feat(fs): access security scoped resources on iOS (#3185)

Co-authored-by: FabianLars <30730186+FabianLars@users.noreply.github.com>

plugins/fs/src/ios.rs

@@ -0,0 +1,137 @@
+// Copyright 2019-2023 Tauri Programme within The Commons Conservancy
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-License-Identifier: MIT
+
+use serde::de::DeserializeOwned;
+use tauri::{plugin::PluginApi, AppHandle, Runtime};
+
+use crate::{FilePath, OpenOptions};
+
+pub struct Fs<R: Runtime> {
+    _phantom: std::marker::PhantomData<fn() -> R>,
+}
+
+pub fn init<R: Runtime, C: DeserializeOwned>(
+    _app: &AppHandle<R>,
+    _api: PluginApi<R, C>,
+) -> crate::Result<Fs<R>> {
+    Ok(Fs {
+        _phantom: std::marker::PhantomData,
+    })
+}
+
+impl<R: Runtime> Fs<R> {
+    /// Open a file.
+    ///
+    /// # Platform-specific
+    ///
+    /// - **iOS**: This method will automatically start accessing a security-scoped resource if the path is a file URL.
+    ///   You must call [`Self::stop_accessing_security_scoped_resource`] when you're done accessing the file.
+    pub fn open<P: Into<FilePath>>(
+        &self,
+        path: P,
+        opts: OpenOptions,
+    ) -> std::io::Result<std::fs::File> {
+        use objc2_foundation::{NSString, NSURL};
+
+        match path.into() {
+            FilePath::Url(url) if url.scheme() == "file" => {
+                // Handle security-scoped URLs on iOS
+                let url_string = url.as_str();
+                let url_nsstring = NSString::from_str(url_string);
+
+                // Create NSURL from the URL string
+                // URLWithString may return None for invalid URLs, but file:// URLs should be valid
+                let ns_url = unsafe { NSURL::URLWithString(&url_nsstring) };
+                if let Some(ns_url) = ns_url {
+                    // Start accessing the security-scoped resource
+                    // This is required for files outside the app's sandbox (e.g., from file picker)
+                    // Note: We don't call stopAccessingSecurityScopedResource here because
+                    // the file handle needs to remain accessible while the File is in use.
+                    // The access will be automatically stopped when the app is backgrounded or terminated.
+                    unsafe {
+                        let success = ns_url.startAccessingSecurityScopedResource();
+                        if success {
+                            log::debug!(
+                                "Started accessing security-scoped resource for URL: {}",
+                                url_string
+                            );
+                        } else {
+                            log::warn!(
+                                "Failed to start accessing security-scoped resource for URL: {}",
+                                url_string
+                            );
+                        }
+                    }
+                } else {
+                    log::debug!("Failed to create NSURL from URL: {}, ignoring security-scoped resource access request", url_string);
+                }
+
+                // Convert URL to path and open the file
+                let path = url.to_file_path().map_err(|_| {
+                    std::io::Error::new(std::io::ErrorKind::InvalidInput, "invalid file URL")
+                })?;
+                std::fs::OpenOptions::from(opts).open(path)
+            }
+            FilePath::Url(_) => Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidInput,
+                "cannot use a non-file URL to load files on iOS",
+            )),
+            FilePath::Path(p) => {
+                // Regular path, no security-scoped resource handling needed
+                std::fs::OpenOptions::from(opts).open(p)
+            }
+        }
+    }
+
+    /// Stops accessing a security-scoped resource for the given file path or URL.
+    /// This should be called when you're done accessing a file that was opened
+    /// using a security-scoped URL (e.g., from a file picker).
+    ///
+    /// # Arguments
+    ///
+    /// * `path` - A file path or URL that was previously accessed via `startAccessingSecurityScopedResource`
+    ///
+    /// # Returns
+    ///
+    /// Returns `Ok(())` if successful, or an error if the path/URL is invalid or not a file URL.
+    pub fn stop_accessing_security_scoped_resource<P: Into<FilePath>>(
+        &self,
+        path: P,
+    ) -> crate::Result<()> {
+        use objc2_foundation::{NSString, NSURL};
+
+        let file_path = path.into();
+        let url_string = match file_path {
+            FilePath::Url(url) => {
+                if url.scheme() != "file" {
+                    return Err(crate::Error::InvalidPathUrl);
+                }
+                url.as_str().to_string()
+            }
+            FilePath::Path(p) => {
+                // Convert path to file URL
+                url::Url::from_file_path(&p)
+                    .map_err(|_| crate::Error::InvalidPathUrl)?
+                    .as_str()
+                    .to_string()
+            }
+        };
+
+        let url_nsstring = NSString::from_str(&url_string);
+        let ns_url = unsafe { NSURL::URLWithString(&url_nsstring) };
+        if let Some(ns_url) = ns_url {
+            // Stop accessing the security-scoped resource
+            unsafe {
+                ns_url.stopAccessingSecurityScopedResource();
+            }
+        } else {
+            return Err(crate::Error::Io(std::io::Error::new(
+                std::io::ErrorKind::InvalidInput,
+                "failed to create NSURL from URL",
+            )));
+        }
+
+        Ok(())
+    }
+}