---
name: evernote-sdk-patterns
description: |
  Advanced Evernote SDK patterns and best practices.
  Use when implementing complex note operations, batch processing,
  search queries, or optimizing SDK usage.
  Trigger with phrases like "evernote sdk patterns", "evernote best practices",
  "evernote advanced", "evernote batch operations".
allowed-tools: Read, Write, Edit, Grep
version: 1.0.0
license: MIT
author: Jeremy Longshore <jeremy@intentsolutions.io>
---

# Evernote SDK Patterns

## Overview

Production-ready patterns for working with the Evernote SDK, including search, filtering, batch operations, and resource handling.

## Prerequisites

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

## Core Patterns

### Pattern 1: Search with NoteFilter

```javascript
const Evernote = require('evernote');

async function searchNotes(noteStore, searchQuery, maxResults = 100) {
  // Create filter with search grammar
  const filter = new Evernote.NoteStore.NoteFilter({
    words: searchQuery,
    ascending: false,
    order: Evernote.Types.NoteSortOrder.UPDATED
  });

  // Specify which metadata to return
  const spec = new Evernote.NoteStore.NotesMetadataResultSpec({
    includeTitle: true,
    includeContentLength: true,
    includeCreated: true,
    includeUpdated: true,
    includeTagGuids: true,
    includeNotebookGuid: true
  });

  // Find notes (offset, maxNotes)
  const result = await noteStore.findNotesMetadata(filter, 0, maxResults, spec);

  console.log(`Found ${result.totalNotes} notes (returned ${result.notes.length})`);
  return result;
}

// Usage examples:
// searchNotes(noteStore, 'tag:important notebook:Work');
// searchNotes(noteStore, 'intitle:meeting created:day-7');
// searchNotes(noteStore, 'todo:false'); // Unchecked todos
```

### Pattern 2: Search Grammar Queries

```javascript
// Build complex search queries
function buildSearchQuery(options = {}) {
  const parts = [];

  if (options.notebook) {
    parts.push(`notebook:"${options.notebook}"`);
  }

  if (options.tags && options.tags.length) {
    options.tags.forEach(tag => parts.push(`tag:"${tag}"`));
  }

  if (options.excludeTags && options.excludeTags.length) {
    options.excludeTags.forEach(tag => parts.push(`-tag:"${tag}"`));
  }

  if (options.createdAfter) {
    parts.push(`created:${formatDateForSearch(options.createdAfter)}`);
  }

  if (options.updatedAfter) {
    parts.push(`updated:${formatDateForSearch(options.updatedAfter)}`);
  }

  if (options.inTitle) {
    parts.push(`intitle:"${options.inTitle}"`);
  }

  if (options.hasAttachments) {
    parts.push('resource:*');
  }

  if (options.hasTodos !== undefined) {
    parts.push(`todo:${options.hasTodos}`);
  }

  if (options.text) {
    parts.push(options.text);
  }

  // Use 'any:' for OR logic, default is AND
  if (options.matchAny) {
    return 'any: ' + parts.join(' ');
  }

  return parts.join(' ');
}

function formatDateForSearch(date) {
  // Format: YYYYMMDD
  return date.toISOString().slice(0, 10).replace(/-/g, '');
}

// Example: Find notes tagged "urgent" in "Work" notebook from last week
const query = buildSearchQuery({
  notebook: 'Work',
  tags: ['urgent'],
  createdAfter: new Date(Date.now() - 7 * 24 * 60 * 60 * 1000)
});
// Result: 'notebook:"Work" tag:"urgent" created:20240115'
```

### Pattern 3: Paginated Note Retrieval

```javascript
async function* getAllNotesMetadata(noteStore, filter, spec, pageSize = 100) {
  let offset = 0;
  let hasMore = true;

  while (hasMore) {
    const result = await noteStore.findNotesMetadata(filter, offset, pageSize, spec);

    for (const note of result.notes) {
      yield note;
    }

    offset += result.notes.length;
    hasMore = offset < result.totalNotes;

    console.log(`Progress: ${offset}/${result.totalNotes}`);
  }
}

// Usage with async iteration
async function processAllNotes(noteStore) {
  const filter = new Evernote.NoteStore.NoteFilter({ words: 'tag:process' });
  const spec = new Evernote.NoteStore.NotesMetadataResultSpec({
    includeTitle: true,
    includeUpdated: true
  });

  for await (const note of getAllNotesMetadata(noteStore, filter, spec)) {
    console.log(`Processing: ${note.title}`);
    // Process each note
  }
}
```

### Pattern 4: Efficient Note Content Retrieval

```javascript
async function getNoteWithOptions(noteStore, noteGuid, options = {}) {
  const {
    withContent = true,
    withResources = false,
    withRecognition = false,
    withAlternateData = false
  } = options;

  return noteStore.getNote(
    noteGuid,
    withContent,
    withResources,        // Include binary resource data
    withRecognition,      // Include OCR data
    withAlternateData     // Include alternate representations
  );
}

// Only get content (most common)
const note = await getNoteWithOptions(noteStore, guid);

// Get note with all attachments
const noteWithFiles = await getNoteWithOptions(noteStore, guid, {
  withResources: true
});
```

### Pattern 5: Creating Notes with Attachments

```javascript
const crypto = require('crypto');
const fs = require('fs');
const path = require('path');

async function createNoteWithAttachment(noteStore, title, content, filePath) {
  const Evernote = require('evernote');

  // Read file and compute hash
  const fileBuffer = fs.readFileSync(filePath);
  const hash = crypto.createHash('md5').update(fileBuffer).digest('hex');
  const mimeType = getMimeType(filePath);

  // Create resource (attachment)
  const resource = new Evernote.Types.Resource();
  resource.data = new Evernote.Types.Data();
  resource.data.body = fileBuffer;
  resource.data.size = fileBuffer.length;
  resource.data.bodyHash = Buffer.from(hash, 'hex');
  resource.mime = mimeType;

  // Set file attributes
  resource.attributes = new Evernote.Types.ResourceAttributes();
  resource.attributes.fileName = path.basename(filePath);

  // Create ENML with embedded resource
  const enml = `<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE en-note SYSTEM "http://xml.evernote.com/pub/enml2.dtd">
<en-note>
  ${content}
  <en-media type="${mimeType}" hash="${hash}"/>
</en-note>`;

  // Create note
  const note = new Evernote.Types.Note();
  note.title = title;
  note.content = enml;
  note.resources = [resource];

  return noteStore.createNote(note);
}

function getMimeType(filePath) {
  const ext = path.extname(filePath).toLowerCase();
  const mimeTypes = {
    '.png': 'image/png',
    '.jpg': 'image/jpeg',
    '.jpeg': 'image/jpeg',
    '.gif': 'image/gif',
    '.pdf': 'application/pdf',
    '.txt': 'text/plain',
    '.doc': 'application/msword',
    '.docx': 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
  };
  return mimeTypes[ext] || 'application/octet-stream';
}
```

### Pattern 6: Working with Tags

```javascript
async function getOrCreateTag(noteStore, tagName) {
  // Try to find existing tag
  const tags = await noteStore.listTags();
  const existing = tags.find(t =>
    t.name.toLowerCase() === tagName.toLowerCase()
  );

  if (existing) {
    return existing;
  }

  // Create new tag
  const tag = new Evernote.Types.Tag();
  tag.name = tagName;
  return noteStore.createTag(tag);
}

async function addTagsToNote(noteStore, noteGuid, tagNames) {
  // Get current note
  const note = await noteStore.getNote(noteGuid, false, false, false, false);

  // Resolve tag names to GUIDs
  const tagGuids = await Promise.all(
    tagNames.map(async name => {
      const tag = await getOrCreateTag(noteStore, name);
      return tag.guid;
    })
  );

  // Merge with existing tags
  const existingTags = note.tagGuids || [];
  const allTags = [...new Set([...existingTags, ...tagGuids])];

  // Update note
  note.tagGuids = allTags;
  return noteStore.updateNote(note);
}
```

### Pattern 7: Notebook Operations

```javascript
async function getOrCreateNotebook(noteStore, notebookName, stack = null) {
  const notebooks = await noteStore.listNotebooks();
  const existing = notebooks.find(n =>
    n.name.toLowerCase() === notebookName.toLowerCase()
  );

  if (existing) {
    return existing;
  }

  const notebook = new Evernote.Types.Notebook();
  notebook.name = notebookName;
  if (stack) {
    notebook.stack = stack;
  }

  return noteStore.createNotebook(notebook);
}

async function moveNoteToNotebook(noteStore, noteGuid, notebookName) {
  const notebook = await getOrCreateNotebook(noteStore, notebookName);
  const note = await noteStore.getNote(noteGuid, false, false, false, false);

  note.notebookGuid = notebook.guid;
  return noteStore.updateNote(note);
}
```

### Pattern 8: Error Handling Wrapper

```javascript
class EvernoteError extends Error {
  constructor(originalError) {
    super(originalError.message || 'Evernote API error');
    this.name = 'EvernoteError';
    this.code = originalError.errorCode;
    this.parameter = originalError.parameter;
    this.rateLimitDuration = originalError.rateLimitDuration;
    this.original = originalError;
  }

  get isRateLimit() {
    return this.code === Evernote.Errors.EDAMErrorCode.RATE_LIMIT_REACHED;
  }

  get isNotFound() {
    return this.code === Evernote.Errors.EDAMErrorCode.UNKNOWN;
  }

  get isInvalidData() {
    return this.code === Evernote.Errors.EDAMErrorCode.BAD_DATA_FORMAT;
  }
}

async function withErrorHandling(operation) {
  try {
    return await operation();
  } catch (error) {
    if (error.errorCode !== undefined) {
      throw new EvernoteError(error);
    }
    throw error;
  }
}

// Usage
try {
  const note = await withErrorHandling(() =>
    noteStore.getNote(guid, true, false, false, false)
  );
} catch (error) {
  if (error instanceof EvernoteError && error.isRateLimit) {
    console.log(`Rate limited. Retry in ${error.rateLimitDuration}s`);
  }
}
```

### Pattern 9: Batch Operations with Rate Limit Handling

```javascript
async function batchProcess(items, operation, options = {}) {
  const {
    concurrency = 1,  // Keep at 1 to avoid rate limits
    delayMs = 100,
    onProgress = () => {}
  } = options;

  const results = [];
  let processed = 0;

  for (const item of items) {
    try {
      const result = await operation(item);
      results.push({ success: true, item, result });
    } catch (error) {
      if (error.rateLimitDuration) {
        // Wait for rate limit to clear
        console.log(`Rate limited, waiting ${error.rateLimitDuration}s...`);
        await sleep(error.rateLimitDuration * 1000);
        // Retry
        const result = await operation(item);
        results.push({ success: true, item, result });
      } else {
        results.push({ success: false, item, error });
      }
    }

    processed++;
    onProgress(processed, items.length);

    // Add delay between operations
    if (processed < items.length) {
      await sleep(delayMs);
    }
  }

  return results;
}

const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));

// Usage
const notes = await searchNotes(noteStore, 'tag:archive');
const results = await batchProcess(
  notes.notes,
  note => noteStore.deleteNote(note.guid),
  {
    delayMs: 200,
    onProgress: (done, total) => console.log(`${done}/${total}`)
  }
);
```

## Output

- Reusable SDK patterns for common operations
- Efficient search with NoteFilter
- Pagination for large result sets
- Attachment handling with proper MIME types
- Tag and notebook management utilities
- Production error handling

## Error Handling

| Error | Cause | Solution |
|-------|-------|----------|
| `RATE_LIMIT_REACHED` | Too many API calls | Use rateLimitDuration, add delays |
| `BAD_DATA_FORMAT` | Invalid ENML | Validate before sending |
| `DATA_CONFLICT` | Concurrent modification | Refetch and retry |
| `QUOTA_REACHED` | Account storage full | Check user's remaining quota |

## Resources

- [API Reference](https://dev.evernote.com/doc/reference/)
- [Search Grammar](https://dev.evernote.com/doc/articles/search_grammar.php)
- [Core Concepts](https://dev.evernote.com/doc/articles/core_concepts.php)

## Next Steps

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