Added RenderUtils and more tests.

lib/src/main/java/rife/render/Capitalize.java

@@ -40,11 +40,7 @@ public class Capitalize implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            var value = template.getValue(differentiator);
+        var value = RenderUtils.fetchValue(template, differentiator);
         return value.substring(0, 1).toUpperCase(Localization.getLocale()) + value.substring(1);
-        } else {
-            return "";
-        }
     }
 }

lib/src/main/java/rife/render/EncodeBase64.java

@@ -43,10 +43,7 @@ public class EncodeBase64 implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return StringUtils.encodeBase64(template.getValue(differentiator).getBytes(StandardCharsets.UTF_8));
-        } else {
-            return "";
-        }
+        return StringUtils.encodeBase64(RenderUtils.fetchValue(template, differentiator)
+                .getBytes(StandardCharsets.UTF_8));
     }
 }

lib/src/main/java/rife/render/EncodeHtml.java

@@ -41,10 +41,6 @@ public class EncodeHtml implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return StringUtils.encodeHtml(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return StringUtils.encodeHtml(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/EncodeHtmlEntities.java

@@ -59,10 +59,6 @@ public class EncodeHtmlEntities implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return toHtmlEntities(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return toHtmlEntities(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/EncodeJson.java

@@ -41,10 +41,6 @@ public class EncodeJson implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return StringUtils.encodeJson(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return StringUtils.encodeJson(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/EncodeQp.java

@@ -76,10 +76,6 @@ public class EncodeQp implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return toQuotedPrintable(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return toQuotedPrintable(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/EncodeUnicode.java

@@ -41,10 +41,6 @@ public class EncodeUnicode implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return StringUtils.encodeUnicode(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return StringUtils.encodeUnicode(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/EncodeUrl.java

@@ -41,14 +41,6 @@ public class EncodeUrl implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        String value;
-        if (template.hasValueId(differentiator)) {
-            value = template.getValue(differentiator);
-        } else if (template.hasAttribute(differentiator)) {
-            value = template.getAttribute(differentiator).toString();
-        } else {
-            return "";
-        }
-        return StringUtils.encodeUrl(value);
+        return StringUtils.encodeUrl(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/EncodeXml.java

@@ -41,10 +41,6 @@ public class EncodeXml implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return StringUtils.encodeXml(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return StringUtils.encodeXml(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/Lowercase.java

@@ -40,10 +40,6 @@ public class Lowercase implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return template.getValue(differentiator).toLowerCase(Localization.getLocale());
-        } else {
-            return "";
-        }
+        return RenderUtils.fetchValue(template, differentiator).toLowerCase(Localization.getLocale());
     }
 }

lib/src/main/java/rife/render/RenderUtils.java

@@ -0,0 +1,48 @@
+/*
+ *  Copyright 2023 the original author or authors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+package rife.render;
+
+import rife.template.Template;
+import rife.tools.Convert;
+
+/**
+ * Collection of utility-type methods commonly used by the renderers.
+ */
+public final  class RenderUtils {
+    private RenderUtils() {
+        // no-op
+    }
+
+    /**
+     * Fetches the specified value from a template or template's attribute.
+     *
+     * @param template the template
+     * @param valueId  the ID of the value to fetch
+     * @return The fetched value.
+     */
+    public static String fetchValue(Template template, String valueId) {
+        Object value = null;
+        if (template.hasValueId(valueId)) {
+            value = template.getValue(valueId);
+        }
+        if (value == null && template.hasAttribute(valueId)) {
+            value = template.getAttribute(valueId);
+        }
+        return Convert.toString(value);
+    }
+}

lib/src/main/java/rife/render/Rot13.java

@@ -77,10 +77,6 @@ public class Rot13 implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return rot13(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return rot13(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/SwapCase.java

@@ -70,10 +70,6 @@ public class SwapCase implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return swapCase(template.getValue(differentiator));
-        } else {
-            return "";
-        }
+        return swapCase(RenderUtils.fetchValue(template, differentiator));
     }
 }

lib/src/main/java/rife/render/Trim.java

@@ -39,10 +39,6 @@ public class Trim implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return template.getValue(differentiator).trim();
-        } else {
-            return "";
-        }
+        return RenderUtils.fetchValue(template, differentiator).trim();
     }
 }

lib/src/main/java/rife/render/Uncapitalize.java

@@ -40,11 +40,7 @@ public class Uncapitalize implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            var value = template.getValue(differentiator);
+        var value = RenderUtils.fetchValue(template, differentiator);
         return value.substring(0, 1).toLowerCase(Localization.getLocale()) + value.substring(1);
-        } else {
-            return "";
-        }
     }
 }

lib/src/main/java/rife/render/Uppercase.java

@@ -40,10 +40,6 @@ public class Uppercase implements ValueRenderer {
      */
     @Override
     public String render(Template template, String valueId, String differentiator) {
-        if (template.hasValueId(differentiator)) {
-            return template.getValue(differentiator).toUpperCase(Localization.getLocale());
-        } else {
-            return "";
-        }
+        return RenderUtils.fetchValue(template, differentiator).toUpperCase(Localization.getLocale());
     }
 }

lib/src/test/java/rife/render/TestCase.java

@@ -0,0 +1,40 @@
+/*
+ *  Copyright 2023 the original author or authors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+package rife.render;
+
+import org.junit.jupiter.api.Test;
+import rife.template.TemplateFactory;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class TestCase {
+    @Test
+    void testCapitalize() {
+        var t = TemplateFactory.TXT.get("capitalize");
+        t.setAttribute("foo", "this is a test");
+        assertThat(t.getContent()).isEqualTo("This is a test");
+    }
+
+    @Test
+    void testLowercase() {
+        var t = TemplateFactory.TXT.get("lowercase");
+        var bean = new ValueBean("this IS a TEST");
+        t.setBean(bean);
+        assertThat(t.getContent()).isEqualTo(bean.getValue() + ": this is a test");
+    }
+}

lib/src/test/java/rife/render/TestEncode.java

@@ -17,17 +17,48 @@
 
 package rife.render;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import rife.template.TemplateFactory;
 
 import static org.assertj.core.api.Assertions.assertThat;
+
 class TestEncode {
+    public static final String FOO = "foo";
+
+    @Test
+    void testEncodeBase64() {
+        var t = TemplateFactory.TXT.get("base64");
+        t.setValue(FOO, "This is a test");
+        assertThat(t.getContent()).isEqualTo(t.getValue(FOO) + ": VGhpcyBpcyBhIHRlc3Q=");
+    }
+
+    @Test
+    void testEncodeHtml() {
+        var t = TemplateFactory.HTML.get("encodeHtml");
+        t.setAttribute(FOO, "<a test &>");
+        assertThat(t.getContent()).isEqualTo("&lt;a test &amp;&gt;");
+    }
+
+    @Test
+    void testEncodeRot13() {
+        var t = TemplateFactory.TXT.get("rot13");
+        var value = "This is a test";
+        var rot13 = "Guvf vf n grfg";
+
+        // Encode
+        var bean = new ValueBean(value);
+        t.setBean(bean);
+        assertThat(t.getContent()).isEqualTo(bean.getValue() + ": " + rot13);
+
+        // Decode
+        t.setValue("value", rot13);
+        assertThat(t.getContent()).isEqualTo(rot13 + ": " + value);
+    }
+
     @Test
     void testEncodeUrl() {
         var t = TemplateFactory.HTML.get("encodeUrl");
-        t.setAttribute("foo", "a test &");
-        var encodedValue = "a%20test%20%26";
-        assertThat(t.getContent()).isEqualTo(encodedValue + "<br>\n" + encodedValue);
+        t.setAttribute(FOO, "a test &");
+        assertThat(t.getContent()).isEqualTo("<a href=\"https://example.com/a%20test%20%26\">a test &amp;</a>");
     }
 }

lib/src/test/resources/templates/base64.txt

@@ -0,0 +1 @@
+{{v foo/}}: {{v render:rife.render.EncodeBase64:foo/}}

lib/src/test/resources/templates/capitalize.txt

@@ -0,0 +1 @@
+{{v render:rife.render.Capitalize:foo/}}

lib/src/test/resources/templates/encodeHtml.html

@@ -0,0 +1 @@
+<!--v render:rife.render.EncodeHtml:foo/-->

lib/src/test/resources/templates/encodeUrl.html

@@ -1,3 +1 @@
-<!--v render:rife.render.EncodeUrl:foo/--><br>
-{{v render:rife.render.EncodeUrl:foo/}}
-{{v foo/}}
+<a href="https://example.com/{{v render:rife.render.EncodeUrl:foo/}}">{{v render:rife.render.EncodeHtml:foo/}}</a>

lib/src/test/resources/templates/lowercase.txt

@@ -0,0 +1 @@
+{{v value/}}: {{v render:rife.render.Lowercase:value/}}

lib/src/test/resources/templates/rot13.txt

@@ -0,0 +1 @@
+{{v value/}}: {{v render:rife.render.Rot13:value/}}