New post

#JavaScript

8

JavaScript, often abbreviated as JS, is a high-level, interpreted programming language. It is a language which is also characterized as dynamic, weakly typed, prototype-based and multi-paradigm.

Learn more.

So, one day you're working away at WidgetsDirect, the leading supplier of widget and widget accessories, when your boss asks you to develop the new customer facing portal to allow the client base to access the next generation of Widgets..... and he wants you to use Angular 1.x to read into the department's Caché server.

There's only one problem: You've never used Angular, and don't know how to make it talk to Caché.

This guide is going to walk through the process of setting up a full Angular stack which communicates with a Caché backend using JSON over REST.

16 23
3 4.9K

Something that shot up the popularity stakes last week was this article on a very interesting initiative: RealWorld:

https://medium.com/@ericsimons/introducing-realworld-6016654d36b5

I decided it would be a good idea to use this as a way of creating an exemplar implementation of a RESTful back-end using QEWD against their published API (https://github.com/gothinkster/realworld/tree/master/api)

The results are here:

4 14
0 1.3K

Full-Stack JavaScript development allows you to create state-of-the-art applications with Caché. With any (web) app you build nowadays, one has to make a lot of architectural decisions and you want to make the right ones. With the Node.js connector available for Caché, you can create a very powerful server side application server, allowing you to use the latest JavaScript technology and frameworks client- and server-side.

With all these new technologies, the most important is to integrate them in the most efficient way and to create a very productive development experience. This article willl get you started step-by-step with Node.js technology.

9 13
1 3.1K

Developing a Full-Stack JavaScript web app with Caché requires you to bring together the right building blocks. In the previous part, we created a basic front-end React application. In the second part of this article series I will show how to choose the right back-end technology for your application. You will see Caché allows you to use many different approaches to link your front-end to your Caché server, depending on your application's needs. In this part we will set up a back-end with Node.js/QEWD and CSP/REST. In the next part we will enhance our basic web app and connect it to Caché using these technologies.

5 12
1 3.2K

Developing a Full-Stack JavaScript web app with Caché requires you to bring together the right building blocks. Previously, I outlined the basic steps to install and connect Node.js to Caché and make it's powerful multi-model database capabilites available for use with Node.js. You can use Caché as a NoSQL-, document- (with unique key-level access!), SQL- and object-database with Node.js. When developing JavaScript applications, you'll see how powerful this combination is and makes Caché a perfect fit for Node.js.

In the first part of this article series I will show how to get started with the React framework, one of the most popular frameworks currently taking over front-end development. In the next parts you'll learn how to connect a basic web app to a Caché back-end.

You'll see, it's very easy to get started with this technology - you can even compare the amount of basic knowledge you need to COS because you only need to know a few basic concepts to start!

9 8
2 4.9K
Article
· Mar 19, 2019 9m read
A Tutorial On WebSockets

Intro

Most server-client communication on the web is based on a request and response structure. The client sends a request to the server and the server responds to this request. The WebSocket protocol provides a two-way channel of communication between a server and client, allowing servers to send messages to clients without first receiving a request. For more information on the WebSocket protocol and its implementation in InterSystems IRIS, see the links below.

9 7
3 5.7K

Those of you who are following the FullStack competition here in the Developer Community will know that I submitted an entry named qewd-conduit. I wanted to summarise why I think it's something worth you taking a bit of time to check out.

qewd-conduit uses the Node.js-based QEWD framework alongside IRIS to implement the back-end REST APIs for something known as the RealWorld Conduit application:

https://github.com/gothinkster/realworld

Open Exchange app
5 6
1 528

Some time ago I got a WRC case transferred where a customer asks for the availability of a raw DEFLATE compression/decompression function built-in Caché.

When we talk about DEFLATE we need to talk about Zlib as well, since Zlib is the de-facto standard free compression/decompression library developed in the mid-90s.

Zlib works on particular DEFLATE compression/decompression algorithm and the idea of encapsulation within a wrapper (gzip, zlib, etc.).
https://en.wikipedia.org/wiki/Zlib

9 6
1 2.6K
Article
· Jul 31, 2019 2m read
Anti CSRF Methods

IRIS provides us with anti login CSRF attack mitigation, however this is not the same as a CSRF attack, as login attacks only occur on the login form. There are currently no built-in tools to mitigate CSRF attacks on api calls and other forms, so this is a step in mitigating these attacks.

See the following link from OWASP for the definition of a CSRF attack:

https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)

Open Exchange app
4 5
1 695
Article
· Sep 22 5m read
Database Management Tool

Introduction

Managing databases and performing CRUD operations are fundamental tasks for developers building data-driven applications. While many database management systems (DBMS) exist, they can be complex and cumbersome to interact with, especially when it comes to creating databases and tables, handling constraints, and performing real-time data operations through an API.

Open Exchange app
8 4
0 175

or "Didn't you say you would cover Persistent Objects in Part 5, Chris?"

Yes, that was the plan. This is a pretty important topic, so it get's its own Article

Up until now, we've display widget JSON that has been created by a basic loop. Clearly this isn't of much value. Now we have our stack connected together, and we can see that the data is flowing to the Welcome page, it's time to complete the stack and start feeding our service from "real" data.

2 4
0 1.5K

This is a quick note on what happens when, on your CSP page, you call a cache script which returns a %Boolean and store that value in a javascript variable.

When you call a script with language="cache" and returntype="%Boolean" from a javascript script, the return value is interpreted as a string, not as a boolean.

Here's an example:

A cache script that returns (in theory) a "false" value:

0 3
0 550
Article
· Jul 31, 2017 5m read
Introduction to QEWD Micro-Services

In my previous posting about the new support in QEWD for JSON Web Token (JWT) support, I mentioned that it was a key step in enabling Micro-Service support in QEWD. In this post I'll give some background to how they work and the thinking behind them.

If you haven't heard about Micro-Services and/or want to learn more, there's lots of information available if you do a Google Search. Here's a good starting point:

https://smartbear.com/learn/api-design/what-are-microservices/

3 3
0 722

We finished our last lesson with our Widgets Direct page iterating over a list of widgets, displaying an ID and a Name value. While we have been able to achieve this with only a small amount of coding, the page itself is not the most visually appealing place to be. The AngularJS framework is providing a powerful Model-View-Controller framework for our structure and logic, but it does not implement anything that will provide a nice UI experience.

6 3
0 1.7K

or "Things are going to break"

We left our application over the weekend, secure in the knowledge that it was returning data from our primary persistent class, User.Widget. However, Widgets Direct are the premier supplier of both Widgets AND Widget Accessories, so we should really start working on adding these Accessories to our application.

2 3
0 1.3K

There's a new and exciting enhancement to QEWD that has just been released - it's an additional layer of abstraction known as QEWD-Up. QEWD-Up hides away all the mechanics of QEWD itself, allowing you to focus on just your REST APIs and the code that implements them.

Additionally, and importantly, QEWD-Up simplifies the maintenance of your REST APIs, allowing you (and others) to quickly and easily understand their life-cycle and implementation.

3 3
4 816

Whats NLP Stands For?

NLP stands for Natural Language Processing which is a field of Artificial Intelligence with a lot of complexity and
techniques to in short words "understand what are you talking about".

And FHIR is...???

FHIR stands for Fast Healthcare Interoperability Resources and is a standard to data structures for healthcare. There are
some good articles here explainig better how FHIR interact with Intersystems IRIS.

Open Exchange app
4 2
0 731

or "Bonus Breakage"

In our last lesson, we added a relationship between 2 persistent classes. We are clearly going to need to start creating REST Services to expose CRUD operations for each of these classes, but before we do that, we should really finish defining our linkages. We added code to our Widget toJSON to spool off related Accessory data, so we should really do the reciprocal and allow Accessories to return all Widgets that are compatible.

3 2
1 1.2K
Article
· May 22, 2017 1m read
WebSockets v REST?

Most frameworks support either REST or WebSockets, and don't make it easy to switch between the two, and/or support both styles of application at the same time. WebSockets offer many advantages over REST, eg:

- most benchmarks show WebSocket messaging to be significantly faster than over HTTP

1 1
0 472

or "So you just got yelled at by your boss, for sending him an unformatted Hello World webpage"

Our previous lesson ended with us serving a Message value obtained from a Caché REST service to the client, using Angular as a runtime. While there is a lot of moving parts involved in this process, the page is not especially exciting at the moment. Before we can start adding new features, we should take a step back and review our tools.

12 1
1 2.5K