#Html iframe code#

For this reason, you should not overuse any function that creates a dialog box (or modal window).вЂќ вЂњDialog boxes are modal windowsвЂЉ-вЂЉthey prevent the user from accessing the rest of the programвЂ™s interface until the dialog box is closed. The scary thing about these dialogs, as can be found in the alert documentation, is: Each of these open up a dialog box at the top of the browsing context, regardless of whether it comes from the top-level window or not. JavaScript has three different functions that trigger a popupвЂЉ-вЂЉalert, prompt, and confirm. Should it be able to do this? That question brings us to our first area of concernвЂЉ-вЂЉpop-ups and dialog boxes. If you have alerts in your JS files like I do, you should have seen that each individual file triggers an alert at the top level of the browser. Refreshing the host page, you should now see two iframes, each with the content of our individual HTML files. This will become important in the cookies section below. Please note that we use localhost for the hosted-client and 127.0.0.1 for the other. We can do this using nodeвЂ™s http library to listen to and serve from two different ports.

#Html iframe code#

To simulate executing code from a different origin, we are going to set up two node serversвЂЉ-вЂЉone which weвЂ™ll call the host and second which we will call the client. Step 1: Setting up the servers for our demo application

Applying the sandbox attribute to the iframe and exploring the various options for the sandbox.

Embedding the content of our client page in an iframe on the host page and investigating what the client iframe is and is not allowed to do.

Setting up two node servers to simulate two different origins.

With all of that in mind, the guided walkthrough will consist of the following parts:

What we should end up with is a sandboxed environment in which we can execute any arbitrary JavaScript and still sleep well at night, knowing our host application will be safe from harm. In this post, weвЂ™ll demonstrate setting up a demo application from the ground up that will simulate running JavaScript coming from a different origin. The goal of this tutorial is to walk through the various security risks associated with running third-party JavaScript on your page and explain how sandboxed iframes can alleviate those issues by restricting the permissions it is allowed to run with. We all know about the iframe element in HTML, but how much do we really know about how it works? What are the security concerns associated with running code inside of an iframe and, furthermore, how can the HTML5 sandbox attribute on the frame alleviate these concerns? Whether itвЂ™s dropping a widget onto your web page or including custom content from a client in your cloud application, itвЂ™s something that many developers have encountered in their career. Understanding iFrame sandboxes and iFrame securityД®mbedding third-party JavaScript in web applications is a tale as old as time.