Migrate from deprecated get_preference_hash() (removal in ESPHome 2027.1.0)

[bdraco]

Summary

ESPHome has deprecated get_preference_hash() in 2026.2.0, with removal planned for 2027.1.0. A new make_entity_preference<T>() helper has been added to EntityBase.

When ESPHome implements get_preference_hash_v2() to fix preference hash collisions (e.g. UTF-8 names, names that sanitize identically), the migration logic will be inside make_entity_preference_(). External components that continue using get_preference_hash() directly will not have their preferences automatically migrated, meaning users will lose saved state.

Current usage

This component has a custom get_preference_hash() override in multiple places:

In components/schedule/schedule.h:

uint32_t get_preference_hash() const { return this->get_object_id_hash(); }

In components/schedule/data_sensor.cpp:

uint32_t DataSensor::get_preference_hash() const {
  if (this->parent_schedule_ != nullptr) {
    uint32_t parent_hash = this->parent_schedule_->get_object_id_hash();
    uint32_t label_hash = fnv1_hash(this->label_);
    return parent_hash ^ label_hash;
  }
  return fnv1_hash(this->label_);
}

And the hash is used to create preferences:

uint32_t hash = this->get_preference_hash();
this->array_pref_->create_preference(hash);

Recommended migration

The Schedule class usage is straightforward — replace calls to get_preference_hash() / get_object_id_hash() with make_entity_preference<T>().

The DataSensor class has a custom composite hash (parent object_id XOR label). This doesn't fit the standard make_entity_preference<T>() pattern directly. If DataSensor extends EntityBase, you can use make_entity_preference<T>() directly (it will use the entity's own identity). If the composite key is intentional for disambiguation, you may need to keep a custom approach but should stop relying on get_object_id_hash() which has the same collision problems.

For the simple case:

// Before:
this->pref_ = global_preferences->make_preference<T>(this->get_preference_hash());

// After:
this->pref_ = this->make_entity_preference<T>();

References

• Deprecation PR: [core] Encapsulate entity preference creation to prepare for hash migration esphome/esphome#13505