![]() After all, JavaScript is dynamic, and so it’s output is constantly changing. And it can do lots of things, but it’s most important function is to provide feedback about JavaScript code as it is executing. That functionality is known as a console. To demo the capabilities of the language, Eich opened up a browser, typed a JavaScript command into its address bar, and an alert window popped up in a custom frameset, in a crude example of what would eventually be known as a JavaScript console.Īs a page renders and changes based on the code that’s written, output and errors can be logged directly to text and output onto the webpage itself. The first example of debugging JavaScript is also the first example of JavaScript’s public use. JavaScript’s creator, Brendan Eich, understood this well. But when JavaScript was first adopted by Netscape, it required something different. It also became one of the earliest ways for developers to verify changes or issues on their site. By making any webpage ostensibly open by default, web developers were able to get their start simply by hopping from page to page and taking a look at the code directly. If not for that simple tool, many developers would have had no way to break into web development themselves. The ability to view source was available in some of the earliest web browsers. A new window will appear that displays that page’s code, the raw HTML and CSS. Go to any page on the web and find View Source in your toolbar and you will be magically transported under the hood of a website. In fact, being able to debug the languages of the web can trace its roots back to the earliest days of the web. It was a transformative moment for the web, but it was also a long time coming. Web debugging and monitoring was all grown up. The days of fly-by-the-seat-of-your-pants debugging were over. The Webkit version was called Web Inspector. Three days later, Webkit contributor Timothy Hatcher checked in a bit of code that added something similar to Webkit browsers like Apple’s Safari. It was called Firebug, an extension of Mozilla that allowed developers to more easily debug the JavaScript and HTML of their webpages. On January 12, Joe Hewitt-a programmer with almost a decade of experience on the web as one of the original contributors at Netscape to the Firefox browser-announced something new he was working on. January of 2006 was a big month for web developers. They came from the smallest places, and it took years to get them where they are today. ![]() DOM objects) that you want to inspect the current value of, and the value will be displayed.If you’re a developer today, you likely take advantage of built in tools for web debugging every day. ![]() ![]() Here you can type in any variables or objects (e.g. Also, you can use the ‘console’ tab to view any errors (which will be shown in red), or at the bottom of the console you’ll see a ‘>’ prompt.You can add breakpoints in the JavaScript that allow you to debug your code. Select the ‘sources’ tab of the Chrome developer tools to view JavaScript that your Cordova app on the device/emulator is currently running.This brings up the Chrome developer tools that now allow you to debug your application. Click the ‘inspect’ link under the ‘WebView’ section where you see your device/emulator listed.Your device/emulator will be displayed along with any other recognised devices that are connected to your computer, and under your device there will be details of the Cordova ‘WebView’ (basically your Cordova app), which is running on the device/emulator (the way Cordova works is that it basically creates a ‘browser’ window on your device/emulator, within which there is a ‘WebView’ which is your running HTML/JavaScript app).In Chrome on your desktop computer, enter chrome://inspect/#devices in the address bar.Run your Cordova application on the device or emulator.Or, if you’re using Cordova 3.3+ and don’t have a physical device with 4.4, you can use an emulator that uses Android 4.4+ to run the application through the emulator, on your desktop computer. Enable USB debugging on your device (on my device this is under Settings > More > Developer options > USB debugging).Plug the device into your desktop computer using a USB cable.If you’re using Cordova 3.3 or higher and your device is running Android 4.4 or higher you can use ‘Remote Debugging on Android with Chrome’.
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