Start implementation of plain text export

src/utils/exportUtils/PlainTextExport.ts

@@ -0,0 +1,68 @@
+import streamSaver from "streamsaver";
+import Exporter from "./Exporter";
+import { Room } from "matrix-js-sdk/src/models/room";
+import { MatrixEvent } from "matrix-js-sdk/src/models/event";
+import { formatFullDateNoDay } from "../../DateUtils";
+import { _t } from "../../languageHandler";
+import * as ponyfill from "web-streams-polyfill/ponyfill"
+import { haveTileForEvent } from "../../components/views/rooms/EventTile";
+import { exportTypes } from "./exportUtils";
+import { exportOptions } from "./exportUtils";
+import { textForEvent } from "../../TextForEvent";
+
+export default class PlainTextExporter extends Exporter {
+    protected totalSize: number;
+    protected mediaOmitText: string;
+
+    constructor(room: Room, exportType: exportTypes, exportOptions: exportOptions) {
+        super(room, exportType, exportOptions);
+        this.totalSize = 0;
+        this.mediaOmitText = !this.exportOptions.attachmentsIncluded
+            ? _t("Media omitted")
+            : _t("Media omitted - file size limit exceeded");
+        window.addEventListener("beforeunload", this.onBeforeUnload)
+    }
+
+    protected onBeforeUnload = (e: BeforeUnloadEvent) => {
+        e.preventDefault();
+        return e.returnValue = "Are you sure you want to exit during this export?";
+    }
+
+    protected async createOutput(events: MatrixEvent[]) {
+        let content = "";
+        for (const event of events) {
+            if (!haveTileForEvent(event)) continue;
+            content += `${new Date(event.getTs()).toLocaleString()} - ${textForEvent(event)}\n`;
+        }
+        return content;
+    }
+
+    public async export() {
+        console.info("Starting export process...");
+        console.info("Fetching events...");
+        const fetchStart = performance.now();
+        const res = await this.getRequiredEvents();
+        const fetchEnd = performance.now();
+
+        console.log(`Fetched ${res.length} events in ${(fetchEnd - fetchStart)/1000} s`);
+        console.info("Creating Output...");
+
+        const text = await this.createOutput(res);
+
+        const filename = `matrix-export-${formatFullDateNoDay(new Date())}.txt`;
+
+        console.info("Writing to a file...");
+        //Support for firefox browser
+        streamSaver.WritableStream = ponyfill.WritableStream
+        //Create a writable stream to the directory
+        const fileStream = streamSaver.createWriteStream(filename);
+        const writer = fileStream.getWriter();
+        const data = new TextEncoder().encode(text);
+        await writer.write(data);
+        await writer.close();
+        const exportEnd = performance.now();
+        console.info(`Export Successful! Exported ${res.length} events in ${(exportEnd - fetchStart)/1000} seconds`);
+        window.removeEventListener("beforeunload", this.onBeforeUnload);
+    }
+}
+