Disable auto delete of local storage

programming web dev
1

I like to create PWAs with local storage.

I don’t want the browser to auto delete the local storage.
Even indexedDB gets deleted after seven days of inactivity!

I wished PWA got the same treatment as local apps on a mobile device!

Any tips?

2

Hi Wayne! Store the data in the cloud AND local storage. If the local storage gets cleared, fetch the latest copy from the cloud. Would that work?

Cheers,
Kirupa :unibrow:

3

Hey mate,

From what I can tell there is some form of persistence with this this API.

I’m not 100% on this because I use the file system for my personal apps and don’t really care about persisting data on web pages with SW’s.

Here’s my little snippet for a basic File System API (works in chrome and edge).

Have a play with that and get a feel for it… :slightly_smiling_face:

export
    class FS {
    static #currentFolder
    static #currentFile

    static async openFolder() {
        try { FS.currentFolder = await window.showDirectoryPicker({ mode: "readwrite", startIn: "desktop" }) }
        catch (err) { return "cancelled" }

    }

    static async openFile(fileName) {
        if (FS.#currentFolder == null) await FS.openFolder()
        try {
            let fileHandle = await FS.#currentFolder.getFileHandle(fileName)
            let blob = await fileHandle.getFile()
            let text = await blob.text()
            return text
        }
        catch { return "not found" }
    }

    static async createFile(newName) {
        if (FS.#currentFolder == null) await FS.openFolder()
        try {
            for await (const [name, handle] of FS.#currentFolder.entries()) {

                if (name == newName) { return alert('file name in use') }
            }
            let newFile = await FS.#currentFolder.getFileHandle(newName, { create: true });
            return newFile
        }
        catch { return "failed" }
    }

    static async saveFile(fileName, data) {
        let fileHandle;
        try {
            for await (const [name, handle] of FS.#currentFolder.entries()) { if (name == fileName) { fileHandle = handle; break } }
            if (!fileHandle) return
            let writableStream = await fileHandle.createWritable();
            await writableStream.write(data);
            await writableStream.close();
        }
        catch { "failed" }
    }

    static async deleteFile(fileName) {
        try { await FS.#currentFolder.removeEntry(fileName) }
        catch { "failed" }
    }
}
4

I can’t store to the cloud because I want to avoid gdpr rules :sweat_smile:

I can’t find what StorageManager is. Is it storing files on device?

6

From what I can tell navigator.storage returns a read only object called StorageManager

This Object allows you to:

  • estimate() : “query” how much data your origin has been allowed on the device for localStorage, caches, indexedDB sessionStorage ect

  • persist() : request permission to persist data from your origin

  • persisted(): boolean if your origins data is persisted

  • getDirectory() : access the file system directory for various operations

The code below should persist your data unless the user clears their history/ storage ect

if (navigator.storage && navigator.storage.persist) {
  navigator.storage.persist().then((persistent) => {
    if (persistent) {
      console.log("Storage will not be cleared except by explicit user action");
    } else {
      console.log("Storage may be cleared by the UA under storage pressure.");
    }
  });
}

TBH I haven’t tested it because I just use the file system…

1 Like
7

Thank you! I will give it a try

9

It’s very sad how pwa never take off as I wanted. I have to write a native app to be able to store simple data for offline or use the cloud which violates GDPR

1 Like
10

With Apple backtracking a bit with PWAs in the EU, the PWA shine continues to wear off.

11

Can you by any chance speed me up to join project idx? I’m on a waiting list :pray:

12

PM me the email address you used to sign-up and I’ll see what I can do.

13

There might be another option to use a PWA with IOS file sytem.

This guy built a doodle app and published to APP store with a single html file using capacitor JS…

Capacitor also has a file system API…