Allow setting set_percentage and set_preset_mode of template fan without turning on (#23822)

Co-authored-by: Franck Nijhof <frenck@frenck.nl>

source/_integrations/fan.template.markdown

@@ -13,6 +13,8 @@ The `template` platform creates fans that combine integrations and provides the
 ability to run scripts or invoke services for each of the `turn_on`, `turn_off`, `set_percentage`,
 `set_preset_mode`, `set_oscillating`, and `set_direction` commands of a fan.
 
+## Configuration
+
 To enable Template Fans in your installation, add the following to your
 `configuration.yaml` file:
 
@@ -146,3 +148,110 @@ When converting a fan with 3 speeds from the old fan entity model, the following
 33 - `low`
 66 - `medium`
 100 - `high`
+
+## Examples
+
+### Helper Fan
+
+This example uses an input_boolean and an input_number to mimic a fan, and 
+the example shows multiple service calls for set_percentage.  
+
+{% raw %}
+
+```yaml
+fan:
+  - platform: template
+    fans:
+      helper_fan:
+        friendly_name: "Helper Fan"
+        value_template: "{{ states('input_boolean.state') }}"
+        turn_on:
+          - service: input_boolean.turn_on
+            target:
+              entity_id: input_boolean.state
+        turn_off:
+          - service: input_boolean.turn_off
+            target:
+              entity_id: input_boolean.state
+        percentage_template: >
+          {{ states('input_number.percentage') if is_state('input_boolean.state', 'on') else 0 }}
+        speed_count: 6
+        set_percentage:
+          - service: input_boolean.turn_{{ 'on' if percentage > 0 else 'off' }}
+            target:
+              entity_id: input_boolean.state
+          - service: input_number.set_value
+            target:
+              entity_id: input_number.percentage
+            data:
+              value: "{{ percentage }}"
+```
+
+{% endraw %}
+
+### Preset Modes Fan
+
+This example uses an existing fan with only a percentage. It extends the 
+percentage value into useable preset modes without a helper entity.
+
+{% raw %}
+
+```yaml
+fan:
+  - platform: template
+    fans:
+      preset_mode_fan:
+        friendly_name: "Preset Mode Fan Example"
+        value_template: "{{ states('fan.percentage_fan') }}"
+        turn_on:
+          - service: fan.turn_on
+            target:
+              entity_id: fan.percentage_fan
+        turn_off:
+          - service: fan.turn_off
+            target:
+              entity_id: fan.percentage_fan
+        percentage_template: >
+          {{ state_attr('fan.percentage_fan', 'percentage') }}
+        speed_count: 3
+        set_percentage:
+          - service: fan.set_percentage
+            target:
+              entity_id: fan.percentage_fan
+            data:
+              percentage: "{{ percentage }}"
+        preset_modes:
+          - "off"
+          - "low"
+          - "medium"
+          - "high"
+        preset_mode_template: >
+          {% if is_state('fan.percentage_fan', 'on') %}
+            {% if state_attr('fan.percentage_fan', 'percentage') == 100  %}
+              high
+            {% elif state_attr('fan.percentage_fan', 'percentage') == 66 %}
+              medium
+            {% else %}
+              low
+            {% endif %}
+          {% else %}
+            off
+          {% endif %}
+        set_preset_mode:
+          - service: fan.set_percentage
+            target:
+              entity_id: fan.percentage_fan
+            data:
+              percentage: >-
+                {% if preset_mode == 'high' %}
+                  100
+                {% elif preset_mode == 'medium' %}
+                  66
+                {% elif preset_mode == 'low' %}
+                  33
+                {% else %}
+                  0
+                {% endif %}
+```
+
+{% endraw %}