Allow exlusion rules to contain JavaScript.

wayback-core/src/main/java/org/archive/wayback/replay/html/rewrite/ScriptRewritingStringTransformer.java

@@ -0,0 +1,92 @@
+package org.archive.wayback.replay.html.rewrite;
+
+import java.util.StringTokenizer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+
+import org.apache.commons.lang.StringEscapeUtils;
+import org.archive.wayback.replay.html.ReplayParseContext;
+
+public class ScriptRewritingStringTransformer extends
+        RewritingStringTransformer {
+
+    private ScriptEngine scriptEngine = null;
+    private static final ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
+
+    private static final Logger LOGGER = Logger.getLogger(ScriptRewritingStringTransformer.class.getName());
+
+    private String scriptEngineType = null;    
+
+    protected void initScriptEngine() {
+        if (scriptEngine == null) {
+            scriptEngine = scriptEngineManager.getEngineByName(scriptEngineType);
+
+            if (scriptEngine == null) {
+                LOGGER.log(Level.SEVERE, "Could not create a scriptEngine of type: " + scriptEngineType + "! Rewriting will be disabled for this rewriter!");
+            }
+        }
+    }
+
+    public String getScriptEngineType() {
+        return scriptEngineType;
+    }
+
+    public void setScriptEngineType(String scriptEngineType) {
+        this.scriptEngineType = scriptEngineType;
+    }
+
+
+    @Override
+    public String transform(ReplayParseContext rpContext, String input) {
+
+        initScriptEngine();
+
+        if (scriptEngine == null) {
+            return input;
+        }
+
+        if (!rpContext.isInScriptText() && !rpContext.isInJS()) {
+            return input;
+        }
+
+        String policy = rpContext.getOraclePolicy();
+
+        if (policy == null) {
+            return input;
+        }
+
+        if (policy.startsWith(scriptEngineType.toLowerCase() + ":")) {
+            String script = parseScriptFromPolicy(policy);
+
+            if (script == null) {
+                LOGGER.log(Level.SEVERE, "Could not find script code in policy: " + policy + "! Script engine is type: " + scriptEngineType);
+            }
+
+            try {
+                scriptEngine.eval("var content='" + StringEscapeUtils.escapeJavaScript(input) + "'; ");
+                scriptEngine.eval(script);
+                input = (String)scriptEngine.get("content");
+            }
+            catch (ScriptException se) {
+                LOGGER.log(Level.SEVERE, "Error executing script: " + script.toString() + "! Script engine is type: " + scriptEngineType, se);
+            }
+        }
+
+        return input;
+    }
+
+    protected String parseScriptFromPolicy(String policy) {
+
+        if (policy != null) {
+            if (policy.startsWith(scriptEngineType.toLowerCase() + ":")) {
+                return policy.substring(policy.indexOf(":") + 1);
+            }
+        }
+
+        return null;
+    }
+}