Action Modules & Menu Segments

Two separate concerns for exposing service functionality to users:

• Action modules — register commands (keyboard / command palette)
• Menu segments — build context menu items (right-click, pane menus)

Both close over service deps. Both colocate with their feature domain. For the underlying service architecture, see the obsidian-services skill.

Action Modules

Each domain owns its action module. No centralized ActionService. Each feature exports an add*Actions(plugin, deps) function as the entry point convention. Internally, action modules are free to organize however makes sense: define command descriptors, register disposables via plugin.register(...), set up repeat-key handlers, etc. The convention is the entry point shape, not the implementation.

File placement

Colocate with the service: services/<domain>/actions.ts

Shape

// services/database/actions.ts
export function addDatabaseActions(
  plugin: ZotLitPlugin,
  deps: { db: DatabaseService },
) {
  plugin.addCommand({
    id: "zotlit:refresh-db",
    name: "Refresh Zotero database",
    callback: async () => {
      try {
        await deps.db.ready;
        await deps.db.refresh();
      } catch {
        new Notice("Database is not available");
      }
    },
  });
}

Graceful degradation

Command handlers check service.ready at invocation time. If the backing service failed to init, the command shows a notice rather than crashing:

try {
  await deps.db.ready;
  // ... do work
} catch {
  new Notice("Database is not available");
}

onError (in ServiceContainer) handles detailed error reporting. Consumers only need to know whether the service is available.

editorCheckCallback pattern

For commands that only apply in certain editor contexts, use editorCheckCallback. The checking parameter separates visibility from execution:

plugin.addCommand({
  id: "zotlit:update-literature-note",
  name: "Update literature note",
  editorCheckCallback(checking, _editor, ctx) {
    if (!ctx.file || !isLiteratureNote(ctx.file, plugin.app)) return false;
    if (checking) return true;
    void (async () => {
      try {
        await deps.db.ready;
        const itemKey = getItemKeyOf(ctx.file!, plugin.app.metadataCache);
        if (!itemKey) {
          new Notice("Cannot get Zotero item key from file");
          return;
        }
        // ... update logic
      } catch {
        new Notice("Database is not available");
      }
    })();
  },
});

Wiring in onload()

Action modules are called unconditionally in onload() after buildServices:

addDatabaseActions(this, { db: services.db });
addNoteActions(this, { db: services.db, noteIndex: services.noteIndex });
addCitationActions(this, { db: services.db, settings: services.settings });

Menu Segments

No wrapper around Menu. Obsidian's imperative-declarative API (.addItem(i => i.setTitle(...).onClick(...))) is already clean enough. The only abstraction is a shared function signature and a unified context type.

MenuSegment type

A segment is a function that may add zero or more items to a menu based on context. No class, no interface beyond this. Returns true if it rendered any items, false otherwise — composites use this to skip separators or avoid empty submenu wrappers:

type MenuSegment = (menu: Menu, ctx: ItemMenuContext) => boolean;

ItemMenuContext — unified menu context

Different menu events provide different raw data. ItemMenuContext normalizes them into a discriminated union separating event kind from menu source:

type PaneMenuSource = 'more-options' | 'tab-header' | 'sidebar-context-menu';

type ItemMenuContext = {
  file: TFile | undefined;
  itemKey: string | undefined;
  isLitNote: boolean;
} & (
  | { kind: 'editor'; source: 'editor' }
  | { kind: 'file'; source: string }
  | { kind: 'pane'; source: PaneMenuSource }
);

kind distinguishes event origin for routing; only routing logic should inspect it. source carries the Obsidian-provided source string (especially useful for pane menus). Domain fields (file, itemKey, isLitNote) are resolved once — feature segments inspect these, never raw event args.

resolveItemContext

Converts raw Obsidian event args into ItemMenuContext:

function resolveItemContext(
  app: App,
  ctx:
    | { kind: 'editor'; file: TFile | null | undefined }
    | { kind: 'file'; file: TAbstractFile; source: string }
    | { kind: 'pane'; source: PaneMenuSource; file: TFile | null | undefined },
): ItemMenuContext {
  const file = ctx.file instanceof TFile ? ctx.file : undefined;
  const base = {
    file,
    itemKey: file ? getItemKeyOf(file, app.metadataCache) : undefined,
    isLitNote: !!file && isLiteratureNote(file, app),
  };
  switch (ctx.kind) {
    case 'editor': return { ...base, kind: 'editor', source: 'editor' };
    case 'file':   return { ...base, kind: 'file', source: ctx.source };
    case 'pane':   return { ...base, kind: 'pane', source: ctx.source };
  }
}

To add a new context dimension (e.g., editor selection state), extend the relevant union branch — segments gain access automatically.

Writing a segment

Each feature exports a factory that closes over deps and returns a MenuSegment. File placement: services/<domain>/menu.ts

// services/note-index/menu.ts
import type { DatabaseService } from "../database/service";
import type { NoteIndexService } from "./service";

interface NoteMenuDeps {
  db: DatabaseService;
  noteIndex: NoteIndexService;
}

export function noteMenuSegment(deps: NoteMenuDeps): MenuSegment {
  return (menu, ctx) => {
    if (!ctx.itemKey) return false;

    menu.addItem((item) =>
      item
        .setSection("zotlit")
        .setTitle("Open in Zotero")
        .setIcon("external-link")
        .onClick(async () => {
          try {
            await deps.db.ready;
            // ...
          } catch {
            new Notice("Database is not available");
          }
        }),
    );

    if (ctx.source !== "tab-header") {
      menu.addItem((item) =>
        item
          .setSection("zotlit")
          .setTitle("Update literature note")
          .setIcon("refresh-cw")
          .onClick(async () => {
            try {
              await deps.db.ready;
              // ...
            } catch {
              new Notice("Database is not available");
            }
          }),
      );
    }
    return true;
  };
}

Visibility logic (the if checks) lives inside the segment — the feature decides what to show where. The segment returns false when irrelevant, so composites can react to empty contributions without pre-filtering.

Rules

Menu construction is synchronous. Never await during segment execution. Obsidian builds menus in one tick. Only onClick handlers may be async.

Use setSection() with a consistent section key on all items so they cluster together regardless of insertion order.

Return the boolean. false when the segment adds nothing (e.g., no itemKey). Composites depend on this.

Visibility uses sync state only. Services may provide a synchronous readiness accessor (e.g., a getter or method) that reflects whether init has completed, failed, or is still pending — implementation is up to the service. If a service is still loading, disable the item with a placeholder title (e.g., "Loading…") using that synchronous state — don't await inside the segment body.

Composing segments

Segments are composed into a single callable. Ordering is explicit:

// services/menu.ts
export function buildMenuSegments(services: Services): MenuSegment {
  const segments = [
    noteMenuSegment({ db: services.db, noteIndex: services.noteIndex }),
    citationMenuSegment({ db: services.db, settings: services.settings }),
    templateMenuSegment({ db: services.db, settings: services.settings }),
  ];
  return (menu, ctx) => {
    let rendered = false;
    for (const seg of segments) {
      if (seg(menu, ctx)) rendered = true;
    }
    return rendered;
  };
}

Wiring to Obsidian events

Registration happens in onload(). Custom workspace events and DOM-based menu hooks also live in onload() for now; extract to a dedicated service if the wiring grows complex.

const zotlitMenu = buildMenuSegments(services);

this.registerEvent(
  this.app.workspace.on("editor-menu", (menu, _editor, info) => {
    zotlitMenu(menu, resolveItemContext(this.app, { kind: "editor", file: info.file }));
  }),
);

this.registerEvent(
  this.app.workspace.on("file-menu", (menu, file, source) => {
    zotlitMenu(menu, resolveItemContext(this.app, { kind: "file", file, source }));
  }),
);

For view onPaneMenu (not a workspace event — called by Obsidian on the view instance). The view receives the composite segment via deps (closure capture in registerView factory):

onPaneMenu(menu: Menu, source: string) {
  super.onPaneMenu(menu, source);
  this.#zotlitMenu(menu, resolveItemContext(
    this.app, { kind: "pane", source: source as PaneMenuSource, file: this.file },
  ));
}

Relationship Between Actions and Menus

Action modules and menu segments are separate concerns that may share the same underlying operation. Menu items may call app.commands.executeCommandById() to reuse command logic, but direct invocation is also fine when the menu handler needs different args or flow.

Shared Context Resolution

Shared context resolution (e.g., "which item is the current note about?") lives in utility functions (getItemKeyOf, isLiteratureNote), not a service — it's stateless frontmatter lookup.

View Degradation

Views also check service.ready at open time:

async onOpen() {
  try {
    await this.#db.ready;
    // render normally
  } catch {
    // render unavailable state
  }
}