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

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1 6 1,993
Article
Istvan Hahn · Sep 21, 2016 7m read
REST in Pieces

A beginners guide to develop Ensemble RESTful web services.

Background

Before you start reading this short introduction please go through the on-line documentation of Ensemble with special attention to chapter “Creating REST services and clients with Ensemble”.

The approach in the documentation is undisputable the fastest and easiest way to create RESTful services. As a beginner I went through the documentation and I had several questions. This short article is listing those questions plus my humble answers.

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Question
George Hodder · Jul 17, 2017
Connecting to a web service

Hi,

I am new to coding web services and trying to connect to an API that returns its format in xml or json.

I have a class as follows.. when I run I get back a 6059 in my status - Unable to open TCP/IP socket to server

Can someone help me identify what I am missing?  Thanks

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In this article, I would like to talk about the spec-first approach to REST API development.

While traditional code-first REST API development goes like this:

  • Writing code
  • REST-enabling it
  • Documenting it (as a REST API)

Spec-first follows the same steps but reverse. We start with a spec, also doubling as documentation, generate a boilerplate REST app from that and finally write some business logic.

This is advantageous because:

  • You always have relevant and useful documentation for external or frontend developers who want to use your REST API
  • Specification created in OAS (Swagger) can be imported into a variety of tools allowing editing, client generation, API Management, Unit Testing and automation or simplification of many other tasks
  • Improved API architecture.  In code-first approach, API is developed method by method so a developer can easily lose track of the overall API  architecture, however with the spec-first developer is forced to interact with an API from the position if API consumer which usually helps with designing cleaner API architecture
  • Faster development - as all boilerplate code is automatically generated you won't have to write it, all that's left is developing business logic.
  • Faster feedback loops - consumers can get a view of the API immediately and they can easier offer suggestions simply by modifying the spec

Let's develop our API in a spec-first approach!

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404 Not Found

{
"error": {
 "errors": [
  {
   "domain": "global",
   "reason": "notFound",
   "message": "Not Found"
  }
 ],
 "code": 404,
 "message": "Not Found"
 }
}

I want to do something like the above sample from a Google Storage JSON API. I have a call to Write obj.%ToJSON() followed by return ..ReportHttpStatusCode(..#HTTP404NOTFOUND) however the HTTP Status code is always 200.  If I remove the Write obj.%ToJSON() statement it returns a 404 status with no body. How do I return both?

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0 1 1,755
Question
Raouf Besbes · Jan 12, 2018
HTTP Response parsing error

Hello

I'm in the process of creating a TestClass which simulate a HTTP POST call to REST-based web
services and while I am having success, I'm struggling on how to parse out the results to a JSON
format

Here is down the code part which concerns parsing the HttpResponse.Data variable into JSON :

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Hi Developers!

Want to participate again in the competition of creating open-source solutions using InterSystems IRIS Data Platform? 

Then we're pleased to announce the second InterSystems IRIS Online Programming Contest!

And the topic for this contest is InterSystems IRIS with REST API.

The contest will again last three weeks: April 13-May 3, 2020

Also, please join the InterSystems Contests Discord Channel to chat about contest and technology.

 

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What if you could serialize/deserialize objects in whatever format: JSON, XML, CSV,...; attending different criteria: export/import some properties and not others, transform values in this or that way before exporting/importing,...; and all of this without having to change the class definition? Wouldn't that be great??

Well, perhaps it's a goal too ambitious to reach 100% but, exploring this idea, I've developed a bunch of classes that I thought it was good to share. If you want to test, change, modify or improve the code, or just take a look at it, you can do it here. There you'll find a more detailed explanation (see Readme.md)

Be aware, this is a proof of concept for myself done in spare times, sure it's not robust enough or it can be done much better... but, I was just playing...ok, I could just wait to the new JSON Adaptor (coming soon!) that sure is going to resolve much more scenarios in a cleaner way, but... meanwhile... :-) ...

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4 4 1,593
Question
Ricky Beca · Jul 31, 2017
Posting to a REST service

Hello,

 

I come from a programming background, but haven't touched ObjectScript before my current job, so please forgive my ignorance.

 

Within an Ensemble system, I need to post some information to a RESTful web service. I'm just trying to figure out how to create a method which takes a simple message and posts this off to a RESTful web service?

 

Thanks in advance for any help.

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0 3 1,554

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.

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3 2 1,547

I am happy to announce that InterSystems API Manager is now generally available. InterSystems API Manager (IAM) is a new feature of the InterSystems IRIS Data Platform™, enabling you to monitor, control and govern traffic to and from web-based APIs within your IT infrastructure.

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1 7 1,500

I cant find any description on how to read custom http request headers in a REST service.

On some occations i want to read http headers passed along when customers uses our REST API or headers added by the CND provider. Does anyone know how to read these http headers?

For example:
cloudflair.com sends a vistors country information along to the server using a customer http header called "CF-IPCountry". We would like to read this information and use it for statistics.

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Hello.

The idea of this post is to introduce Frontier: An abstraction layer that allows Rapid REST development.

REQUIREMENTS:

Why?

Have you ever found yourself dealing with repetitive tasks like mounting objects, serializing them and eventually handling multiple errors for multiple cases? Frontier can boost your development by making you focus on what really matters: your application.
 

Frontier is made to stop you from WRITE'ing by instead forcing your methods to return values.
It's designed to make you code clean, and you'll see the why pretty soon.

This is the Part 1, where you'll learn he basics about how to work with Frontier. That means at the end of this part you should be capable of 

creating GET requests without difficulties. Since this also serves as a way to introduce the framework, I'll be calling this part: Core concepts.

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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.

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Article
Istvan Hahn · Oct 6, 2016 4m read
RESTful Exception Handling

A beginner’s guide to Exception Handling in RESTful web services. The article gives an example how the various error conditions during processing a service request can be handled.

We expect our client – server communication working in a flawless operational condition, running error free software. But we are prepared to handle exceptions. Are we? So far in the examples of the previous sessions were not. We did not care about exceptions. The result? In any error incident it took ages to figure out what the problem is and more importantly how to fix it.

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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.

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Article
Nathan Ng · Sep 6, 2017 4m read
Polling an External REST API with Ensemble

Preface

Before we begin, I'd like to mention that I am by no means an Ensemble expert, so take this with a grain of salt and please feel free to offer any suggestions for improvement. That being said, I have enjoyed working with Ensemble and wanted to share the approach I took to poll an external REST API for patient data in the hopes that it might help others with a similar goal.

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