tryCast(HtmlElement.class, last)), + tryCast(HtmlElement.class, node), + (last, next) -> { + if (next.isCollapsible() && isMatch(last, next)) { + for (HtmlNode child : next.getChildren()) { + collapsingAdd(last.getChildren(), child); + } + return true; + } else { + return false; + } + } + ).orElse(false); + } + + private static boolean isMatch(HtmlElement first, HtmlElement second) { + return first.getTagName().equals(second.getTagName()) && + first.getAttributes().equals(second.getAttributes()); } } diff --git a/src/main/java/org/zwobble/mammoth/util/Casts.java b/src/main/java/org/zwobble/mammoth/util/Casts.java new file mode 100644 index 0000000..0925990 --- /dev/null +++ b/src/main/java/org/zwobble/mammoth/util/Casts.java @@ -0,0 +1,13 @@ +package org.zwobble.mammoth.util; + +import java.util.Optional; + +public class Casts { + public static Optional tryCast(Class type, Object value) { + try { + return Optional.of(type.cast(value)); + } catch (ClassCastException exception) { + return Optional.empty(); + } + } +} diff --git a/src/main/java/org/zwobble/mammoth/util/MammothIterables.java b/src/main/java/org/zwobble/mammoth/util/MammothIterables.java new file mode 100644 index 0000000..89caf61 --- /dev/null +++ b/src/main/java/org/zwobble/mammoth/util/MammothIterables.java @@ -0,0 +1,11 @@ +package org.zwobble.mammoth.util; + +import com.google.common.collect.Iterables; + +import java.util.Optional; + +public class MammothIterables { + public static Optional tryGetLast(Iterable iterable) { + return Optional.ofNullable(Iterables.getLast(iterable, null)); + } +} diff --git a/src/main/java/org/zwobble/mammoth/util/MammothOptionals.java b/src/main/java/org/zwobble/mammoth/util/MammothOptionals.java index e0e4876..6890f16 100644 --- a/src/main/java/org/zwobble/mammoth/util/MammothOptionals.java +++ b/src/main/java/org/zwobble/mammoth/util/MammothOptionals.java @@ -15,4 +15,16 @@ public class MammothOptionals { return Optional.empty(); } } + + public static Optional map( + Optional first, + Optional second, + BiFunction function) + { + if (first.isPresent() && second.isPresent()) { + return Optional.of(function.apply(first.get(), second.get())); + } else { + return Optional.empty(); + } + } } diff --git a/src/test/java/org/zwobble/mammoth/tests/html/HtmlCollapseTests.java b/src/test/java/org/zwobble/mammoth/tests/html/HtmlCollapseTests.java index 18716c6..8a25385 100644 --- a/src/test/java/org/zwobble/mammoth/tests/html/HtmlCollapseTests.java +++ b/src/test/java/org/zwobble/mammoth/tests/html/HtmlCollapseTests.java @@ -6,6 +6,7 @@ import org.zwobble.mammoth.html.Html; import static org.hamcrest.MatcherAssert.assertThat; import static org.zwobble.mammoth.tests.DeepReflectionMatcher.deepEquals; import static org.zwobble.mammoth.util.MammothLists.list; +import static org.zwobble.mammoth.util.MammothMaps.map; public class HtmlCollapseTests { @Test @@ -14,4 +15,67 @@ public class HtmlCollapseTests { Html.collapse(list(Html.text("Bluebells"))), deepEquals(list(Html.text("Bluebells")))); } + + @Test + public void consecutiveFreshElementsAreNotCollapsed() { + assertThat( + Html.collapse(list(Html.element("p"), Html.element("p"))), + deepEquals(list(Html.element("p"), Html.element("p")))); + } + + @Test + public void consecutiveCollapsibleElementsAreCollapsedIfTheyHaveTheSameTagAndAttributes() { + assertThat( + Html.collapse(list( + Html.collapsibleElement("p", list(Html.text("One"))), + Html.collapsibleElement("p", list(Html.text("Two"))))), + + deepEquals(list(Html.collapsibleElement("p", list(Html.text("One"), Html.text("Two")))))); + } + + @Test + public void elementsWithDifferentTagNamesAreNotCollapsed() { + assertThat( + Html.collapse(list( + Html.collapsibleElement("p", list(Html.text("One"))), + Html.collapsibleElement("div", list(Html.text("Two"))))), + + deepEquals(list( + Html.collapsibleElement("p", list(Html.text("One"))), + Html.collapsibleElement("div", list(Html.text("Two")))))); + } + + @Test + public void elementsWithDifferentAttributesAreNotCollapsed() { + // TODO: should there be some spacing when block-level elements are collapsed? + assertThat( + Html.collapse(list( + Html.collapsibleElement("p", map("id", "a"), list(Html.text("One"))), + Html.collapsibleElement("p", list(Html.text("Two"))))), + + deepEquals(list( + Html.collapsibleElement("p", map("id", "a"), list(Html.text("One"))), + Html.collapsibleElement("p", list(Html.text("Two")))))); + } + + @Test + public void childrenOfCollapsedElementCanCollapseWithChildrenOfPreviousElement() { + assertThat( + Html.collapse(list( + Html.collapsibleElement("blockquote", list( + Html.collapsibleElement("p", list(Html.text("One"))))), + Html.collapsibleElement("blockquote", list( + Html.collapsibleElement("p", list(Html.text("Two"))))))), + + deepEquals(list( + Html.collapsibleElement("blockquote", list( + Html.collapsibleElement("p", list(Html.text("One"), Html.text("Two")))))))); + } + + @Test + public void collapsibleElementCanCollapseIntoPreviousFreshElement() { + assertThat( + Html.collapse(list(Html.element("p"), Html.collapsibleElement("p"))), + deepEquals(list(Html.element("p")))); + } } -- cgit v1.2.3