#Frontend

This post is intended to guide you through the new JSON capabilities that we introduced in Caché 2016.1. JSON has emerged to a serialization format used in many places. The web started it, but nowadays it is utilized everywhere. We've got plenty to cover, so let's get started.

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.

• WebSocket protocol

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.

In this article I'll cover testing and debugging Caché web applications (mainly REST) with external tools. Second part covers Caché tools.

You wrote server-side code and want to test it from a client or already have a web application and it doesn't work. Here comes debugging. In this article I'll go from the easiest to use tools (browser) to the most comprehensive (packet analyzer), but first let's talk a little about most common errors and how they can be resolved.

ˮ This is one of my articles which was never published in English. Let's fix it!

In this article, I would show how you can upload and download files from InterSystems products via http.

The questions about working with files over http arise fairly often on community and I'm usually linking to my FileServer project which demonstrates file upload/download but I'd like to talk a bit more on how we can serve and receive files from InterSystems products.

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.

There are several options how to deliver user interface(UI) for DeepSee BI solutions. The most common approaches are:

• use native DeepSee Dashboards, get web UI in Zen and deliver it in your web apps.
• use DeepSee REST API, get and build your own UI widgets and dashboards.

The 1st approach is good because of the possibility to build BI dashboards without coding relatively fast, but you are limited with preset widgets library which is expandable but with a lot of development efforts.

The 2nd provides you the way to use any comprehensive js framework (D3, Highcharts, etc) to visualize your DeepSee data, but you need to code widgets and dashboards on your own.

Today I want to tell you about yet another approach which combines both listed above and provides Angular based web UI for DeepSee Dashboards - DeepSee Web library.

Question

I am configuring IIS to work with the CSP Gateway but I'm running into this error:

"The Module DLL 'C:\Inetpub\CSPGateway\CSPms.dll' could not be loaded due to a configuration problem. The current configuration only supports loading images built for a x86 processor architecture."

Answer

How to parse a URL in Caché:

Let's pretend you are working on a project where you may be retrieving a URL for some purpose and you have the need to be easily able to parse apart that URL to get the various components that make up the URL.

Here's how to do that:

In the first article I started discussing RESTForms - REST API for your persistent classes. We talked about basic features, now, I'd like to discuss advanced features - mainly queries capabilites:

• Basic queries
• Query arguments
• Custom queries

Queries

Queries allow getting slices of data, based on arbitrary criteria. There are two query types in RESTForms:

• Basic queries work for all RESTForms classes once defined and they differ only by the field list
• Custom queries work only for the classes in which they are specified and available, but the developer has full access to query text

Index to Articles

Published 2018-05-11 Last edit -

Hi All

I this article I detail some strategic issues that a new development UI will need to address - these are the ones that I can think of now - others may come to light during this journey.

See the webinar by Eduard Lebedyuk here from the last Global Summit describing modern web development and Caché

And, as always, if I have missed something please comment....

Sometimes you can face the situation when you did update the web app on Caché server but you cannot get the newest version of the app in a browser.

Here are couple recipes which help me to solve it. From simplest to more sophisticated and not obvious.

1. Refresh page in a browser

In Chrome it is Ctrl+R or 'Refresh' button. Obvious, but helpful.

2. Hard reset in a browser

If you are in Chrome, open Developer tools

As web application gets more complex, more technologies are involved into the application development. Once it gets deployed in large scale the configuration gets more complex too. For sure one of the most difficult part of the story is the security. In a complex solution when independent servers are feeding single web pages with contents, it is indeed challenging to keep the integrity of such system. HTML5 introduced a (weak) security constraint, the Cross Origin Resource Sharing (CORS). This article tells how to enable CORS for CSP/ ZEN applications.