请求提供Node.js下载Trello卡片附件的示例代码

Hey Marc, great question! I’ve put together a practical example and some key insights to help you download attachments from Trello cards using Node.js. Let’s dive in.

Prerequisites #

• A Trello API Key and Token: Grab these from your Trello account settings (under the API section) — generate a key first, then create a token with at least read permissions to access card attachments.
• Node.js installed on your machine.

Step 1: Install Dependencies #

We’ll use axios for making HTTP requests and Node’s built-in fs/promises for file handling. Install axios via npm:

npm install axios

Step 2: Full Example Code #

Here’s a complete script that fetches all attachments from a specific Trello card and saves them to a local folder:

const axios = require('axios');
const fs = require('fs').promises;
const path = require('path');

// Replace these with your own credentials and target card ID
const TRELLO_API_KEY = 'your-api-key-here';
const TRELLO_API_TOKEN = 'your-api-token-here';
const CARD_ID = 'your-target-card-id';

async function downloadTrelloAttachments() {
  try {
    // Fetch all attachments from the card
    const attachmentsResponse = await axios.get(`https://api.trello.com/1/cards/${CARD_ID}/attachments`, {
      params: {
        key: TRELLO_API_KEY,
        token: TRELLO_API_TOKEN,
        fields: 'url,name' // Only request data we need: download URL and file name
      }
    });

    const attachments = attachmentsResponse.data;
    if (attachments.length === 0) {
      console.log('No attachments found on this card.');
      return;
    }

    // Create a directory to save attachments (if it doesn't exist)
    const saveDirectory = './trello-attachments';
    await fs.mkdir(saveDirectory, { recursive: true });

    // Download each attachment one by one
    for (const attachment of attachments) {
      const downloadUrl = attachment.url;
      const fileName = attachment.name;
      const savePath = path.join(saveDirectory, fileName);

      console.log(`Starting download: ${fileName}`);
      
      // Fetch the file as a stream to handle large files efficiently
      const fileStream = await axios({
        url: downloadUrl,
        method: 'GET',
        responseType: 'stream'
      });

      // Write the stream to a local file
      await fs.writeFile(savePath, fileStream.data);
      console.log(`Successfully saved: ${savePath}`);
    }

    console.log('All attachments downloaded successfully! 🎉');
  } catch (error) {
    console.error('Oops, something went wrong:', error.message);
    // Print additional API error details if available
    if (error.response) {
      console.error('API Status Code:', error.response.status);
      console.error('API Error Message:', error.response.data);
    }
  }
}

// Run the function
downloadTrelloAttachments();

Key Concepts & Tips #

• Trello API Endpoint: The /1/cards/{cardId}/attachments endpoint returns all attachments for a card. We specify fields: 'url,name' to keep the response lightweight.
• Card ID: Find your card ID in the Trello card’s URL — it’s the string after /c/ (e.g., in https://trello.com/c/xyz789/my-card, xyz789 is the card ID).
• Stream Handling: Using responseType: 'stream' ensures we don’t load large files into memory all at once, which is better for performance.
• Error Handling: The script catches common issues like invalid credentials, missing cards, or network errors, and prints helpful details to debug.
• Alternative Libraries: If you prefer not to use axios, you can use Node.js’s native fetch (available in Node 18+) or the node-fetch package — the core logic will stay the same.

How to Use the Script #

1. Replace the placeholder values (your-api-key-here, your-api-token-here, your-target-card-id) with your actual Trello credentials and card ID.
2. Run the script with node download-trello-attachments.js (or whatever you named the file).
3. Check the trello-attachments folder in your project directory — all your attachments will be there!

内容的提问来源于stack exchange，提问作者marc torne