Added EncodeJS

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

@@ -0,0 +1,74 @@
+/*
+ *  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.template.ValueRenderer;
+import rife.tools.StringUtils;
+
+/**
+ * <p>Encodes a template value to JavaScript/ECMAScript.</p>
+ *
+ * <p>Usage:</p>
+ *
+ * <pre>
+ *   &lt;!--v render:rife.render.EncodeJS:valueId/--&gt;
+ *   {{v render:rife.render.EncodeJS:valueId/}}
+ * </pre>
+ *
+ * @author <a href="https://erik.thauvin.net/">Erik C. Thauvin</a>
+ * @see StringUtils#encodeJson(String)
+ * @since 1.0
+ */
+public class EncodeJS implements ValueRenderer {
+    /**
+     * Encodes a string to JavaScript/ECMAScript.
+     *
+     * @param src the source string.
+     * @return the enocded string
+     */
+    public static String encodeJS(String src) {
+        if (src == null || src.isBlank()) {
+            return src;
+        }
+
+        var sb = new StringBuilder();
+        var len = src.length();
+
+        char c;
+        for (var i = 0; i < len; i++) {
+            c = src.charAt(i);
+            switch (c) {
+                case '\'' -> sb.append("\\'");
+                case '"' -> sb.append("\\\"");
+                case '\\' -> sb.append("\\\\");
+                case '/' -> sb.append("\\/");
+                default -> sb.append(c);
+            }
+        }
+        return sb.toString();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public String render(Template template, String valueId, String differentiator) {
+        return encodeJS(RenderUtils.fetchValue(template, differentiator));
+    }
+}