basic js model

Author: Osiris-Team

README.md

@@ -4,7 +4,8 @@ A headless browser for Java.
 ## IN-DEV | CONTRIBUTIONS NEEDED!
 To simulate a browser nowadays we need to provide all of these web apis: https://developer.mozilla.org/en-US/docs/Web/API
 See package `com.osiris.headlessbrowser.javascript` for already implemented apis.
-If you are working on a implementation open an issue to keep track of who is working on what and avoid duplicate work.
+If you are working on an implementation open an issue to keep track of who is working on what and avoid duplicate work.
+[Read this to get started.](how-to-implement-a-js-web-api.md)
 
 ## Motivation
 There are only two types of headless Java browsers currently available:

RESEARCH.md

@@ -0,0 +1,21 @@
+# Research
+Organized list containing easy to forget things.
+
+## GraalJS - JavaScript Engine
+Problem: `eval()` fails to detect correct binding when nested classes are used (at least in tests).
+
+```java
+import com.osiris.headlessbrowser.javascript.JavaScriptAPI;
+
+public class JS_API_Test extends JavaScriptAPI {
+    // stuff...
+    class NestedObject {
+    }
+
+    @Override
+    public Object getObject() {
+        return new NestedObject();
+    }
+}
+```
+Fix: Simply don't use nested classes/objects.

how-to-implement-a-js-web-api.md

@@ -0,0 +1,7 @@
+# How to implement a JavaScript Web-API
+
+1. Simply copy the `JS_API_Console` class from the `com.osiris.headlessbrowser.javascript` package 
+   and paste it with another name into the same package.
+2. Register your new class in the `JSContext` class, so it gets loaded into it.
+3. The `JS_API_Console` is the Java-Implementation of the JavaScript console api and
+   thus provides all the information you need to start implementing a new web-api.

src/main/java/com/osiris/headlessbrowser/JSContext.java

@@ -1,7 +1,7 @@
 package com.osiris.headlessbrowser;
 
 import com.osiris.headlessbrowser.javascript.JS_API_Console;
-import com.osiris.headlessbrowser.javascript.defaults.JavaScriptAPI;
+import com.osiris.headlessbrowser.javascript.JavaScriptAPI;
 import com.osiris.headlessbrowser.javascript.exceptions.DuplicateRegisteredId;
 import de.undercouch.citeproc.VariableWrapper;
 import de.undercouch.citeproc.VariableWrapperParams;
@@ -20,33 +20,34 @@
 public class JSContext extends AbstractScriptRunner {
     private HeadlessWindow window;
     private Context rawContext = Context.newBuilder("js").allowAllAccess(true).build();
-    private List<JavaScriptAPI> loadedJSWebAPIs = new ArrayList<>();
+    private Map<JavaScriptAPI, Boolean> loadedJSWebAPIs = new HashMap<>();
 
     public JSContext(HeadlessWindow window) {
         this.window = window;
 
         // APIs in this list get loaded into this JSContext in the order they were added to this list.
         // If you want to add an api that depends on another one make sure to add it after that one.
         //loadedJSWebAPIs.add(new JS_API_Console(System.out));
-        rawContext.getBindings("js").getMemberKeys().forEach(key -> System.out.println(key));
+        loadedJSWebAPIs.put(new JS_API_Console(System.out), true); // If true overrides any existing variable with the same name
 
         // Register all JavaScript Web-APIs:
-        try{
-            for (JavaScriptAPI api :
-                    loadedJSWebAPIs) {
-                registerAndLoad(api.getJSVarName(), api.getObject());
+        loadedJSWebAPIs.forEach((api, override) -> {
+            try{
+                registerAndLoad(api.getJSVarName(), api.getObject(), override);
+            } catch (Exception exception) {
+                System.err.println("Failed to load one/multiple JavaScript Web-API(s) into the current JavaScript-Context! Details:");
+                throw new RuntimeException(exception);
             }
-        } catch (Exception exception) {
-            System.err.println("Failed to load one/multiple JavaScript Web-API(s) into the current JavaScript-Context! Details:");
-            throw new RuntimeException(exception);
-        }
+        });
+
     }
 
     /**
      * Registers and loads this API into the provided {@link JSContext}. <br>
+     * @param id
      */
-    public void registerAndLoad(String id, Object object) throws DuplicateRegisteredId, IOException {
-        if(rawContext.getBindings("js").getMember(id) != null)
+    public void registerAndLoad(String id, Object object, boolean override) throws DuplicateRegisteredId, IOException {
+        if(!override && rawContext.getBindings("js").getMember(id) != null)
             throw new DuplicateRegisteredId("Failed to register because of already existing/registered id '"+id+"'.");
         rawContext.getBindings("js").putMember(id, object);
     }
@@ -60,11 +61,11 @@ public void registerAndLoad(String id, Object object) throws DuplicateRegistered
      * @throws IOException
      */
     public void eval(String jsCode) throws IOException {
-        eval(new BufferedReader(new StringReader(jsCode)));
+        rawContext.eval("js", jsCode);
     }
 
     public void eval(InputStream jsCodesInputStream) throws IOException {
-        eval(new BufferedReader(new InputStreamReader(jsCodesInputStream)));
+        eval(new InputStreamReader(jsCodesInputStream));
     }
 
     public HeadlessWindow getWindow() {
@@ -95,6 +96,14 @@ public String getVersion() {
 
     @Override
     public void eval(Reader reader) throws IOException {
+        String jsCode = null;
+        try (BufferedReader bufferedReader = new BufferedReader(reader)) {
+            while ((jsCode = bufferedReader.readLine()) != null) {
+                jsCode = jsCode+jsCode;
+            }
+        } catch (IOException e) {
+            throw e;
+        }
         rawContext.eval(Source.newBuilder("js", reader, null).cached(false).build());
     }
 

src/main/java/com/osiris/headlessbrowser/javascript/JS_API_Console.java

@@ -1,8 +1,5 @@
 package com.osiris.headlessbrowser.javascript;
 
-import com.osiris.headlessbrowser.javascript.defaults.Default_JS_API;
-import com.osiris.headlessbrowser.javascript.defaults.JavaScriptAPI;
-
 import java.io.OutputStream;
 import java.io.PrintStream;
 
@@ -11,12 +8,13 @@
  * WORK IN PROGRESS <br>
  * @author Osiris-Team
  */
-public class JS_API_Console extends Default_JS_API implements JavaScriptAPI {
+public class JS_API_Console implements JavaScriptAPI {
     private PrintStream out;
 
     public JS_API_Console(OutputStream out) {
         this(new PrintStream(out));
     }
+
     public JS_API_Console(PrintStream out) {
         this.out = out;
     }
@@ -31,10 +29,12 @@ public String getJSVarName() {
 
     @Override
     public Object getObject() {
-        return new Console();
+        return this;
     }
 
-    class Console{
+    public void log(String msg){
+        out.println(msg);
+    }
         /*
         TODO IMPLEMENT THESE
         TODO GENERATE TEST FOR EACH METHOD.
@@ -69,10 +69,4 @@ class Console{
 };
          */
 
-        public void log(String msg){
-            out.println(msg);
-        }
-    }
-
-
 }

src/main/java/com/osiris/headlessbrowser/javascript/JavaScriptAPI.java

@@ -0,0 +1,22 @@
+package com.osiris.headlessbrowser.javascript;
+
+import com.osiris.headlessbrowser.JSContext;
+
+import java.io.InputStream;
+
+public interface JavaScriptAPI {
+
+    /**
+     * The global variable name used in the JavaScript code to access the APIs methods/functions. <br>
+     * Example: console.log('Hello'); <br>
+     * JSVarName: console <br>
+     * Should be unique. <br>
+     */
+    String getJSVarName();
+
+    /**
+     * The object containing all methods/functions of the API. <br>
+     */
+    Object getObject();
+
+}

src/main/java/com/osiris/headlessbrowser/javascript/defaults/Default_JS_API.java

@@ -22,10 +22,10 @@ void testCallMethods() throws ScriptRunnerException, IOException {
     }
 
     @Test
-    void testContextWebApis() {
+    void testContextWebApis() throws IOException {
         HeadlessBrowser browser = new HeadlessBrowser();
         JSContext jsContext = browser.openNewWindow().getJsContext();
-        jsContext.getRawContext().getBindings("js").getMemberKeys().forEach(System.out::println);
+        jsContext.eval("console.log('hi!');");
     }
 
     public static class MyClass {