How Often Does the ReClip Frontend Poll for Download Status?

The ReClip frontend polls the server for download status exactly once every second (1000 milliseconds) using a JavaScript setInterval timer defined in the pollCard function.

ReClip is an open-source YouTube downloader that provides real-time download progress updates through its web interface. When a user initiates a video download, the frontend begins actively monitoring the job status through HTTP polling to provide immediate visual feedback. Understanding this polling frequency helps developers optimize network usage and diagnose latency issues within the averygan/reclip codebase.

The 1-Second Polling Mechanism

The polling interval is hardcoded in templates/index.html at line 555, where the pollCard function establishes a recurring timer to check download progress. According to the ReClip source code, this interval is set to 1000 milliseconds (1 second), balancing real-time updates with server load.

// Located in templates/index.html, line 555
const iv = setInterval(async () => {
  const res = await fetch(`/api/status/${c.jobId}`);
  const data = await res.json();
  
  // Status handling logic omitted for brevity
}, 1000);  // 1000ms = 1 second polling interval

How Status Polling Works in ReClip

The polling lifecycle involves three distinct phases: initiation, execution, and termination.

Initiating the Download with dlCard

When a user starts a download, the dlCard function handles the initial request and stores the returned jobId. It then immediately invokes pollCard to begin monitoring the job's progress on the frontend.

The pollCard Polling Loop

Inside pollCard, the code creates a setInterval timer assigned to the variable iv. Every 1000 milliseconds, the interval triggers an asynchronous fetch request to the /api/status/<jobId> endpoint. The response data updates the UI elements to reflect current download progress.

// Simplified flow from templates/index.html
await dlCard(index);   // Stores jobId and triggers polling

// Inside pollCard function:
const iv = setInterval(async () => {
  const res = await fetch(`/api/status/${c.jobId}`);
  const data = await res.json();

  if (data.status === 'done') {
    clearInterval(iv);        // Stop polling on completion
    // Handle completed download UI updates
  } else if (data.status === 'error') {
    clearInterval(iv);        // Stop polling on failure
    // Handle error state UI updates
  }
}, 1000);  // Fixed 1-second interval

Termination Conditions

The polling loop automatically terminates when the backend returns a terminal status. Specifically, the frontend checks for two conditions:

• status === 'done': The download completed successfully
• status === 'error': The download encountered a failure

Upon detecting either state, the code executes clearInterval(iv) to stop further network requests and prevent memory leaks or unnecessary server load.

Backend Support in app.py

The Flask backend in app.py exposes the /api/status/<job_id> endpoint that the frontend polls every second. This endpoint returns a JSON object containing the current job state, which the pollCard function parses to determine whether to continue polling or clear the interval.

Summary

• Polling Frequency: The ReClip frontend polls for download status every 1000 milliseconds (1 second).
• Core Function: pollCard in templates/index.html (line 555) controls the polling mechanism.
• API Endpoint: Frontend requests hit /api/status/<jobId> to retrieve current status.
• Auto-Stop Logic: Polling automatically stops when status equals 'done' or 'error' via clearInterval.

Frequently Asked Questions

What is the exact polling interval used by ReClip?

The ReClip frontend uses a fixed 1000-millisecond (1-second) polling interval. This value is hardcoded as the second argument to setInterval in the pollCard function within templates/index.html.

Which JavaScript function controls the download status polling?

The pollCard function controls all download status polling. It is invoked by dlCard after a download job is initiated, and it manages the setInterval timer that queries the backend every second.

How does ReClip stop polling when a download completes?

ReClip stops polling by calling clearInterval(iv) when the backend response contains status: 'done' or status: 'error'. This prevents unnecessary network requests and potential memory leaks once the job reaches a terminal state.

Where is the polling logic located in the source code?

The polling logic resides in templates/index.html at line 555, specifically within the pollCard function. The corresponding backend endpoint that handles these requests is defined in app.py.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}