Calculated properties allow you to add or remove properties to a :term:`variable`
or a :term:`family` depending on the context.
Here is the list of editable properties:
..list-table::
:widths:15 15 25
:header-rows:1
* - **Attribute applicable on**
-**Property's name**
- Comment
* - Variable
Family
- hidden
- Hides a variable or a family, in this case it is not accessible in `read-write` mode,
but remains accessible in a calculation or in `read-only` mode
* - Variable
Family
- disabled
- Deactivates a variable or family, in this case it is never accessible
* - Variable
- mandatory
- The variable expects a value other than `None` or `[]` for multiple variables
A property can be calculated. In this case we have two possibilities:
- calculation via Jinja
- calculation via a variable
Parameters
---------------
..list-table::
:widths:15 25 20 15
:header-rows:1
* - **Calculation type**
-**Parameter**
-**Comment**
-**Sample**
* -
-**type**
`string`
`mandatory`
- Calculation type, possible values are: jinja, variable, information, suffix or index
- jinja
* - Jinja
-**jinja**
`string`
`mandatory`
- Jinja template . For a multiple variable, each line represents a value.
- {% if rougail.variable %}
{{ rougail.variable }}
{% endif %}
* - Jinja
-**params**
`list`
- Additional parameters passed to the Jinja template
-
* - Variable
-**variable**
`string`
`mandatory`
- Name of the associated variable.
..attention:: The variable must be of `boolean` type.
- rougail.variable
* - Variable
-**propertyerror**
`boolean`
- If access to the variable is not possible due to a property
(for example `disabled`) by default an error is returned.
If the attribute is `False`, the calculated value is False.
**Default value**: `True`
- False
In the case of a Jinja type calculation, it is possible to have parameters.
There are two types of parameter:
- the standard parameters (string, boolean, integer, null), in this case just do: "key: value"
- advanced settings:
- parameter via a variable
- parameter via information
- parameter via a suffix: in the case of a variable in a dynamic family
- parameter via an index: in the case of a follower variable
..list-table::
:widths:15 25 20 15
:header-rows:1
* - **Parameter's type**
-**Parameter**
-**Comments**
-**Sample**
* -
-**name**
`string`
`mandatory`
- parameter's name
- my_param
* -
-**type**
`string`
`mandatory`
- Parameter's type, possible values are: variable, information, suffix or index
- suffix
* - Variable
-**variable**
`string`
`mandatory`
- variable's name
- rougail.variable
* - Variable (`mandatory`) Information
-**propertyerror**
`boolean`
- If access to the variable is not possible due to a property (for example `disabled`) by default an error is returned. If the attribute is False, the parameter is not passed to the Jinja template.
**Default value**: `True`
- False
* - Variable
-**optional**
`boolean`
- The variable may not exist depending on YAML file imports. If the optional parameter is True, the parameter will simply be deleted if the variable does not exist.
**Default value**: `False`
- True
* - information
-**information**
`string`
`mandatory`
- Name of the information whose value we want to retrieve.
{% if rougail.condition and rougail.condition == "hide!" %}
this rougail.condition value is 'hide!'
{% endif %}
In this case the variable is hidden if the value of the variable "rougail.condition" is `hide!` and it did not hide for any other value. Be careful, always take into consideration that "rougail.condition" can be equal to `None`.
The message returned by the function is visible in the error message in the event of an access problem:
..code-block:: python
>>> from rougail import Rougail, RougailConfig
>>> RougailConfig['dictionaries_dir'] = ['dict']
>>> rougail = Rougail()
>>> config = rougail.get_config()
>>> config.property.read_write()
[..]
tiramisu.error.PropertiesOptionError: cannot access to option "my_variable" because has property "hidden" (this rougail.condition value is 'hide!')
It is possible to use parameters when calculating properties as for calculating the `default` attribute.
A calculated property of variable type
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A variable can therefore be calculated via the result of another variable. Please note, this other variable must be of `boolean` type:
