Towards Rye's minimal web-application library

It's a grading season in our COVID-19 home-schooling experiment. I will help my kids learn so I reopened some javascript tool I jotted together a year or two ago to quickly write down notes, trees and graphs when we learned history. It's just a bunch of JavaScript and I decided that I should add a simple backend to it, so I can save notes like a normal person. Then I might have motivation to improve on it and make it more generally usefull.

This was an excuse to start writing a very minimal web-application server in Rye. It will follow the similar system that my Rebol apps use since pre-2009. The backend is a STRPC API. It stands for SoTinyRPC and is a really simple HTTP-based way of calling functions on the server. It's very easy to implement a client in any language, curl, or just a html form. It's very easy to serve on a server. My production implementation features multiple return formats, clear validation errors, multiple method calls in one http call and also offers self documenting explore mode.

I added a lot of new basic and http related functions to Rye today. Like any, all, to-word, probe, mold (which are straight from Rebol), code?, check, to-json . I added an interesting function require which sort of un-nests the if-s. It's a go-ism, where flatter happy paths are desirable.

To the http module I added query?, form?, full-form?, set-content-type and write-header. All of these are generic methods and dispatch on server-response-writer or server-request.

There is still much to do, but many mechanisms are in place now. The requests are passed to the right resource (_r) and method (_m). Data is validated with the validation dialect, results of a webfn are converted to JSON and returned. Errors set the right http status and are returned as JSON also.

This example creates two resources, each with one demo method. Next I should add a session support and postgresql, so it will look more realistic. SQL dialect in conjunction with webfn should be nice too.

The "web framework" for this are just 5 functions below. Nothing special, except webfn which is a "function creating function". Something you probably can't see in most programming languages. It's like defining a your own def in Python. Rye is homoiconic but there is no code generation or macros needed for this.

This is the behavior we get. With correct id of 77 ...

... and an error with any other id. Notice the nested errors.

That's it for now. As I said, session management and posgresql functions are next.

Komentarji

Priljubljene objave iz tega spletnega dnevnika

Less variables, more flows example vs Python

In the last blogpost ( Less variables, more flows ) I wrote a quick practical script I needed. It was an uncommon combination of CGI, two GET requests with Cookies and a POST request with Authorization header. I really like practical random/dirty problems, rather than ideal - made up problems to test the language. To get a sense of comparison I rewrote the example 2 times while removing specific Rye features. But that comparison is meaningless to a person that doesn't know Rye or at least Rebol already. So I went on fiverr and made a request for a Python script with these requirements. I got a nicely written Python script that uses functions for each step. To be more comparable, I rewrote the Rye code to a similar structure. Below is the result ... For a next step, it would be interesting, to extract a little simpler example out and add error handling. With Rye-s specific failure handling, I think the difference would become even greater. You can find Rye on github .

Preberite več

Ryelang - controlled file serving example and comparison to Python

This is as anecdotal as it gets, but basic HTTP serving functions in Rye seem to be working quite OK. They do directly use the extremely solid Go 's HTTP functions, so that should be somewhat expected. I made a ryelang.org web-server with few lines of Rye code 3 months ago and the process was running ever since and served more than 30.000 pages. If not else, it seems there are no inherent memory leaks in Rye interpreter. Those would probably show up in a 3 month long running process? And now I got another simple project. I needed to make a HTTP API for some mobile app. API should accept a key, and return / download a binary file in response if the key is correct. Otherwise it should return a HTTP error. So I strapped in and created Rye code below. I think I only needed to add generic methods stat and size? , all other were already implemented, which is a good sign. Of course, we are in an age of ChatGPT, so I used it to generate the equivalent Python code. It used the ele...

Preberite več

Receiving emails with Go's smtpd and Rye

This goes a while back. At some project for user support, we needed to receive emails and save them to appropriate databases. The best option back in the day seemed project Lamson . And it worked well ever since. It was written in Python by then quite known programmer Zed Shaw. It worked like a Python based SMTP server, that called your handlers when emails arrived. It was sort of Ruby on Rails for email. We were using this ever since. Now our system needs to be improved, there are still some emails or attachments that don't get parsed correctly. That isn't the problem of Lamson, but of our code that parses the emails. But Lamson development has been passive for more than 10 years. And I am already moving smaller utilities to Rye. Rye uses Go, and Go has this nice library smtpd , which seems like made for this task. I integrated it and parsemail into Rye and tested it in the Rye console first. Interesting function here is enter-console , that can put you into Rye console any...

Preberite več

ryelang

Preišči ta spletni dnevnik