API integratie best practices voor moderne applicaties

async function apiCallWithRetry(url, options, maxRetries = 3) { let lastError; for (let i = 0; i < maxRetries; i++) { try { const response = await fetch(url, options); if (response.ok) { return await response.json(); } // Don't retry on client errors if (response.status >= 400 && response.status < 500) { throw new Error(`Client error: ${response.status}`); } lastError = new Error(`Server error: ${response.status}`); } catch (error) { lastError = error; } // Exponential backoff const delay = Math.min(1000 * Math.pow(2, i), 10000); await new Promise(resolve => setTimeout(resolve, delay)); } throw lastError; }

class TokenManager { constructor(clientId, clientSecret, tokenEndpoint) { this.clientId = clientId; this.clientSecret = clientSecret; this.tokenEndpoint = tokenEndpoint; this.token = null; this.tokenExpiry = null; } async getToken() { // Return cached token if still valid if (this.token && this.tokenExpiry > Date.now() + 60000) { return this.token; } // Request new token const response = await fetch(this.tokenEndpoint, { method: 'POST', headers: { 'Content-Type': 'application/x-www-form-urlencoded', 'Authorization': 'Basic ' + btoa(`${this.clientId}:${this.clientSecret}`) }, body: 'grant_type=client_credentials' }); const data = await response.json(); this.token = data.access_token; this.tokenExpiry = Date.now() + (data.expires_in * 1000); return this.token; } }