calculated default value

docs/tutorial/boolean.rst

@@ -277,6 +277,74 @@ It is possible to add a `variable` parameter to the `hidden` attribute like this
           type: port
           default: 8080
 
+A calculated default value
+-------------------------------
+
+
+There is something left in the https configuration mode of the proxy: 
+
+- if the use of the proxy variables for https are the same of the proxy variables for http, 
+  that is, if `use_for_https` is true, the https configuration variables are hidden, that's OK. 
+- if the use of the proxy variables for https **are not** the same of the proxy variables for http, 
+  we would like to set their default values to the http proxy variables values.
+
+By now, the default settings are set like this: 
+
+.. code-block:: yaml
+
+    port:
+      description: HTTPS Port
+      type: port
+      default: 8080
+
+
+
+The dynamic setting of a default can be achieved in this way:  
+
+.. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_035/firefox/20-manual.yml
+   :language: yaml
+   :caption: A default variable's value dynamically set 
+
+..
+    ---
+    manual:
+
+      use_for_https:
+        description: Also use this proxy for HTTPS
+        default: true
+
+      https_proxy:
+        description: HTTPS Proxy
+        hidden:
+          variable: manual.use_for_https
+
+        address:
+          description: HTTPS address
+          type: domainname
+          params:
+            allow_ip: true
+          default:
+            variable: manual.http_proxy.address
+
+        port:
+          description: HTTPS Port
+          type: port
+          default:
+            variable: manual.http_proxy.port
+
+.. note:: This is just a pointer to another variable's value.
+
+The default values of the https address and port are pointing to the value of 
+the `manual.http_proxy.address` and the `manual.http_proxy.port` variables. 
+
+.. glossary::
+
+   calculated
+   
+       We say that a variable's value or a default variable's value is calculated 
+       when there is a pointer which refers to another variable's value 
+       or if there is some :term:`jinja` code or a python function that calculates it. 
+
 .. keypoints:: Key points
 
     **Keywords**
@@ -284,6 +352,7 @@ It is possible to add a `variable` parameter to the `hidden` attribute like this
     - The :term:`hidden` property set to a family
     - The fact that a property can be set dynamically
     - The conditional dependency of a `hidden` property that depends on a `boolean` variable.
+    - A calculated default value 
     
     **Progress**
 

docs/tutorial/index.rst

@@ -43,5 +43,7 @@ At first glance we can see that we have a selection of five configuration option
    proxymode
    disabled
    boolean
+  
+.. 
    tutorial