Have you ever created an HTTP data request only to get hit by a red “access to HTML request has been blocked by cors policy” error?
When your site is on the same domain as the web service server, there’s no problem. However, this isn’t the case when performing a cross-origin request. Access is denied due to browser security preventing HTTP requests to another domain. The result? A CORS policy error.
To help you explicitly allow certain cross-origin requests on your server, 4D now supports the CORS protocol. Accessing data with cross-origin requests just became easier!
Do you need to load web pages, extract metadata, or generate pictures from the contents of pages on a headless server? If you answered “yes”, then you’re in luck because 4D v18 R3 makes it possible! Now you can create an offscreen web area with the WA Run offscreen area command.
Have you ever needed to use multiple web servers in order to, for example, split your web application code into several business units, or separate the administrator’s web server from the user’s or run an old part, not preemptive-ready yet, in a separate instance, allowing the main part to run preemptive?
If you’re nodding your head yes, then keep reading because 4D v18 R3 allows you to do so … with ease.
In a previous blog post, we showed you how to get started with the 4D REST server. We walked you through different CRUD operations using Postman and pointed you to the full REST documentation. In this blog post, We’ll explain how sessions work in 4D. This understanding will ensure that you’ll be able to build a session-based authentication system using the 4D REST server.
Want to retrieve data that isn’t available via REST or Web Services? What if it’s only available on a website? The data is easy enough for a human to read, but reading HTML data with a programming language isn’t so simple. Some developers try to use Position and Substring, others try Regex, but it’s unpleasant and time-consuming. A very different approach is to convert the HTML into an object and get the data via object notation. Table rows are handled as collections and are easy to loop through!
This blog post describes how to use this approach and provides some handy tips.
4D provides a powerful REST server, that enables direct access to data stored in your 4D databases. This makes it possible, for example, to build an API to use with a modern front end technology (e.g., Angular, React, etc). In this blog post, we’ll provide a first introduction to the 4D robust REST server. You’ll see how to configure it as well as test the create, retrieve, update, and delete (CRUD) operations using the API testing tool, Postman.
You asked for more information about web processes to better identify requests that might be slowing down or blocking your server. We heard you and in 4D v17 R5, we’ve added information about the URL used by web processes. This information can be retrieved two ways: via the 4D Server Administration Window or via the 4D language with the Get process activity command.
4D continues to deliver features to help you create your own applications to monitor your servers. From programmatically retrieving information about sessions, processes, and the application server, to getting information about the web server.
Having already provided you commands to read about statuses, 4D v17 R4 now gives you the ability to change statuses. You can now create your own administration interfaces as dialogs on the server, client, or even as HTML pages for web access. It’s up to you. These commands allow you to perform the same actions as the standard 4D administration interface. For example, you can send a message to your users to notify them of scheduled maintenance, or block new connections to the application server while you perform an operation on it.
Do you need to access your 4D data from a web page but don’t have a designer in your team? Are you uncomfortable designing the pages yourself because deep down you believe that it’s full of complicated and unwritten rules? Well, have you ever thought about Bootstrap?
In this blog post, we’ll look at how to take advantage of Bootstrap’s framework to design web pages in no time! We’ll also provide you with a database example to see how it can be combined with 4D transformation tags.
After introducing Perfect Forward Secrecy, the security level of 4D Web server has been increased again with the support of HTTP Strict transport Security (HSTS). Henceforth, 4D Web server is compliant with the very latest security protocols. Simply upgrade to 4D v17 and enable HSTS to get the A+ ranking (the highest level) from SSL Labs for your web sites!
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