[cdp] Add the ability to listen for page mutations

Note, this is a pretty rubbish implementation, and needs to be made more robust, but it suffices to show that the idea works.
SeleniumHQ · Aug 18, 2020 · 65f0ae8 · 65f0ae8
1 parent 74f3b22
commit 65f0ae8
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diff --git a/java/client/src/org/openqa/selenium/devtools/events/CdpEventTypes.java b/java/client/src/org/openqa/selenium/devtools/events/CdpEventTypes.java
@@ -17,16 +17,32 @@
 
 package org.openqa.selenium.devtools.events;
 
+import com.google.common.base.Joiner;
+import org.openqa.selenium.By;
+import org.openqa.selenium.JavascriptExecutor;
+import org.openqa.selenium.WebDriver;
+import org.openqa.selenium.WebElement;
 import org.openqa.selenium.devtools.DevTools;
 import org.openqa.selenium.devtools.HasDevTools;
 import org.openqa.selenium.internal.Require;
+import org.openqa.selenium.json.Json;
 import org.openqa.selenium.logging.EventType;
 import org.openqa.selenium.logging.HasLogEvents;
 
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.WeakHashMap;
 import java.util.function.Consumer;
 
+import static org.openqa.selenium.json.Json.MAP_TYPE;
+
 public class CdpEventTypes {
 
+  private static final WeakHashMap<WebDriver, Set<String>> PINNED_SCRIPTS = new WeakHashMap<>();
+  private static final Json JSON = new Json();
+
   private CdpEventTypes() {
     // Utility class.
   }
@@ -56,4 +72,97 @@ public void initializeLogger(HasLogEvents loggable) {
     };
   }
 
+  public static EventType<Void> domMutation(Consumer<DomMutationEvent> handler) {
+    String script = Joiner.on("\n").join(new String[]{
+      "(function() {",
+      "const observer = new MutationObserver((mutations) => {",
+      "  for (const mutation of mutations) {",
+      "    switch (mutation.type) {",
+      "      case \"attributes\":",
+      // Don't report our own attribute has changed.
+      "        if (mutation.attributeName == 'data-__webdriver_id') {",
+      "          break;",
+      "        }",
+      "        const curr = mutation.target.getAttribute(mutation.attributeName);",
+      "        var id = mutation.target.dataset.__webdriver_id",
+      "        if (!id) {",
+      "          id = Math.random().toString(36).substring(2) + Date.now().toString(36);",
+      "          mutation.target.dataset.__webdriver_id = id;",
+      "        }",
+      "        const json = JSON.stringify({",
+      "          \"target\": id,",
+      "          \"name\": mutation.attributeName,",
+      "          \"value\": curr,",
+      "          \"oldValue\": mutation.oldValue",
+      "        });",
+      "        __webdriver_attribute(json);",
+      "        break;",
+      "      default:",
+      "        break;",
+      "    }",
+      "  }",
+      "});",
+      "observer.observe(document, {",
+      "  \"attributes\": true,",
+      "  \"attributeOldValue\": true,",
+      "  \"characterData\": true,",
+      "  \"characterDataOldValue\": true,",
+      "  \"childList\": true,",
+      "  \"subtree\": true",
+      "});",
+      "})();"
+    });
+
+    return new EventType<Void>() {
+      @Override
+      public void consume(Void event) {
+        handler.accept(null);
+      }
+
+      @Override
+      public void initializeLogger(HasLogEvents loggable) {
+        Require.precondition(loggable instanceof WebDriver, "Loggable must be a WebDriver");
+        Require.precondition(loggable instanceof HasDevTools, "Loggable must implement HasDevTools");
+
+        DevTools tools = ((HasDevTools) loggable).getDevTools();
+        tools.createSession();
+
+        WebDriver driver = (WebDriver) loggable;
+        Set<String> scripts = PINNED_SCRIPTS.computeIfAbsent(driver, ignored -> new HashSet<>());
+        if (!scripts.contains(script)) {
+          // Pin the script
+          tools.send(tools.getDomains().runtime().enable());
+          tools.send(tools.getDomains().runtime().addBinding("__webdriver_attribute"));
+
+          tools.send(tools.getDomains().page().enable());
+          tools.send(tools.getDomains().page().addScriptToEvaluateOnNewDocument(script));
+
+          // And add the script to the current page
+          ((JavascriptExecutor) driver).executeScript(script);
+
+          scripts.add(script);
+        }
+
+        tools.addListener(
+          tools.getDomains().runtime().bindingCalled(),
+          bindingCalled -> {
+            Map<String, Object> values = JSON.toType(bindingCalled.getPayload(), MAP_TYPE);
+            String id = (String) values.get("target");
+
+            List<WebElement> elements = driver.findElements(By.cssSelector(String.format("*[data-__webdriver_id='%s']", id)));
+
+            if (!elements.isEmpty()) {
+              DomMutationEvent event = new DomMutationEvent(
+                elements.get(0),
+                String.valueOf(values.get("name")),
+                String.valueOf(values.get("value")),
+                String.valueOf(values.get("oldValue")));
+              handler.accept(event);
+            }
+          }
+        );
+      }
+    };
+  }
+
 }
diff --git a/java/client/src/org/openqa/selenium/devtools/events/DomMutationEvent.java b/java/client/src/org/openqa/selenium/devtools/events/DomMutationEvent.java
@@ -0,0 +1,34 @@
+package org.openqa.selenium.devtools.events;
+
+import org.openqa.selenium.WebElement;
+
+public class DomMutationEvent {
+
+  private final WebElement element;
+  private final String attributeName;
+  private final String currentValue;
+  private final String oldValue;
+
+  public DomMutationEvent(WebElement element, String attributeName, String currentValue, String oldValue) {
+    this.element = element;
+    this.attributeName = attributeName;
+    this.currentValue = currentValue;
+    this.oldValue = oldValue;
+  }
+
+  public WebElement getElement() {
+    return element;
+  }
+
+  public String getAttributeName() {
+    return attributeName;
+  }
+
+  public String getCurrentValue() {
+    return currentValue;
+  }
+
+  public String getOldValue() {
+    return oldValue;
+  }
+}
diff --git a/java/client/src/org/openqa/selenium/devtools/idealized/Domains.java b/java/client/src/org/openqa/selenium/devtools/idealized/Domains.java
@@ -19,6 +19,7 @@
 
 import org.openqa.selenium.devtools.idealized.fetch.Fetch;
 import org.openqa.selenium.devtools.idealized.log.Log;
+import org.openqa.selenium.devtools.idealized.page.Page;
 import org.openqa.selenium.devtools.idealized.runtime.RuntimeDomain;
 import org.openqa.selenium.devtools.idealized.target.Target;
 
@@ -33,6 +34,8 @@ public interface Domains {
 
   Log log();
 
+  Page page();
+
   Target target();
 
   RuntimeDomain runtime();

diff --git a/java/client/src/org/openqa/selenium/devtools/idealized/page/Page.java b/java/client/src/org/openqa/selenium/devtools/idealized/page/Page.java
@@ -0,0 +1,12 @@
+package org.openqa.selenium.devtools.idealized.page;
+
+import org.openqa.selenium.devtools.Command;
+import org.openqa.selenium.devtools.idealized.page.model.ScriptIdentifier;
+
+public interface Page {
+
+  Command<Void> enable();
+
+  Command<ScriptIdentifier> addScriptToEvaluateOnNewDocument(String source);
+
+}
diff --git a/java/client/src/org/openqa/selenium/devtools/idealized/page/model/ScriptIdentifier.java b/java/client/src/org/openqa/selenium/devtools/idealized/page/model/ScriptIdentifier.java
@@ -0,0 +1,17 @@
+package org.openqa.selenium.devtools.idealized.page.model;
+
+import org.openqa.selenium.internal.Require;
+
+public class ScriptIdentifier {
+
+  private final Object actualIdentifier;
+
+  public ScriptIdentifier(Object actualIdentifier) {
+    this.actualIdentifier = Require.nonNull("Actual identifier", actualIdentifier);
+  }
+
+  public Object getActualIdentifier() {
+    return actualIdentifier;
+  }
+
+}
diff --git a/java/client/src/org/openqa/selenium/devtools/idealized/runtime/RuntimeDomain.java b/java/client/src/org/openqa/selenium/devtools/idealized/runtime/RuntimeDomain.java
@@ -19,11 +19,16 @@
 
 import org.openqa.selenium.devtools.Command;
 import org.openqa.selenium.devtools.Event;
+import org.openqa.selenium.devtools.idealized.runtime.model.BindingCalled;
 import org.openqa.selenium.devtools.idealized.runtime.model.ConsoleAPICalled;
 
 public interface RuntimeDomain {
 
   Command<Void> enable();
 
   Event<ConsoleAPICalled> consoleAPICalled();
+
+  Command<Void> addBinding(String webdriver_attribute);
+
+  Event<BindingCalled> bindingCalled();
 }
diff --git a/java/client/src/org/openqa/selenium/devtools/idealized/runtime/model/BindingCalled.java b/java/client/src/org/openqa/selenium/devtools/idealized/runtime/model/BindingCalled.java
@@ -0,0 +1,30 @@
+package org.openqa.selenium.devtools.idealized.runtime.model;
+
+import org.openqa.selenium.internal.Require;
+
+public class BindingCalled {
+
+  private final String name;
+  private final String payload;
+
+  public BindingCalled(String name, String payload) {
+    this.name = Require.nonNull("Name", name);
+    this.payload = Require.nonNull("Payload", payload);
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public String getPayload() {
+    return payload;
+  }
+
+  @Override
+  public String toString() {
+    return "BindingCalled{" +
+      "name='" + name + '\'' +
+      ", payload='" + payload + '\'' +
+      '}';
+  }
+}
diff --git a/java/client/src/org/openqa/selenium/devtools/noop/NoOpDomains.java b/java/client/src/org/openqa/selenium/devtools/noop/NoOpDomains.java
@@ -21,6 +21,7 @@
 import org.openqa.selenium.devtools.idealized.Domains;
 import org.openqa.selenium.devtools.idealized.fetch.Fetch;
 import org.openqa.selenium.devtools.idealized.log.Log;
+import org.openqa.selenium.devtools.idealized.page.Page;
 import org.openqa.selenium.devtools.idealized.runtime.RuntimeDomain;
 import org.openqa.selenium.devtools.idealized.target.Target;
 
@@ -44,6 +45,11 @@ public Log log() {
     throw new DevToolsException(WARNING);
   }
 
+  @Override
+  public Page page() {
+    throw new DevToolsException(WARNING);
+  }
+
   @Override
   public RuntimeDomain runtime() {
     throw new DevToolsException(WARNING);

diff --git a/java/client/src/org/openqa/selenium/devtools/v84/V84Domains.java b/java/client/src/org/openqa/selenium/devtools/v84/V84Domains.java
@@ -20,6 +20,7 @@
 import org.openqa.selenium.devtools.idealized.Domains;
 import org.openqa.selenium.devtools.idealized.fetch.Fetch;
 import org.openqa.selenium.devtools.idealized.log.Log;
+import org.openqa.selenium.devtools.idealized.page.Page;
 import org.openqa.selenium.devtools.idealized.runtime.RuntimeDomain;
 import org.openqa.selenium.devtools.idealized.target.Target;
 
@@ -34,6 +35,11 @@ public Log log() {
     return new V84Log();
   }
 
+  @Override
+  public Page page() {
+    throw new UnsupportedOperationException("page");
+  }
+
   @Override
   public RuntimeDomain runtime() {
     return new V84Runtime();

diff --git a/java/client/src/org/openqa/selenium/devtools/v84/V84Runtime.java b/java/client/src/org/openqa/selenium/devtools/v84/V84Runtime.java
@@ -21,12 +21,15 @@
 import org.openqa.selenium.devtools.Command;
 import org.openqa.selenium.devtools.Event;
 import org.openqa.selenium.devtools.idealized.runtime.RuntimeDomain;
+import org.openqa.selenium.devtools.idealized.runtime.model.BindingCalled;
 import org.openqa.selenium.devtools.idealized.runtime.model.RemoteObject;
+import org.openqa.selenium.devtools.v84.runtime.Runtime;
 import org.openqa.selenium.devtools.v84.runtime.model.ConsoleAPICalled;
 
 import java.math.BigDecimal;
 import java.time.Instant;
 import java.util.List;
+import java.util.Optional;
 
 public class V84Runtime implements RuntimeDomain {
   @Override
@@ -56,4 +59,22 @@ public Event<org.openqa.selenium.devtools.idealized.runtime.model.ConsoleAPICall
       }
     );
   }
+
+  @Override
+  public Command<Void> addBinding(String name) {
+    return Runtime.addBinding(name, Optional.empty());
+  }
+
+  @Override
+  public Event<BindingCalled> bindingCalled() {
+    return new Event<BindingCalled>(
+      org.openqa.selenium.devtools.v84.runtime.Runtime.bindingCalled().getMethod(),
+      input -> {
+        org.openqa.selenium.devtools.v84.runtime.model.BindingCalled res = input.read(
+          org.openqa.selenium.devtools.v84.runtime.model.BindingCalled.class);
+
+        return new BindingCalled(res.getName(), res.getPayload());
+      }
+    );
+  }
 }
diff --git a/java/client/src/org/openqa/selenium/devtools/v85/V85Domains.java b/java/client/src/org/openqa/selenium/devtools/v85/V85Domains.java
@@ -20,6 +20,7 @@
 import org.openqa.selenium.devtools.idealized.Domains;
 import org.openqa.selenium.devtools.idealized.fetch.Fetch;
 import org.openqa.selenium.devtools.idealized.log.Log;
+import org.openqa.selenium.devtools.idealized.page.Page;
 import org.openqa.selenium.devtools.idealized.runtime.RuntimeDomain;
 import org.openqa.selenium.devtools.idealized.target.Target;
 
@@ -34,6 +35,11 @@ public Log log() {
     return new V85Log();
   }
 
+  @Override
+  public Page page() {
+    return new V85Page();
+  }
+
   @Override
   public RuntimeDomain runtime() {
     return new V85Runtime();

diff --git a/java/client/src/org/openqa/selenium/devtools/v85/V85Page.java b/java/client/src/org/openqa/selenium/devtools/v85/V85Page.java
@@ -0,0 +1,36 @@
+package org.openqa.selenium.devtools.v85;
+
+import com.google.common.collect.ImmutableMap;
+import org.openqa.selenium.devtools.Command;
+import org.openqa.selenium.devtools.ConverterFunctions;
+import org.openqa.selenium.devtools.idealized.page.Page;
+import org.openqa.selenium.devtools.v85.page.model.ScriptIdentifier;
+import org.openqa.selenium.internal.Require;
+import org.openqa.selenium.json.JsonInput;
+
+import java.util.function.Function;
+
+public class V85Page implements Page {
+
+  @Override
+  public Command<Void> enable() {
+    return org.openqa.selenium.devtools.v85.page.Page.enable();
+  }
+
+  @Override
+  public Command<org.openqa.selenium.devtools.idealized.page.model.ScriptIdentifier> addScriptToEvaluateOnNewDocument(String source) {
+    Require.nonNull("Source", source);
+    ImmutableMap.Builder<String, Object> params = ImmutableMap.builder();
+    params.put("source", source);
+
+    Function<JsonInput, ScriptIdentifier> mapper = ConverterFunctions.map("identifier", ScriptIdentifier.class);
+
+    return new Command<>(
+      "Page.addScriptToEvaluateOnNewDocument",
+      ImmutableMap.of("source", source),
+      input -> {
+        ScriptIdentifier actualId = mapper.apply(input);
+        return new org.openqa.selenium.devtools.idealized.page.model.ScriptIdentifier(actualId);
+      });
+  }
+}