Implement the "else" of the if section

4 files changed, 41 insertions, 7 deletions

diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/IfSection.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/IfSection.java
index 33e62750f69..6bf2811d72e 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/IfSection.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/IfSection.java
@@ -14,14 +14,16 @@ public class IfSection extends Section {
     private final String name;
     private final Cursor nameOffset;
     private final SectionList ifSections;
+    private final Optional<SectionList> elseSections;
 
     public IfSection(CursorRange range, boolean negated, String name, Cursor nameOffset,
-                     SectionList ifSections) {
+                     SectionList ifSections, Optional<SectionList> elseSections) {
         super(range);
         this.negated = negated;
         this.name = name;
         this.nameOffset = nameOffset;
         this.ifSections = ifSections;
+        this.elseSections = elseSections;
     }
 
     String name() { return name; }
@@ -45,6 +47,8 @@ public class IfSection extends Section {
         boolean condition = negated ? !value : value;
         if (condition) {
             ifSections.sections().forEach(section -> section.appendTo(buffer));
+        } else if (elseSections.isPresent()) {
+            elseSections.get().sections().forEach(section -> section.appendTo(buffer));
         }
     }
 
@@ -52,6 +56,13 @@ public class IfSection extends Section {
     void appendCopyTo(SectionList sectionList) {
         SectionList ifSectionCopy = new SectionList(ifSections.range().start(), sectionList.formBuilder());
         ifSections.sections().forEach(section -> section.appendCopyTo(ifSectionCopy));
-        sectionList.appendIfSection(negated, name, nameOffset, range().end(), ifSectionCopy);
+
+        Optional<SectionList> elseSectionCopy = elseSections.map(elseSections2 -> {
+            SectionList elseSectionCopy2 = new SectionList(elseSections2.range().start(), sectionList.formBuilder());
+            elseSections2.sections().forEach(section -> section.appendCopyTo(elseSectionCopy2));
+            return elseSectionCopy2;
+        });
+
+        sectionList.appendIfSection(negated, name, nameOffset, range().end(), ifSectionCopy, elseSectionCopy);
     }
 }
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/SectionList.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/SectionList.java
index 60949c5ffa0..b9a8c4e8c41 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/SectionList.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/SectionList.java
@@ -6,6 +6,7 @@ import com.yahoo.vespa.hosted.node.admin.task.util.text.CursorRange;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 
 /**
  * A mutable list of sections at the same level that can be used to build a form, e.g. the if-body.
@@ -45,9 +46,9 @@ class SectionList {
     }
 
     void appendIfSection(boolean negated, String name, Cursor nameOffset, Cursor end,
-                                SectionList ifSections) {
+                         SectionList ifSections, Optional<SectionList> elseSections) {
         CursorRange range = verifyAndUpdateEnd(end);
-        var section = new IfSection(range, negated, name, nameOffset, ifSections);
+        var section = new IfSection(range, negated, name, nameOffset, ifSections, elseSections);
         formBuilder.addIfSection(section);
         sections.add(section);
     }
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateParser.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateParser.java
index c81a07512b0..93a83a3d29f 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateParser.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateParser.java
@@ -27,7 +27,7 @@ class TemplateParser {
         return parser;
     }
 
-    private enum Sentinel { END, EOT }
+    private enum Sentinel { ELSE, END, EOT }
 
     private TemplateParser(TemplateDescriptor descriptor, Cursor start) {
         this.descriptor = descriptor;
@@ -69,6 +69,11 @@ class TemplateParser {
             String type = skipId().orElseThrow(() -> new BadTemplateException(current, "Missing section name"));
 
             switch (type) {
+                case "else":
+                    if (!sentinels.contains(Sentinel.ELSE))
+                        throw new BadTemplateException(startOfType, "Extraneous 'else'");
+                    parseEndDirective();
+                    return Optional.of(Sentinel.ELSE);
                 case "end":
                     if (!sentinels.contains(Sentinel.END))
                         throw new BadTemplateException(startOfType, "Extraneous 'end'");
@@ -120,9 +125,15 @@ class TemplateParser {
         parseEndDelimiter(true);
 
         SectionList ifSectionList = new SectionList(current, formBuilder);
-        parse(ifSectionList, EnumSet.of(Sentinel.END));
+        Sentinel ifSentinel = parse(ifSectionList, EnumSet.of(Sentinel.ELSE, Sentinel.END));
+
+        Optional<SectionList> elseSectionList = Optional.empty();
+        if (ifSentinel == Sentinel.ELSE) {
+            elseSectionList = Optional.of(new SectionList(current, formBuilder));
+            parse(elseSectionList.get(), EnumSet.of(Sentinel.END));
+        }
 
-        sectionList.appendIfSection(negated, name, startOfName, current, ifSectionList);
+        sectionList.appendIfSection(negated, name, startOfName, current, ifSectionList, elseSectionList);
     }
 
     private void skipRequiredWhitespaces() {
diff --git a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateFileTest.java b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateFileTest.java
index cc2228e7f77..807849bbdb6 100644
--- a/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateFileTest.java
+++ b/node-admin/src/test/java/com/yahoo/vespa/hosted/node/admin/task/util/template/TemplateFileTest.java
@@ -120,6 +120,17 @@ class TemplateFileTest {
                      "list: element\n", form.render());
     }
 
+    @Test
+    void verifyElse() {
+        var template = Template.from("%{if cond-}\n" +
+                                     "if body\n" +
+                                     "%{else-}\n" +
+                                     "else body\n" +
+                                     "%{end-}\n");
+        assertEquals("if body\n", template.instantiate().set("cond", true).render());
+        assertEquals("else body\n", template.instantiate().set("cond", false).render());
+    }
+
     private Form getForm(String filename) {
         return TemplateFile.read(Path.of("src/test/resources/" + filename)).instantiate();
     }