Parameters

Parameters are uniquely named strings, and it may take a number of them to generate questionnaires from their specifications. This is the parameter set of a questionnaire.

We use parameter set specifications to define the number of kind of parameters that we expect in parameter sets. Naturally, parameter set specifications include one or more parameter specifications, each of which defines:

• an identifier.

• a label.

• a type.

• a free-form description.

• a mandatory flag.

• an optional default value.

The type determines what strings are acceptable for the parameter. The following types are supported:

• any: the type of any string.

• number: the type of whole numbers.

• bool: the type of true and false strings.

• language: the type of the siz official FAO languages (ar, en,es,zh,ru,ar)

note: a language parameter for the language of the questionnaire is automatically included in all parameter set specifications.

We use these parameter and parameter set specifications in user interfaces, to drive the definiton of parameter sets.

We also use them in backend processes to validate parameter sets when we generate questionnaires. We validate that:

• mandatory parameters have values.

• individual parameter values are valid with respect to their type.

Parameter sets are finally recorded in generated questionnaires.