Obsidian Core Workflow A: Vault Operations

Overview

Primary workflow for Obsidian plugin development: manipulating notes, handling frontmatter, and working with the vault file system.

Prerequisites

• Completed obsidian-install-auth setup
• Understanding of Obsidian's file structure
• Valid development vault configured

Instructions

Step 1: Working with Files (TFile)

import { TFile, TFolder, TAbstractFile, Vault } from 'obsidian';

export class FileOperations {
  constructor(private vault: Vault) {}

  // Get all markdown files
  getAllNotes(): TFile[] {
    return this.vault.getMarkdownFiles();
  }

  // Get file by path
  getNote(path: string): TFile | null {
    const file = this.vault.getAbstractFileByPath(path);
    return file instanceof TFile ? file : null;
  }

  // Read file content
  async readNote(file: TFile): Promise<string> {
    return this.vault.read(file);
  }

  // Read file content as cached (faster, may be stale)
  readNoteCached(file: TFile): string | null {
    return this.vault.cachedRead(file);
  }

  // Modify file content
  async writeNote(file: TFile, content: string): Promise<void> {
    await this.vault.modify(file, content);
  }

  // Create new note
  async createNote(path: string, content: string): Promise<TFile> {
    // Ensure parent folder exists
    const folderPath = path.substring(0, path.lastIndexOf('/'));
    if (folderPath) {
      await this.ensureFolder(folderPath);
    }
    return this.vault.create(path, content);
  }

  // Delete note
  async deleteNote(file: TFile, trash: boolean = true): Promise<void> {
    if (trash) {
      await this.vault.trash(file, false); // Move to system trash
    } else {
      await this.vault.delete(file);
    }
  }

  // Rename/move note
  async renameNote(file: TFile, newPath: string): Promise<void> {
    await this.vault.rename(file, newPath);
  }

  // Ensure folder exists
  private async ensureFolder(path: string): Promise<void> {
    const folder = this.vault.getAbstractFileByPath(path);
    if (!folder) {
      await this.vault.createFolder(path);
    }
  }
}

Step 2: Frontmatter Operations

import { App, TFile, parseYaml, stringifyYaml } from 'obsidian';

export class FrontmatterService {
  constructor(private app: App) {}

  // Extract frontmatter from note
  getFrontmatter(file: TFile): Record<string, any> | null {
    const cache = this.app.metadataCache.getFileCache(file);
    return cache?.frontmatter || null;
  }

  // Parse frontmatter from content
  parseFrontmatter(content: string): { frontmatter: Record<string, any> | null; body: string } {
    const match = content.match(/^---\n([\s\S]*?)\n---\n([\s\S]*)$/);
    if (!match) {
      return { frontmatter: null, body: content };
    }

    try {
      const frontmatter = parseYaml(match[1]);
      return { frontmatter, body: match[2] };
    } catch {
      return { frontmatter: null, body: content };
    }
  }

  // Update frontmatter in file
  async updateFrontmatter(
    file: TFile,
    updates: Record<string, any>
  ): Promise<void> {
    const content = await this.app.vault.read(file);
    const { frontmatter, body } = this.parseFrontmatter(content);

    const newFrontmatter = { ...frontmatter, ...updates };
    const yamlContent = stringifyYaml(newFrontmatter);
    const newContent = `---\n${yamlContent}---\n${body}`;

    await this.app.vault.modify(file, newContent);
  }

  // Remove frontmatter property
  async removeFrontmatterProperty(file: TFile, key: string): Promise<void> {
    const content = await this.app.vault.read(file);
    const { frontmatter, body } = this.parseFrontmatter(content);

    if (frontmatter && key in frontmatter) {
      delete frontmatter[key];
      const yamlContent = stringifyYaml(frontmatter);
      const newContent = `---\n${yamlContent}---\n${body}`;
      await this.app.vault.modify(file, newContent);
    }
  }

  // Get all files with specific frontmatter property
  getFilesWithProperty(property: string, value?: any): TFile[] {
    return this.app.vault.getMarkdownFiles().filter(file => {
      const fm = this.getFrontmatter(file);
      if (!fm || !(property in fm)) return false;
      if (value !== undefined) return fm[property] === value;
      return true;
    });
  }
}

Step 3: Link and Tag Operations

import { App, TFile, CachedMetadata } from 'obsidian';

export class LinkService {
  constructor(private app: App) {}

  // Get all links from a file
  getOutgoingLinks(file: TFile): string[] {
    const cache = this.app.metadataCache.getFileCache(file);
    const links: string[] = [];

    // Wiki-style links [[link]]
    cache?.links?.forEach(link => {
      links.push(link.link);
    });

    // Embeds ![[embed]]
    cache?.embeds?.forEach(embed => {
      links.push(embed.link);
    });

    return [...new Set(links)];
  }

  // Get backlinks (files linking to this file)
  getBacklinks(file: TFile): TFile[] {
    const backlinks: TFile[] = [];
    const resolvedLinks = this.app.metadataCache.resolvedLinks;

    for (const [sourcePath, links] of Object.entries(resolvedLinks)) {
      if (file.path in links) {
        const sourceFile = this.app.vault.getAbstractFileByPath(sourcePath);
        if (sourceFile instanceof TFile) {
          backlinks.push(sourceFile);
        }
      }
    }

    return backlinks;
  }

  // Get all tags from a file
  getTags(file: TFile): string[] {
    const cache = this.app.metadataCache.getFileCache(file);
    const tags: string[] = [];

    // Tags in content
    cache?.tags?.forEach(tag => {
      tags.push(tag.tag);
    });

    // Tags in frontmatter
    const fmTags = cache?.frontmatter?.tags;
    if (Array.isArray(fmTags)) {
      fmTags.forEach(tag => {
        tags.push(tag.startsWith('#') ? tag : `#${tag}`);
      });
    }

    return [...new Set(tags)];
  }

  // Get all files with specific tag
  getFilesWithTag(tag: string): TFile[] {
    const normalizedTag = tag.startsWith('#') ? tag : `#${tag}`;

    return this.app.vault.getMarkdownFiles().filter(file => {
      const tags = this.getTags(file);
      return tags.includes(normalizedTag);
    });
  }

  // Update link in file (when target is renamed)
  async updateLink(
    file: TFile,
    oldLink: string,
    newLink: string
  ): Promise<void> {
    let content = await this.app.vault.read(file);

    // Update wiki links
    content = content.replace(
      new RegExp(`\\[\\[${this.escapeRegex(oldLink)}(\\|[^\\]]*)?\\]\\]`, 'g'),
      (match, alias) => `[[${newLink}${alias || ''}]]`
    );

    await this.app.vault.modify(file, content);
  }

  private escapeRegex(str: string): string {
    return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
  }
}

Step 4: Search and Query

import { App, TFile, prepareFuzzySearch, prepareSimpleSearch } from 'obsidian';

export class SearchService {
  constructor(private app: App) {}

  // Fuzzy search file names
  searchFileNames(query: string): TFile[] {
    const search = prepareFuzzySearch(query);
    const results: { file: TFile; score: number }[] = [];

    for (const file of this.app.vault.getMarkdownFiles()) {
      const match = search(file.basename);
      if (match) {
        results.push({ file, score: match.score });
      }
    }

    return results
      .sort((a, b) => b.score - a.score)
      .map(r => r.file);
  }

  // Simple text search in content
  async searchContent(query: string): Promise<{ file: TFile; matches: number }[]> {
    const search = prepareSimpleSearch(query);
    const results: { file: TFile; matches: number }[] = [];

    for (const file of this.app.vault.getMarkdownFiles()) {
      const content = await this.app.vault.cachedRead(file);
      const match = search(content);
      if (match) {
        results.push({ file, matches: match.matches.length });
      }
    }

    return results.sort((a, b) => b.matches - a.matches);
  }

  // Search by multiple criteria
  async advancedSearch(criteria: {
    folder?: string;
    tags?: string[];
    frontmatter?: Record<string, any>;
    content?: string;
  }): Promise<TFile[]> {
    let files = this.app.vault.getMarkdownFiles();

    // Filter by folder
    if (criteria.folder) {
      files = files.filter(f => f.path.startsWith(criteria.folder!));
    }

    // Filter by tags
    if (criteria.tags?.length) {
      const linkService = new LinkService(this.app);
      files = files.filter(f => {
        const fileTags = linkService.getTags(f);
        return criteria.tags!.every(tag =>
          fileTags.includes(tag.startsWith('#') ? tag : `#${tag}`)
        );
      });
    }

    // Filter by frontmatter
    if (criteria.frontmatter) {
      const fmService = new FrontmatterService(this.app);
      files = files.filter(f => {
        const fm = fmService.getFrontmatter(f);
        if (!fm) return false;
        return Object.entries(criteria.frontmatter!).every(
          ([key, value]) => fm[key] === value
        );
      });
    }

    // Filter by content
    if (criteria.content) {
      const search = prepareSimpleSearch(criteria.content);
      const contentMatches: TFile[] = [];
      for (const file of files) {
        const content = await this.app.vault.cachedRead(file);
        if (search(content)) {
          contentMatches.push(file);
        }
      }
      files = contentMatches;
    }

    return files;
  }
}

Output

• File operations for create, read, update, delete
• Frontmatter parsing and modification
• Link and tag traversal
• Search and query capabilities

Error Handling

Error	Cause	Solution
File not found	Path incorrect	Verify with getAbstractFileByPath
Permission denied	File locked	Check if file is open in editor
YAML parse error	Invalid frontmatter	Validate YAML syntax
Circular links	Recursive backlinks	Track visited files

Examples

Complete Note Template

async function createNoteFromTemplate(
  app: App,
  templatePath: string,
  newPath: string,
  variables: Record<string, string>
): Promise<TFile> {
  const template = app.vault.getAbstractFileByPath(templatePath);
  if (!(template instanceof TFile)) {
    throw new Error('Template not found');
  }

  let content = await app.vault.read(template);

  // Replace variables
  for (const [key, value] of Object.entries(variables)) {
    content = content.replace(new RegExp(`{{${key}}}`, 'g'), value);
  }

  return app.vault.create(newPath, content);
}

Resources

• Obsidian Developer Docs - Vault
• Obsidian MetadataCache

Next Steps

For UI components, see obsidian-core-workflow-b.