meadbarrel / traad

An JSON+HTTP server for the rope Python refactoring library

Travis CI

Traad: Client-server Rope refactoring

Traad is a client-server approach to using the rope Python refactory library. It involves two basic components:

1. A HTTP server exposing the rope API via JSON, and
2. Client libraries (currently just emacs lisp) for talking to the server

The hope is that this approach will make it easier - at least in some cases - to use rope from various other tools.

Since rope is written in Python, any tool that wants to use rope needs to either embed Python, or it needs to find a way to communicate with a Python process running rope. The embedding approach is difficult if the target environment is not written in Python, and it also faces challenges when dealing with more than one Python version.

So traad aims to simplify communication with rope running in an independent process. HTTP communication and JSON data handling is well supported in many, many languages, so any environment that wants to use rope should be able to easily communicate with traad.

Most of the documentation for traad can be found on the wiki.

Emacs warning

There is a known problem with emacs-request that makes the traad emacs client misbehave when using Python3. You can fix this by patching request.el.

Quickstart for Emacs users

You can install the Emacs client for traad via package.el:

M-x package-install<RET>traad

Then you can use traad-install-server to install the Python server into a default location:

M-x traad-install-server

For more information on this process, see the wiki.

Setup

Install instructions can be found here.

Press

Here's a link to a presentation on traad/rope from EuroPython 2014.

Rationale

I (the author of traad) use emacs for most of my Python development, and I've often been jealous of the cool refactoring tools that my colleagues get with their fancy IDEs. Not jealous enough to actually switch, of course. I'm way to stubborn for that. But I was jealous enough that I investigated the options available for emacs.

One of the best options available is the rope Python refactoring library. Rope is very powerful and does all of the things I'd like. Unfortunately, I could never find a satisfactory way of integrating it into emacs. The pymacs-based approaches never quite worked for me, and in any case that approach struck me as somehow incorrect.

So, in the spirit of open-source development, I decided to try my own approach. I wanted a way to access rope functionality without having to contort either emacs or Python in unnatural ways. Thus the idea of using a client-server approach was born. It may strike others as odd or incorrect, but it works well for me.