c#

HTTPS POST and PlantUML, your best friend.

Juan Tenorio

• 2 min read
HTTPS POST and PlantUML, your best friend.
Photo by Kevin Bhagat / Unsplash

Hello!!!

This will be a short post

Currently I am working on automating the creation of PlantUML diagrams and embed them into Word documents and Excel Spreadsheets (Yes that is a thing)

But instead of copying the image from the PlantUML server, I will be generating the diagram dynamically and obtain the image as a stream and save into the document or anything really.

Enter the POST verb for the PlantUML server.

If you remember, we created a server from this post

https://darthseldon.net/plantuml-and-nginx-your-own-uml-designer/

We will be using the same server for our purposes.

I will be using Postman, but you can use CURL or any http client you want to use.

Add a post request to your server

As an example, I will use http://localhost:8080/png

You will notice the png at the end, this is the endpoint that will return the response from the server in that format.

Now for the content of the request, we will be using the sample for a sequence diagram

@startuml

'standard libraries
!include <C4/C4_Container>
!include <azure/AzureCommon>
!include <azure/Databases/AzureSqlServer>
!include <tupadr3/common>
!include <office/Servers/application_server>
!include <office/Concepts/application_generic>

'header
title Stylish Sequence Diagram

'actors and participants
actor "Client" as client
participant "<$application_server>\nIdentity Server Provider" as idp
participant "<$application_generic>\nAPI" as api
participant "<$AzureSqlServer>\nProducts Database" as database

'interactions
autonumber "<b>[000]"

  group Authentication
    client -> idp: Authentication Request
    activate idp
      idp --> client: Authentication Response
    deactivate idp
  end

  group Obtain Products
    client -> api: Get Products
    activate api
      api -> database : Query Products
      activate database
        database --> api : Products
      deactivate database
      api --> client : JSON Products
    deactivate api
  end

'footer
footer v1.0

@enduml

And TA-DA

The result is an image/png

You can stream it, save it, resend it, etc. The possibilities are quite a few

How about other formats? Well, if you change the png for svg, it will create it as vector graphics

Other formats are:

  • png
  • svg
  • txt (ascii)
  • pdf

Pretty cool. Like I said short post.

Happy coding!!!