[h2zero]

• feat(NimBLEServer): add registerServicesFirst() to place app services at low handles

By default the standard GAP (0x1800) and GATT (0x1801) services register first and take the low attribute handles (0x0001+), with the application's services placed after them. Some peripherals must instead expose their own services at the low handles — e.g. when emulating a device whose central addresses attributes by hardcoded handle rather than by discovery.

Add an opt-in NimBLEServer::registerServicesFirst(bool) setter (default false, so existing behavior is unchanged) that defers GAP/GATT registration until after the application services in resetGATT(), giving the application services the low handles. The device-name/appearance restore that follows ble_gatts_reset() is factored into a small lambda so it stays correct in either order. #

Summary by CodeRabbit

• New Features
  • Added an option to choose whether application services or standard GAP/GATT services are registered first, affecting their attribute handle order.
• Bug Fixes
  • Device name and appearance are preserved across GATT resets in non-component builds.
  • Standard GAP/GATT services are initialized even if application service startup fails when registration is deferred.

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Walkthrough

Arr, NimBLEServer now lets applications choose whether application services or GAP/GATT register first. GATT reset preserves the device name and appearance in non-component builds. Startup also changes a conditional initializer and removes Aggregate Format descriptor population.

Changes: Arr, GATT registration flow

Layer / File(s)	Summary
Configure and apply registration order src/NimBLEServer.h, src/NimBLEServer.cpp	Arr, the public registerAppServicesFirst(bool) option controls whether application services register before GAP/GATT. GATT reset preserves the device name and appearance in non-component builds. If an application service fails to start, deferred GAP/GATT initialization still runs.
Adjust other server startup behavior src/NimBLEServer.cpp	Arr, m_advertiseOnDisconnect is initialized only when extended advertising is disabled and the broadcaster role is enabled. The startup traversal that populated Aggregate Format descriptors from active Presentation Format handles is removed.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant NimBLEServer
  participant ApplicationServices
  participant GAPGATT
  alt Application services register first
    NimBLEServer->>ApplicationServices: Start application services
    alt Application service start fails
      NimBLEServer->>GAPGATT: Initialize GAP/GATT
    else Application services start successfully
      NimBLEServer->>GAPGATT: Initialize GAP/GATT
    end
  else GAP/GATT register first
    NimBLEServer->>GAPGATT: Initialize GAP/GATT
    NimBLEServer->>ApplicationServices: Start application services
  end

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Possibly related PRs

• h2zero/NimBLE-Arduino#1054: Arr, this PR added the Aggregate Format descriptor population loop that this change removes.

Suggested reviewers: srgg

Merge Risk: Moderate · previous review d8ba4

Applications relying on automatically populated Aggregate Format descriptors will expose empty handle lists to connected clients. Restore that behavior before merging.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff with cyclomatic complexity of at least 2. Documenta…	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly describes the main change: adding a setter that registers application services first so they receive low attribute handles. The method name in the title differs from the implemented …
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Title check

Explanation

The title clearly describes the main change: adding a setter that registers application services first so they receive low attribute handles. The method name in the title differs from the implemented API, which is registerAppServicesFirst(bool), but the title remains related and understandable.

Full details: Docstring Coverage

Explanation

Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff with cyclomatic complexity of at least 2. Documentation-only edits and deletions within surviving functions are included; unchanged diff context and fully deleted functions are excluded. Analyzed 4 functions across 2 files.

Resolution

Write docstrings for the functions missing them to satisfy the coverage threshold.

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_{Arr, choose which services claim handles first
GAP and GATT may lead the way
Or app services sail ahead
Names and appearances weather reset
Failed starts still bring GAP and GATT
The old descriptor loop sets sail away}

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Actionable comments posted: 1

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• Fix comments: Fix CodeRabbit comments on this PR

Prompt to fix review comments

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Inline comments:
Review comments at @src/NimBLEServer.cpp:
- Line 325: Restore Aggregate Format (0x2905) value population in
NimBLEServer::start() after the #endif and before the services-changed
indication. Traverse registered services and characteristics, and populate each
0x2905 descriptor with the handles of its active 0x2904 descriptors, preserving
the existing behavior on every start.

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• src/NimBLEServer.cpp
• src/NimBLEServer.h

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