element-web/src/SendHistoryManager.ts
Michael Telatynski 017d2d40fe Update CIDER local and session storage keys to unbrick downgrade compat
Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>
2020-10-08 09:51:31 +01:00

75 lines
2.5 KiB
TypeScript

//@flow
/*
Copyright 2017 Aviral Dasgupta
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
import {clamp} from "lodash";
import {MatrixEvent} from "matrix-js-sdk/src/models/event";
import {SerializedPart} from "./editor/parts";
import EditorModel from "./editor/model";
interface IHistoryItem {
parts: SerializedPart[];
replyEventId?: string;
}
export default class SendHistoryManager {
history: Array<IHistoryItem> = [];
prefix: string;
lastIndex = 0; // used for indexing the storage
currentIndex = 0; // used for indexing the loaded validated history Array
constructor(roomId: string, prefix: string) {
this.prefix = prefix + roomId;
// TODO: Performance issues?
let index = 0;
let itemJSON;
while (itemJSON = sessionStorage.getItem(`${this.prefix}[${index}]`)) {
try {
this.history.push(JSON.parse(itemJSON));
} catch (e) {
console.warn("Throwing away unserialisable history", e);
break;
}
++index;
}
this.lastIndex = this.history.length - 1;
// reset currentIndex to account for any unserialisable history
this.currentIndex = this.lastIndex + 1;
}
static createItem(model: EditorModel, replyEvent?: MatrixEvent): IHistoryItem {
return {
parts: model.serializeParts(),
replyEventId: replyEvent ? replyEvent.getId() : undefined,
};
}
save(editorModel: EditorModel, replyEvent?: MatrixEvent) {
const item = SendHistoryManager.createItem(editorModel, replyEvent);
this.history.push(item);
this.currentIndex = this.history.length;
this.lastIndex += 1;
sessionStorage.setItem(`${this.prefix}[${this.lastIndex}]`, JSON.stringify(item));
}
getItem(offset: number): IHistoryItem {
this.currentIndex = clamp(this.currentIndex + offset, 0, this.history.length - 1);
return this.history[this.currentIndex];
}
}