JSON RPC

Kakoune is able to talk to the outside world using a protocol called JSON-RPC

There's already a document describing what kind of information can transit during this discussion. I encourage you to read it first.

This wiki page will attempt to illustrate how you can use this kakoune feature.

Output: draw, draw_status

Let's start by creating a brand new normal kakoune client. Open a terminal and run:

kak -s yolo

Here the -s flag indicates that we want to create a brand new yolo session.

Open a second terminal, this time we create a kakoune client that does not display a nice ncurses GUI on the screen but print raw JSON output.

kak -c yolo -ui json

Since we decided to connect to the same yolo session. Everything you do in the first client will be mirrored in the second one. This way you can easily discover what's going on.

Example of JSON output when the second client is launched :

{ "jsonrpc": "2.0", "method": "draw", "params": [[[{ "face": { "fg": "#303030", "bg": "#d7d7d7", "attributes": [] }, "contents": "\u000a" }, { "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": "" }]], { "fg": "#d7d7d7", "bg": "#303030", "attributes": [] }, { "fg": "#afd787", "bg": "#303030", "attributes": [] }] }
{ "jsonrpc": "2.0", "method": "menu_hide", "params": [] }
{ "jsonrpc": "2.0", "method": "info_hide", "params": [] }
{ "jsonrpc": "2.0", "method": "draw_status", "params": [[], [{ "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": "*scratch* 1:1 " }, { "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": " " }, { "face": { "fg": "#444444", "bg": "#d7d7d7", "attributes": [] }, "contents": "1 sel" }, { "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": " - unnamed1@[yolo]" }], { "fg": "#d7d7d7", "bg": "#444444", "attributes": [] }] }
{ "jsonrpc": "2.0", "method": "refresh", "params": [true] }

After typing iHello<esc> in the first client, here's what the output :

{ "jsonrpc": "2.0", "method": "draw", "params": [[[{ "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": "Hello" }, { "face": { "fg": "#303030", "bg": "#d7d7d7", "attributes": [] }, "contents": "\u000a" }, { "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": "" }]], { "fg": "#d7d7d7", "bg": "#303030", "attributes": [] }, { "fg": "#afd787", "bg": "#303030", "attributes": [] }] }
{ "jsonrpc": "2.0", "method": "draw_status", "params": [[], [{ "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": "*scratch* 1:6 " }, { "face": { "fg": "#d7d7d7", "bg": "#5f875f", "attributes": [] }, "contents": "[+]" }, { "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": " " }, { "face": { "fg": "#444444", "bg": "#d7d7d7", "attributes": [] }, "contents": "1 sel" }, { "face": { "fg": "default", "bg": "default", "attributes": [] }, "contents": " - unnamed1@[yolo]" }], { "fg": "#d7d7d7", "bg": "#444444", "attributes": [] }] }
{ "jsonrpc": "2.0", "method": "refresh", "params": [true] }

We can see the Hello contents in the draw method.