What is the permissions to set for FS plugin?

[bouteillerAlan]

Hello, I want to write / read a file in app local data and another in app config.

So for that I have set up a very simple service (code is still very wip):

import {writeFile, BaseDirectory, readFile} from '@tauri-apps/plugin-fs';

/**
 * write the data in the file
 * /!\ if the file doesn't exist the file is created
 * /!\ if  the file exist the file is overwritten
 * @param data string the data you want to write in the file
 * @param file 'config.json' | 'history.json' name of the file with extension
 */
export async function writeContentInFile(data: string, file: 'config.txt' | 'history.txt'): Promise<boolean> {
  const encoder: TextEncoder = new TextEncoder();
  const dataUint: Uint8Array = encoder.encode(data);

  try {
    if (file === 'config.txt') {
      await writeFile(file, dataUint, {baseDir: BaseDirectory.AppConfig});
    } else {
      await writeFile(file, dataUint, {baseDir: BaseDirectory.AppLocalData});
    }
    return true;
  } catch (e) {
    console.log(e);
    return false;
  }
}

/**
 * read the content of file and return it
 * @param file 'config.json' | 'history.json' name of the file with extension
 * @return string
 */
export async function getContentFromFile(file: 'config.txt' | 'history.txt'): Promise<string> {
  const decoder: TextDecoder = new TextDecoder();

  try {
    if (file === 'config.txt') {
      const data: Uint8Array = await readFile(file, {baseDir: BaseDirectory.AppConfig});
      return decoder.decode(data);
    } else {
      const data: Uint8Array = await readFile(file, {baseDir: BaseDirectory.AppLocalData});
      return decoder.decode(data);
    }
  } catch (e) {
    console.log(e);
    return '';
  }
}

Now, according to the documentation, the writeFile() function could create a new file if the file doesn't exist.

But when I use my function, I get (from the console.log) the following message: failed to open file at path: /home/a2n/.config/com.postier.app/config.txt with error: No such file or directory (os error 2).

So I'm telling myself that my permission is not set up correctly (see below). What permission do we have to add to get the permission to read / write in local data, for example?

A clear permission config example in each subsection of this section could be very useful, since they're affect the use of each function.

{
  "$schema": "../gen/schemas/desktop-schema.json",
  "identifier": "default",
  "description": "Capability for the main window",
  "windows": [
    "main"
  ],
  "permissions": [
    "core:default",
    "opener:default",
    {
      "identifier": "fs:allow-write",
      "allow": [
        {
          "path": "$APPLOCALDATA/*"
        },
        {
          "path": "$APPCONFIG/*"
        }
      ]
    },
    {
      "identifier": "fs:allow-exists",
      "allow": [
        {
          "path": "$APPLOCALDATA/*"
        },
        {
          "path": "$APPCONFIG/*"
        }
      ]
    },
    {
      "identifier": "fs:allow-create",
      "allow": [
        {
          "path": "$APPLOCALDATA/*"
        },
        {
          "path": "$APPCONFIG/*"
        }
      ]
    },
    {
      "identifier": "fs:allow-appconfig-read",
      "allow": [
        {
          "path": "$APPLOCALDATA/*"
        },
        {
          "path": "$APPCONFIG/*"
        }
      ]
    },
    {
      "identifier": "fs:allow-applocaldata-read",
      "allow": [
        {
          "path": "$APPLOCALDATA/*"
        },
        {
          "path": "$APPCONFIG/*"
        }
      ]
    },
    {
      "identifier": "fs:allow-applocaldata-write",
      "allow": [
        {
          "path": "$APPLOCALDATA/*"
        },
        {
          "path": "$APPCONFIG/*"
        }
      ]
    },
    {
      "identifier": "fs:allow-appconfig-write",
      "allow": [
        {
          "path": "$APPLOCALDATA/*"
        },
        {
          "path": "$APPCONFIG/*"
        }
      ]
    },
    {
      "identifier": "http:default",
      "allow": [
        {
          "url": "http://*"
        },
        {
          "url": "https://*"
        }
      ]
    },
    {
      "identifier": "http:allow-fetch-read-body",
      "allow": [
        {
          "url": "http://*"
        },
        {
          "url": "https://*"
        }
      ]
    }
  ]
}

[FabianLars]

It will create the file but not the directory and i assume it's the directory that's still missing here. So you'll also need mkdir and its permission should be $APPLOCALDATA (or config) without the /*

[bouteillerAlan]

So I have added this function (and the permission like you say), everything work, is this the right way to do it?

The function is called just before writeFile().

export async function createAppFolderIfNotExist() {
  const configExist = await exists('.', { baseDir: BaseDirectory.AppConfig });
  const localDataExist = await exists('.', { baseDir: BaseDirectory.AppLocalData });
  if (!configExist) await mkdir('', { baseDir: BaseDirectory.AppConfig });
  if (!localDataExist) await mkdir('', { baseDir: BaseDirectory.AppLocalData });
}

[FabianLars]

yep, that's good. technically the exists call isn't really needed, mkdir wouldn't delete and recreate or anything like that.

[bouteillerAlan]

ok thanks :)