Merge "docs: update web page debugging with info about page and line numbering...

<pre class="no-pretty-print">

I/MyActivity( 1557): MyClass.getView() — get item number 1

</pre>

      <p>Logcat is also the place to look when debugging a web page in the Android browser. All

browser bugs will be output to logcat with the {@code WebCore} tag.

      <p>Logcat is also the place to look when debugging a web page in the Android Browser app. See

<a href="#DebuggingWebPages">Debugging Web Pages</a> below.</p>

</dl>

<p>For more information about all the development tools provided with the Android SDK, see the <a

<h2 id="DebuggingWebPages">Debugging Web Pages</h2>

<p>If you're developing a web application for Android devices, you can debug your JavaScript on

Android using the Console APIs, which will output messages to logcat. If you're familiar

<p>If you're developing a web application for Android devices, you can debug your JavaScript in the

Android Browser using the Console APIs, which will output messages to logcat. If you're familiar

debugging web pages with Firefox's FireBug or WebKit's Web Inspector, then you're probably familiar

with the Console APIs. The Android Browser (and {@link android.webkit.WebChromeClient}) supports

with the Console APIs. The Android Browser (and the {@link android.webkit.WebChromeClient}) supports

most of the same APIs.</p>

<p>When you call a function from the Console APIs (in the DOM's {@code window.console} object),

</pre>

<p>Then the logcat output from the Android Browser will look like this:</p>

<pre class="no-pretty-print">

W/browser ( 202): Console: Hello World :0

W/browser ( 202): Console: Hello World http://www.example.com/hello.html :82

</pre>

<p class="note"><strong>Note:</strong> All Console messages from the Android

Browser are tagged with the name "browser" on Android platforms running API Level 7 or higher and

tagged with the name "WebCore" for platforms running API Level 6 or lower.</p>

<p>Not all of the Console APIs available in Firefox or other WebKit browsers are implemented

on Android. Mostly, you need to depend on basic text logging provided by

functions like {@code console.log(String)}, {@code console.info(String)}, {@code

console.warn(String)}, and {@code console.error(String)}. Although other Console functions may not

be implemented, they will not raise run-time errors, but will simply not behave as you might

expect.</p>

<p>All Console messages from the Android Browser are tagged with the name "browser" on Android

platforms running API Level 7 or higher. On platforms running API Level 6 or lower, Browser

messages are tagged with the name "WebCore". The Android Browser also formats console messages

with the log message

preceded by "Console:" and then followed by the address and line number where the

message occurred. (The format for the address and line number will appear different from the example

above on platforms running API Level 6 or lower.)</p>

<p>The Android Browser (and {@link android.webkit.WebChromeClient}) does not implement all of the

Console APIs provided by Firefox or other WebKit-based browsers. Primarily, you need to depend

on the basic text logging functions:</p>

<ul>

  <li>{@code console.log(String)}</li>

  <li>{@code console.info(String)}</li>

  <li>{@code console.warn(String)}</li>

  <li>{@code console.error(String)}</li>

</ul>

<p>Although the Android Browser may not fully implement other Console functions, they will not raise

run-time errors, but may not behave the same as they do on other desktop browsers.</p>

<p>If you've implemented a custom {@link android.webkit.WebView} in your application, then in order

to receive messages that are sent through the Console APIs, you must provide a {@link

<pre>

myWebView.setWebChromeClient(new WebChromeClient() {

  public void onConsoleMessage(String message, int lineNumber, String sourceID) {

    Log.d("MyApplication", message);

    Log.d("MyApplication", message + " -- From line " + lineNumber + " of " + sourceID);

  }

});

</pre>

<p>When the "Hello World" log is executed through your {@link android.webkit.WebView}, it will

now look like this:</p>

<pre class="no-pretty-print">

D/MyApplication ( 430): Hello World

D/MyApplication ( 430): Hello World -- From line 82 of http://www.example.com/hello.html

</pre>

<p class="note"><strong>Note:</strong> The {@link

android.webkit.WebChromeClient#onConsoleMessage(String,int,String) onConsoleMessage()} callback

method was added with API Level 7. If you are targetting platforms running API Level 6 or lower,

then your Console messages will automatically be sent to logcat with the "WebCore" logging tag.</p>

method was added with API Level 7. If you are using a custom {@link

android.webkit.WebView} on a platform running API Level 6 or lower, then your Console messages will

automatically be sent to logcat with the "WebCore" logging tag.</p>