1
/*
2
 *  This file is part of CoCalc: Copyright © 2020 Sagemath, Inc.
3
 *  License: MS-RSL – see LICENSE.md for details
4
 */
5

6
import { AppRedux } from "../app-framework";
7
import { bind_methods } from "@cocalc/util/misc";
8
import { webapp_client } from "../webapp-client";
9

10
export type TableConstructor<T extends Table> = new (name, redux) => T;
11

12
export abstract class Table {
13
  public name: string;
14
  public _table: any;
15
  protected redux: AppRedux;
16

17
  // override in derived class to pass in options to the query -- these only impact initial query, not changefeed!
18
  options(): any[] {
19
    return [];
20
  }
21

22
  abstract query(): void;
23

24
  protected abstract _change(table: any, keys: string[]): void;
25

26
  protected no_changefeed(): boolean {
27
    return false;
28
  }
29

30
  constructor(name, redux) {
31
    bind_methods(this);
32
    this.name = name;
33
    this.redux = redux;
34
    if (this.no_changefeed()) {
35
      // Create the table but with no changefeed.
36
      this._table = webapp_client.sync_client.synctable_no_changefeed(
37
        this.query(),
38
        this.options(),
39
      );
40
    } else {
41
      // Set up a changefeed
42
      this._table = webapp_client.sync_client.sync_table(
43
        this.query(),
44
        this.options(),
45
      );
46
    }
47

48
    this._table.on("error", (error) => {
49
      console.warn(`Synctable error (table='${name}'):`, error);
50
    });
51

52
    if (this._change != null) {
53
      // Call the _change method whenever there is a change.
54
      this._table.on("change", (keys) => {
55
        this._change(this._table, keys);
56
      });
57
    }
58
  }
59

60
  close = () => {
61
    this._table.close();
62
  };
63

64
  set = async (
65
    changes: object,
66
    merge?: "deep" | "shallow" | "none", // The actual default is "deep" (see @cocalc/sync/table/synctable.ts)
67
    cb?: (error?: string) => void,
68
  ): Promise<void> => {
69
    if (cb == null) {
70
      // No callback, so let async/await report errors.
71
      // Do not let the error silently hide (like using the code below did)!!
72
      // We were missing  lot of bugs because of this...
73
      this._table.set(changes, merge);
74
      await this._table.save();
75
      return;
76
    }
77

78
    // callback is defined still.
79
    let e: undefined | string = undefined;
80
    try {
81
      this._table.set(changes, merge);
82
      await this._table.save();
83
    } catch (err) {
84
      e = err.toString();
85
    }
86
    cb(e);
87
  };
88
}
89

90