Parameters

Skills, scripts, monitors, even the application, everything is a parameter. By inheriting from other parameters and including sub-parameters inside them, everything is able to be represented.

Defined at file models/parameters.xml in package pitasc_library.

General structure

Chain of prototype based inheritance. base is the basic parameter prototype, which contains the meta data description and visibility.

any_parameter --> base --> descriptive

All parameters are inheriting from ‘base’.

Basic parameters contain the following attributes inside the <type> tag.

Attributes inside `<type>` tag
Attribute	Description
id	Needs to be locally unique to allow identification, If not unique, a incrementing element e.g., “_no0”, “_no1”, “_no2”, … will be added
data_type	Data type of the parameter, can’t be changed once set
prototype	The base type the parameter “inherits” from, e.g. “string_parameter”.

Basic parameters contain the following parameters inside the <meta> tag by default.

Members inside `<meta>` tag
description	Description of the parameter
visibility	Visibility of the parameter (one of: required, basic, expert, hidden)

The xml definition of a parameter basically looks like the following:

<type id="{Choose unique id}" prototype="{Add parent id}" data_type="{Choose data type}">  <!-- reference would be added here -->
    <meta>
        <member id="description"> {Choose meaningful description} </member>
        <member id="visibility"> {Choose enum} </member>
    </meta>
    <data> {data depending on parameter type} </data>
</type>

For example, this is the definition of a frame parameter (from the pitasc library):

<type id="frame" prototype="string_parameter">
    <meta>
        <member id="description">A frame (coordinate system)</member>
        <clone prototype="restrictions">
            <clone prototype="blacklist"> </clone>
        </clone>
    </meta>
</type>

The blacklist restriction with a space defines that the value of the parameter must not be empty. See below for more information on restrictions.

data_type vs prototype

data_type describes the actual representation of the data of the parameter. It can only be one of the following:

int
bool
float
string
csv:int, csv:bool, csv:float, csv:string
dict
list:{parameter type} ({parameter type can be any pitasc parameter type, e.g. list:frame)
parameter (this is basically saying “don’t know yet, will be defined in inherting parameters”)
parameter:{parameter type} ({parameter type can be any pitasc parameter type, e.g. parameter:monitor)

prototype needs to be an existing pitasc parameter type, defined with <type id="...". Usually a pitasc parameter type sets the data_type already, so if you derive from anything else than prototype="base", you do not need to set the data_type. However if you want to set it, e.g., because you want to create a parameter containing a list of frames, you need to set it and set the prototype to base (data_type="list:frame" prototype="base")

Parameter basic types

Basic type parameters can be used though inheritance. The following parameter basic types are available.

List of basic parameter prototypes
Prototype	Description
bool_parameter	A boolean parameter
int_parameter	An integer parameter
float_parameter	A floating point number parameter
dictionary	A dictionary parameter (assoziative array)

List of string datatypes
Prototype	Description
string_like_parameter	A parameter that behaves like a string
string_concatenation	A list of strings that is concatenated to a single string (children of string_like_parameter)
string_parameter	A string parameter (children of string_like_parameter)

List of string list datatypes
Prototype	Description
string_list_like_parameter	A parameter that behaves like a string or string list
string_list_concatenation	A list of strings and string lists that is concatenated to a single string list (children of string_list_like_parameter)
string_list	A list of strings (children of string_list_like_parameter)

List of csv datatypes
Prototype	Description
bool_csv	A comma-separated list of booleans
int_csv	A comma-separated list of integers
float_csv	A comma-separated list of floats
string_csv	A comma-separated list of strings

Restrictions

Restrictions are used to restrict the values a parameter can assume.

The following restrictions are available.

List of possible restrictions
Restriction type	Description
enum	An enumeration of strings allowed for this parameter
blacklist	An enumeration of strings not allowed for this parameter
int_max	Upper boundary for a int parameter
int_min	Lower boundary for a int parameter
int_csv_max	Upper boundaries for the values of a csv int list
int_csv_min	Lower boundaries for the values of a csv int list
float_max	Upper boundary for a float parameter
float_min	Lower boundary for a float parameter
float_csv_max	Upper boundaries for the values of a csv float list
float_csv_min	Lower boundaries for the values of a csv float list

Add restrictions to a parameter by adding them inside the <meta> tag.

<meta>
    ...
    <clone prototype="restrictions">                        <!-- list of restrictions -->
        <clone prototype="enum">x, y, z, a, b, c</clone>    <!-- example restriction -->
    </clone>
</meta>

Lists & Naming

Naming

In lists, it can happen that two elements would get the same name (id). Consider the following example:

<member id="skills">
    <clone prototype="skill_lin" />
    <clone prototype="skill_lin" />
    <clone prototype="skill_lin" />
</member>

In this case, pitasc changes the id of the skills such that they are unique. The assigned ids of the skills are then

<member id="skills">
    <clone id="skill_lin" prototype="skill_lin" />
    <clone id="skill_lin_no0" prototype="skill_lin" />
    <clone id="skill_lin_no1" prototype="skill_lin" />
</member>

Replacing

Currently, it is not possible to remove entries from a list by using xml syntax. So, if a prototype adds something to a list, e.g. a controller to controllers, and you want to add your own controller, you need to re-define the whole skill to have only your controller in its controller members (below tasks.tracking).

Note