gristlabs_grist-core/app/common/ActionRouter.ts

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import { Rpc } from "grain-rpc";
/**
* ActionRouter allows to choose what actions to send over rpc. Action are posted as message `{type:
* "docAction", action }` over rpc.
*/
export class ActionRouter {
private _subscribedTables: Set<string> = new Set();
constructor(private _rpc: Rpc) {}
/**
* Subscribe to send all actions related to a table. Keeps sending actions if table is renamed.
*/
public subscribeTable(tableId: string): Promise<void> {
this._subscribedTables.add(tableId);
return Promise.resolve();
}
/**
* Stop sending all message related to a table.
*/
public unsubscribeTable(tableId: string): Promise<void> {
this._subscribedTables.delete(tableId);
return Promise.resolve();
}
/**
* Process a action updates subscription set in case of table rename and table remove, and post
* action if it matches a subscriptions.
*/
public process(action: any[]): Promise<void> {
const tableId = action[1];
if (!this._subscribedTables.has(tableId)) {
return Promise.resolve();
}
switch (action[0]) {
case "RemoveTable":
this._subscribedTables.delete(tableId);
break;
case "RenameTable":
this._subscribedTables.delete(tableId);
this._subscribedTables.add(action[2]);
break;
}
return this._rpc.postMessage({type: "docAction", action});
}
}