fix: isMyChild

Author: RohitKushvaha01

src/fileSystem/SAFDocumentFile.ts

@@ -36,50 +36,29 @@ export class SAFDocumentFile implements FileObject {
 		});
 	}
 
-	//if this fails then...
     async isMyChild(fileObject: FileObject): Promise<boolean> {
-        console.log(`[isMyChild] Checking if`, fileObject, `is a child of`, this);
-
         if (!(fileObject instanceof SAFDocumentFile)) {
             console.log(`[isMyChild] Not an SAFDocumentFile`);
             return false;
         }
 
-        const isDir = await this.isDirectory();
-        if (!isDir) {
-            console.log(`[isMyChild] This file is not a directory`);
-            return false;
-        }
-
-        let current: FileObject | null = fileObject;
-
-        while (current !== null) {
-            console.log(`[isMyChild] Checking parent of`, current);
-
-            const parent: FileObject | null = await current.getParentFile();
-            if (parent === null) {
-                console.log(`[isMyChild] Reached root without finding match`);
-                return false;
-            }
+        try {
+            console.log(`[isMyChild] Checking if ${fileObject.uri} is a child of ${this.uri}`);
+            const result = await this.execPlugin("isMyChild", [fileObject.uri]);
 
-            const parentUri = (await parent.toUri())?.replace(/\/+$/, "");
-            const thisUri = this.uri?.replace(/\/+$/, "");
+            // result will be 1 or 0 (from the native plugin)
+            const isChild = result === 1 || result === true;
 
-            console.log(`[isMyChild] parentUri=${parentUri}, thisUri=${thisUri}`);
-
-            if (parentUri === thisUri) {
-                console.log(`[isMyChild] Match found!`);
-                return true;
-            }
-
-            current = parent;
+            console.log(`[isMyChild] Result from native =`, isChild);
+            return isChild;
+        } catch (err) {
+            console.error(`[isMyChild] Error:`, err);
+            return false;
         }
-
-        console.log(`[isMyChild] No match found after traversal`);
-        return false;
     }
 
 
+
     async canRead(): Promise<boolean> {
 		const stat = await this.stat();
 		return !!stat.canRead;

src/plugins/file/src/android/documentFile.java

@@ -14,6 +14,8 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.charset.StandardCharsets;
+import android.provider.DocumentsContract;
+
 
 public class documentFile extends CordovaPlugin {
 
@@ -41,6 +43,7 @@ public boolean execute(String action, JSONArray args, CallbackContext callbackCo
                 case "canWrite": return handleCanWrite(args, callbackContext);
                 case "childByNameExists": return handleChildByNameExists(args, callbackContext);
                 case "getChildByName": return handleGetChildByName(args, callbackContext);
+                case "isMyChild": return handleIsMyChild(args, callbackContext);
                 case "toUri": return handleToUri(args, callbackContext);
                 default: return false;
             }
@@ -50,6 +53,55 @@ public boolean execute(String action, JSONArray args, CallbackContext callbackCo
         }
     }
 
+    private boolean handleIsMyChild(JSONArray args, CallbackContext cb) throws JSONException {
+        String parentUriStr = args.getString(0);
+        String childUriStr = args.getString(1);
+
+        try {
+            Uri parentUri = Uri.parse(parentUriStr);
+            Uri childUri = Uri.parse(childUriStr);
+
+            boolean result = false;
+
+            // SAF-safe check
+            if (DocumentsContract.isDocumentUri(getContext(), childUri)) {
+                try {
+                    result = DocumentsContract.isChildDocument(
+                        getContext().getContentResolver(),
+                        parentUri,
+                        childUri
+                    );
+                } catch (Exception e) {
+                    // If that fails, fallback to ID-based check
+                    result = isChildByDocIdFallback(parentUri, childUri);
+                }
+            } else {
+                // Non-SAF fallback: compare normalized paths
+                String p = parentUri.getPath();
+                String c = childUri.getPath();
+                if (p != null && c != null && c.startsWith(p)) {
+                    result = true;
+                }
+            }
+
+            cb.success(result ? 1 : 0);
+        } catch (Exception e) {
+            cb.error("Error: " + e.getMessage());
+        }
+        return true;
+    }
+
+    /**
+     * Fallback if DocumentsContract.isChildDocument() fails.
+     * Checks if the child’s document ID starts with parent’s document ID.
+     */
+    private boolean isChildByDocIdFallback(Uri parentUri, Uri childUri) {
+        String parentId = DocumentsContract.getDocumentId(parentUri);
+        String childId = DocumentsContract.getDocumentId(childUri);
+        return childId != null && parentId != null && childId.startsWith(parentId + "%2F");
+    }
+
+
     private DocumentFile fromUri(String uriStr) {
         try {
             // Decode once if double-encoded