git.r.bdr.sh - rbdr/forum/blob - app/stores/forums.js

   1 import { readable } from 'svelte/store';
   2 import { onMessage } from '../socket_coordinator';
   3
   4 const internals = {
   5
   6   // Constants
   7
   8   kChangeFeedEventName: 'changefeed:forums',
   9
  10   // The exported data structure
  11
  12   forums: [],
  13
  14   // Handles messages from the event
  15
  16   handleChangeFeed(data) {
  17
  18     // No old value == add
  19     if (!data.old_val) {
  20       return internals.forums.push(data.new_val);
  21     }
  22
  23     // We have an old value, let's find it.
  24     const index = internals.forums.findIndex((element) => element.id === data.old_val.id);
  25
  26     if (index > -1) {
  27       if (data.new_val) {
  28         return internals.forums.splice(index, 1, data.new_val || undefined);
  29       }
  30
  31       return internals.forums.splice(index, 1);
  32     }
  33   }
  34 };
  35
  36 export const forums = readable(internals.forums, (set) => {
  37
  38   onMessage((message) => {
  39
  40     if (message.name === internals.kChangeFeedEventName) {
  41       internals.handleChangeFeed(message.data);
  42       set(internals.forums);
  43     }
  44   });
  45 });