Evernote SDK Patterns

Overview

Production-ready patterns for working with the Evernote SDK, including search with NoteFilter, pagination, attachments, tags, error handling wrappers, and batch operations with rate limit handling.

Prerequisites

• Completed evernote-install-auth and evernote-hello-world
• Understanding of Evernote data model (Notes, Notebooks, Tags, Resources)
• Familiarity with async/await and Promises

Instructions

Pattern 1: Search with NoteFilter

Use NoteFilter for query terms and sort order, paired with NotesMetadataResultSpec to select returned fields. This avoids fetching full note content when only metadata is needed.

javascript
const filter = new Evernote.NoteStore.NoteFilter({
  words: 'tag:important notebook:Work',
  ascending: false,
  order: Evernote.Types.NoteSortOrder.UPDATED
});

const spec = new Evernote.NoteStore.NotesMetadataResultSpec({
  includeTitle: true, includeUpdated: true,
  includeTagGuids: true, includeNotebookGuid: true
});

const result = await noteStore.findNotesMetadata(filter, 0, 100, spec);

Pattern 2: Creating Notes with Attachments

Compute the MD5 hash of the file buffer, create a Resource with the binary data and MIME type, embed it in ENML with <en-media type="..." hash="..."/>, and attach it to the note.

javascript
const hash = crypto.createHash('md5').update(fileBuffer).digest('hex');
const resource = new Evernote.Types.Resource();
resource.data = new Evernote.Types.Data();
resource.data.body = fileBuffer;
resource.mime = 'image/png';

const note = new Evernote.Types.Note();
note.title = 'Note with Attachment';
note.content = wrapInENML(`<en-media type="image/png" hash="${hash}"/>`);
note.resources = [resource];
await noteStore.createNote(note);

Pattern 3: Error Handling Wrapper

Wrap API calls to distinguish EDAMUserException (client errors), EDAMSystemException (rate limits, maintenance), and EDAMNotFoundException (invalid GUIDs). Use error.rateLimitDuration for automatic retry delays.

Pattern 4: Batch Operations

Process items sequentially with configurable delay between operations. On rate limit errors, wait for rateLimitDuration seconds then retry. Track progress with callbacks.

Pattern 5: Tag and Notebook Management

Implement getOrCreateTag() and getOrCreateNotebook() for idempotent operations. Use listTags() / listNotebooks() to check existence before creating.

For all nine patterns with complete implementations, see Implementation Guide.

Output

• Search patterns using NoteFilter and NotesMetadataResultSpec
• Async generator for paginated note retrieval
• Attachment creation with MD5 hash and MIME type
• Tag and notebook find-or-create utilities
• EvernoteError wrapper class with isRateLimit, isNotFound, isInvalidData
• Batch processor with rate limit retry and progress tracking

Error Handling

| Error | Cause | Solution | |-------|-------|----------| | RATE_LIMIT_REACHED | Too many API calls | Use rateLimitDuration, add delays between batch items | | BAD_DATA_FORMAT | Invalid ENML | Validate with wrapInENML() before sending | | DATA_CONFLICT | Concurrent modification | Refetch note metadata and retry update | | QUOTA_REACHED | Account storage full | Check remaining quota via user.accounting |

Resources

• API Reference
• Search Grammar
• Core Concepts
• JavaScript SDK

Next Steps

See evernote-core-workflow-a for note creation and management workflows.

Examples

Bulk tagging: Search for all notes matching a query, then batch-add a tag to each result with 200ms delay between operations and automatic rate limit retry.

Attachment upload: Read a PDF from disk, compute its MD5 hash, create a note with the PDF as an <en-media> resource, and verify the upload via getNote() with withResources: true.