# Common Patterns

## List All with Auto-Pagination

**Problem:** API returns paginated results. Default page size is 20.

**Solution:** Use SDK auto-pagination to iterate all results.

```typescript
// TypeScript
for await (const zone of client.zones.list()) {
  console.log(zone.name)
}
```

```python
# Python
for zone in client.zones.list():
    print(zone.name)
```

```go
// Go
iter := client.Zones.ListAutoPaging(ctx, cloudflare.ZoneListParams{})
for iter.Next() {
    fmt.Println(iter.Current().Name)
}
```

## Error Handling with Retry

**Problem:** Rate limits (429) and transient errors need retry.

**Solution:** SDKs auto-retry with exponential backoff. Customize as needed.

```typescript
// Increase retries for rate-limit-heavy operations
const client = new Cloudflare({ maxRetries: 5 })

try {
  const zone = await client.zones.create({
    /* ... */
  })
} catch (err) {
  if (err instanceof Cloudflare.RateLimitError) {
    // Already retried 5 times with backoff
    const retryAfter = err.headers['retry-after']
    console.log(`Rate limited. Retry after ${retryAfter}s`)
  }
}
```

## Batch Parallel Operations

**Problem:** Need to create multiple resources quickly.

**Solution:** Use `Promise.all()` for parallel requests (respect rate limits).

```typescript
// Create multiple DNS records in parallel
const records = ['www', 'api', 'cdn'].map((subdomain) =>
  client.dns.records.create({
    zone_id: 'zone-id',
    type: 'A',
    name: `${subdomain}.example.com`,
    content: '192.0.2.1',
  })
)
await Promise.all(records)
```

**Controlled concurrency** (avoid rate limits):

```typescript
import pLimit from 'p-limit'
const limit = pLimit(10) // Max 10 concurrent

const subdomains = ['www', 'api', 'cdn' /* many more */]
const records = subdomains.map((subdomain) =>
  limit(() =>
    client.dns.records.create({
      zone_id: 'zone-id',
      type: 'A',
      name: `${subdomain}.example.com`,
      content: '192.0.2.1',
    })
  )
)
await Promise.all(records)
```

## Zone CRUD Workflow

```typescript
// Create
const zone = await client.zones.create({
  account: { id: 'account-id' },
  name: 'example.com',
  type: 'full',
})

// Read
const fetched = await client.zones.get({ zone_id: zone.id })

// Update
await client.zones.edit(zone.id, { paused: false })

// Delete
await client.zones.delete(zone.id)
```

## DNS Bulk Update

```typescript
// Fetch all A records
const records = []
for await (const record of client.dns.records.list({
  zone_id: 'zone-id',
  type: 'A',
})) {
  records.push(record)
}

// Update all to new IP
await Promise.all(
  records.map((record) =>
    client.dns.records.update({
      zone_id: 'zone-id',
      dns_record_id: record.id,
      type: 'A',
      name: record.name,
      content: '203.0.113.1', // New IP
      proxied: record.proxied,
      ttl: record.ttl,
    })
  )
)
```

## Filter and Collect Results

```typescript
// Find all proxied A records
const proxiedRecords = []
for await (const record of client.dns.records.list({
  zone_id: 'zone-id',
  type: 'A',
})) {
  if (record.proxied) {
    proxiedRecords.push(record)
  }
}
```

## Error Recovery Pattern

```typescript
async function createZoneWithRetry(name: string, maxAttempts = 3) {
  for (let attempt = 1; attempt <= maxAttempts; attempt++) {
    try {
      return await client.zones.create({
        account: { id: 'account-id' },
        name,
        type: 'full',
      })
    } catch (err) {
      if (err instanceof Cloudflare.RateLimitError && attempt < maxAttempts) {
        const retryAfter = parseInt(err.headers['retry-after'] || '5')
        console.log(`Rate limited, waiting ${retryAfter}s (retry ${attempt}/${maxAttempts})`)
        await new Promise((resolve) => setTimeout(resolve, retryAfter * 1000))
      } else {
        throw err
      }
    }
  }
}
```

## Conditional Update Pattern

```typescript
// Only update if zone is active
const zone = await client.zones.get({ zone_id: 'zone-id' })
if (zone.status === 'active') {
  await client.zones.edit(zone.id, { paused: false })
}
```

## Batch with Error Handling

```typescript
// Process multiple zones, continue on errors
const results = await Promise.allSettled(zoneIds.map((id) => client.zones.get({ zone_id: id })))

results.forEach((result, i) => {
  if (result.status === 'fulfilled') {
    console.log(`Zone ${i}: ${result.value.name}`)
  } else {
    console.error(`Zone ${i} failed:`, result.reason.message)
  }
})
```

## See Also

- [api.md](./api.md) - SDK client initialization, basic operations
- [gotchas.md](./gotchas.md) - Rate limits, common errors
- [configuration.md](./configuration.md) - SDK configuration options