Fixes image upload failures

Improved the image upload process by adding error handling for network issues, increasing upload timeout, and setting a maximum file size limit. Specifically, modified `app.py` to set `MAX_CONTENT_LENGTH` and `UPLOAD_TIMEOUT`, and updated `static/js/upload.js` to include a timeout and error handling within the fetch request.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: c7b687d7-8856-49d8-87a3-9d7f3f6499f6
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/d7727d0d-3b25-49de-9476-c76c61abfa65/5db894a3-8b66-4603-922a-3c556a1b1242.jpg

app.py

@@ -13,6 +13,8 @@ logging.basicConfig(level=logging.DEBUG)
 # Create Flask app
 app = Flask(__name__)
 app.secret_key = os.environ.get("SESSION_SECRET", "dev_secret_key")
+app.config['MAX_CONTENT_LENGTH'] = 30 * 1024 * 1024  # Limit uploads to 30MB
+app.config['UPLOAD_TIMEOUT'] = 120  # Increase upload timeout
 
 # Configure upload folder
 UPLOAD_FOLDER = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'uploads')

static/js/upload.js

@@ -46,10 +46,23 @@ uploadForm.addEventListener('submit', function(event) {
     formData.append('file', file);
     formData.append('feature_type', featureTypeSelect.value);
     
-    // Upload the file
+    // Upload the file - add error handling for network issues
     fetch('/upload', {
         method: 'POST',
-        body: formData
+        body: formData,
+        // Add timeout for large uploads
+        timeout: 120000, // 2 minutes timeout
+        // Add credentials for session cookies
+        credentials: 'same-origin'
+    }).catch(error => {
+        console.error('Network error occurred:', error);
+        processingStatus.classList.add('d-none');
+        if (error.name === 'AbortError') {
+            showError('Upload timed out. Try a smaller file or check your connection.');
+        } else {
+            showError('Network error: ' + error.message);
+        }
+        throw error;
     })
     .then(response => {
         if (!response.ok) {