
# Yet Another Remote Plugin Framework for Neovim

This is my attempt on writing a remote plugin framework without
`:UpdateRemotePlugins`.

## Requirements

- `has('python3')`
- For Vim 8:
  - [roxma/vim-hug-neovim-rpc](https://github.com/roxma/vim-hug-neovim-rpc)
  - `g:python3_host_prog` pointed to your python3 executable, or `echo
      exepath('python3')` is not empty.
  - [pynvim](https://github.com/neovim/pynvim) (`pip3
      install pynvim`)

## Installation

### With [Vim-Plug](https://github.com/junegunn/vim-plug), use:

```vim
    " Required for vim 8
    Plug 'roxma/vim-hug-neovim-rpc'
    " Install this plugin
    Plug 'roxma/nvim-yarp', { 'do': 'pip install -r requirements.txt' }
```

## Use case

- [shougo/deoplete.nvim](https://github.com/shougo/deoplete.nvim)
- [ncm2/ncm2](https://github.com/ncm2/ncm2) and most of its plugins

## Usage

pythonx/hello.py

```python
import vim, time
def greet():
    time.sleep(3)
    vim.command('echo "Hello world"')
```

plugin/hello.vim

```vim
" Create a python3 process running the hello module. The process is lazy load.
let s:hello = yarp#py3('hello')

com HelloSync call s:hello.request('greet')
com HelloAsync call s:hello.notify('greet')

" You could type :Hello greet
com -nargs=1 Hello call s:hello.request(<f-args>)
```

## Debugging

Add logging settigns to your vimrc. Log files will be generated with prefix
`/tmp/nvim_log`. An alternative is to export environment variables before
starting vim/nvim.

```vim
let $NVIM_PYTHON_LOG_FILE="/tmp/nvim_log"
let $NVIM_PYTHON_LOG_LEVEL="DEBUG"
```

## Options

`let s:yarp.on_load = function('your_handler')`

A handler that is called after your python module is loaded. It is not
considered ready for request or notification from vimscript during loading
stage. `s:yarp.request` and `s:yarp.notify` internally wait until `on_load`
before sending actual request and notification.

## Methods

`call s:yarp.reqeust({event}, [, {args}...])`

Similiar to `:help rpcrequest`. It sends a request to the rpc channel and
returns the result of your python method.

`call s:yarp.rpcnotify({event}, [, {args}...])`

Similiar to `:help rpcnotify`. It sends a notification to the rpc channel and
returns immediately.

`call s:yarp.error(msg)`

Print error message.

`call s:yarp.warn(msg)`

Print warning message.

## Example for existing neovim rplugin porting to Vim 8

More realistic examples could be found at
[nvim-typescript#84](https://github.com/mhartington/nvim-typescript/pull/84),
[deoplete#553](https://github.com/Shougo/deoplete.nvim/pull/553),
[callmekohei/quickdebug](https://github.com/callmekohei/quickdebug).

Now let's consider the following simple rplugin.

After `UpdateRemotePlugins` and restarting neovim, you get `foobar` by `:echo
Bar()`.

```python
# rplugin/python3/foo.py
import pynvim

@pynvim.plugin
class Foo(object):

    def __init__(self, vim):
        self._vim = vim

    @pynvim.function("Bar", sync=True)
    def bar(self, args):
        return 'hello' + str(args)
```

For working on Vim 8, you need to add these two files:


```vim
" plugin/foo.vim
if has('nvim')
    finish
endif

let s:foo = yarp#py3('foo_wrap')

func! Bar(v)
    return s:foo.call('bar',a:v)
endfunc
```


```python
# pythonx/foo_wrap.py
from foo import Foo as _Foo
import vim

_obj = _Foo(vim)


def bar(*args):
    return _obj.bar(args)
```

How to use
```
$ vim

: echo bar('world')

hello('world',)
```
