TagBuilder implemented and available in templates, parts, and specialPages.

lib/src/main/groovy/com/jessebrault/ssg/part/GspPartRenderer.groovy

@@ -1,6 +1,7 @@
 package com.jessebrault.ssg.part
 
 import com.jessebrault.ssg.Diagnostic
+import com.jessebrault.ssg.tagbuilder.DynamicTagBuilder
 import com.jessebrault.ssg.text.EmbeddableText
 import groovy.text.GStringTemplateEngine
 import groovy.text.TemplateEngine
@@ -26,6 +27,7 @@ class GspPartRenderer implements PartRenderer {
             def result = engine.createTemplate(part.text).make([
                     binding: binding,
                     globals: globals,
+                    tagBuilder: new DynamicTagBuilder(),
                     text: text
             ])
             new Tuple2<>([], result.toString())

lib/src/main/groovy/com/jessebrault/ssg/specialpage/GspSpecialPageRenderer.groovy

@@ -3,6 +3,7 @@ package com.jessebrault.ssg.specialpage
 import com.jessebrault.ssg.Diagnostic
 import com.jessebrault.ssg.part.Part
 import com.jessebrault.ssg.part.EmbeddablePartsMap
+import com.jessebrault.ssg.tagbuilder.DynamicTagBuilder
 import com.jessebrault.ssg.text.EmbeddableTextsCollection
 import com.jessebrault.ssg.text.Text
 import groovy.text.GStringTemplateEngine
@@ -25,6 +26,7 @@ class GspSpecialPageRenderer implements SpecialPageRenderer {
                     parts: new EmbeddablePartsMap(parts, globals, { Collection<Diagnostic> partDiagnostics ->
                         diagnostics.addAll(partDiagnostics)
                     }),
+                    tagBuilder: new DynamicTagBuilder(),
                     texts: new EmbeddableTextsCollection(texts, globals, { Collection<Diagnostic> textDiagnostics ->
                         diagnostics.addAll(textDiagnostics)
                     })

lib/src/main/groovy/com/jessebrault/ssg/tagbuilder/DynamicTagBuilder.groovy

@@ -0,0 +1,77 @@
+package com.jessebrault.ssg.tagbuilder
+
+import org.codehaus.groovy.runtime.InvokerHelper
+
+class DynamicTagBuilder implements TagBuilder {
+
+    @Override
+    String create(String name) {
+        "<$name />"
+    }
+
+    @Override
+    String create(String name, Map<String, ?> attributes) {
+        def formattedAttributes = attributes.collect {
+            if (it.value instanceof String) {
+                it.key + '="' + it.value + '"'
+            } else if (it.value instanceof Integer) {
+                it.key + '=' + it.value
+            } else if (it.value instanceof Boolean && it.value == true) {
+                it.key
+            } else {
+                it.key + '="' + it.value.toString() + '"'
+            }
+        }.join(' ')
+        "<$name $formattedAttributes />"
+    }
+
+    @Override
+    String create(String name, String body) {
+        "<$name>$body</$name>"
+    }
+
+    @Override
+    String create(String name, Map<String, ?> attributes, String body) {
+        def formattedAttributes = attributes.collect {
+            if (it.value instanceof String) {
+                it.key + '="' + it.value + '"'
+            } else if (it.value instanceof Integer) {
+                it.key + '=' + it.value
+            } else if (it.value instanceof Boolean && it.value == true) {
+                it.key
+            } else {
+                it.key + '="' + it.value.toString() + '"'
+            }
+        }.join(' ')
+        "<$name $formattedAttributes>$body</$name>"
+    }
+
+    @Override
+    Object invokeMethod(String name, Object args) {
+        def argsList = InvokerHelper.asList(args)
+        return switch (argsList.size()) {
+            case 0 -> this.create(name)
+            case 1 -> {
+                def arg0 = argsList[0]
+                if (arg0 instanceof Map) {
+                    this.create(name, arg0)
+                } else if (arg0 instanceof String) {
+                    this.create(name, arg0)
+                } else {
+                    throw new MissingMethodException(name, this.class, args, false)
+                }
+            }
+            case 2 -> {
+                def arg0 = argsList[0]
+                def arg1 = argsList[1]
+                if (arg0 instanceof Map && arg1 instanceof String) {
+                    this.create(name, arg0, arg1)
+                } else {
+                    throw new MissingMethodException(name, this.class, args, false)
+                }
+            }
+            default -> throw new MissingMethodException(name, this.class, args, false)
+        }
+    }
+
+}

lib/src/main/groovy/com/jessebrault/ssg/tagbuilder/TagBuilder.groovy

@@ -0,0 +1,8 @@
+package com.jessebrault.ssg.tagbuilder
+
+interface TagBuilder {
+    String create(String name)
+    String create(String name, Map<String, ?> attributes)
+    String create(String name, String body)
+    String create(String name, Map<String, ?> attributes, String body)
+}

lib/src/main/groovy/com/jessebrault/ssg/template/GspTemplateRenderer.groovy

@@ -3,6 +3,7 @@ package com.jessebrault.ssg.template
 import com.jessebrault.ssg.Diagnostic
 import com.jessebrault.ssg.part.EmbeddablePartsMap
 import com.jessebrault.ssg.part.Part
+import com.jessebrault.ssg.tagbuilder.DynamicTagBuilder
 import com.jessebrault.ssg.text.EmbeddableText
 import com.jessebrault.ssg.text.FrontMatter
 import com.jessebrault.ssg.text.Text
@@ -35,6 +36,7 @@ class GspTemplateRenderer implements TemplateRenderer {
                     frontMatter: frontMatter,
                     globals: globals,
                     parts: new EmbeddablePartsMap(parts, globals, onDiagnostics, embeddableText),
+                    tagBuilder: new DynamicTagBuilder(),
                     text: embeddableText
             ])
             new Tuple2<>(diagnostics, result.toString())

lib/src/test/groovy/com/jessebrault/ssg/part/GspPartRendererTests.groovy

@@ -68,4 +68,12 @@ class GspPartRendererTests {
         assertEquals('Hello, World!', r.v2)
     }
 
+    @Test
+    void tagBuilderAvailable() {
+        def part = new Part('', null, '<%= tagBuilder.test() %>')
+        def r = this.renderer.render(part, [:], [:], null)
+        assertTrue(r.v1.isEmpty())
+        assertEquals('<test />', r.v2)
+    }
+
 }

lib/src/test/groovy/com/jessebrault/ssg/specialpage/GspSpecialPageRendererTests.groovy

@@ -75,4 +75,12 @@ class GspSpecialPageRendererTests {
         assertEquals('<p><strong>Hello, World!</strong></p>\n', r.v2)
     }
 
+    @Test
+    void tagBuilderAvailable() {
+        def specialPage = new SpecialPage('<%= tagBuilder.test() %>', null, null)
+        def r = this.renderer.render(specialPage, [], [], [:])
+        assertTrue(r.v1.isEmpty())
+        assertEquals('<test />', r.v2)
+    }
+
 }

lib/src/test/groovy/com/jessebrault/ssg/tagbuilder/TagBuilderTests.groovy

@@ -0,0 +1,54 @@
+package com.jessebrault.ssg.tagbuilder
+
+import org.junit.jupiter.api.Test
+
+import static org.junit.jupiter.api.Assertions.assertEquals
+
+class TagBuilderTests {
+
+    private final TagBuilder tagBuilder = new DynamicTagBuilder()
+
+    @Test
+    void simple() {
+        assertEquals('<test />', this.tagBuilder.create('test'))
+    }
+
+    @Test
+    void withAttributes() {
+        assertEquals('<test test="abc" />', this.tagBuilder.create('test', [test: 'abc']))
+    }
+
+    @Test
+    void withBody() {
+        assertEquals('<test>test</test>', this.tagBuilder.create('test', 'test'))
+    }
+
+    @Test
+    void withAttributesAndBody() {
+        assertEquals(
+                '<test test="abc">test</test>',
+                this.tagBuilder.create('test', [test: 'abc'], 'test')
+        )
+    }
+
+    @Test
+    void dynamicSimple() {
+        assertEquals('<test />', this.tagBuilder.test())
+    }
+
+    @Test
+    void dynamicWithAttributes() {
+        assertEquals('<test test="abc" />', this.tagBuilder.test([test: 'abc']))
+    }
+
+    @Test
+    void dynamicWithBody() {
+        assertEquals('<test>test</test>', this.tagBuilder.test('test'))
+    }
+
+    @Test
+    void dynamicWithAttributesAndBody() {
+        assertEquals('<test test="abc">test</test>', this.tagBuilder.test([test: 'abc'], 'test'))
+    }
+
+}

lib/src/test/groovy/com/jessebrault/ssg/template/GspTemplateRendererTests.groovy

@@ -136,4 +136,18 @@ class GspTemplateRendererTests {
         assertEquals('Hello, World!', r.v2)
     }
 
+    @Test
+    void tagBuilderAvailable() {
+        def template = new Template('<%= tagBuilder.test() %>', null, null)
+        def r = this.renderer.render(
+                template,
+                new FrontMatter(null, [:]),
+                mockBlankText(),
+                [],
+                [:]
+        )
+        assertTrue(r.v1.isEmpty())
+        assertEquals('<test />', r.v2)
+    }
+
 }