Abstract base class for all types of questions used in a Form. More...

#include <mitkQuestion.h>

Inheritance diagram for mitk::Forms::Question:

[legend]

Public Member Functions
	Question ()
	Default constructor. More...

virtual	~Question ()
	Virtual destructor. More...

std::string	GetQuestionText () const
	Get the literal question text. More...

void	SetQuestionText (const std::string &question)
	Set the literal question text. More...

bool	IsRequired () const
	Check whether a response to this question is required to complete a form. More...

void	SetRequired (bool required=true)
	Set whether a response to this question is required to complete a form. More...

virtual std::string	GetRequiredText () const
	Get the text that should be displayed to clearly mark a question as required. More...

virtual bool	HasFileResponses () const
	Query whether the responses given to this question are file paths. More...

virtual std::vector< fs::path >	SubmitFileResponses (const fs::path &basePath) const
	Attach response files to submission. More...

Pure virtual functions
Question is an abstract base class. Derive from this class to add a new type of question and override the following pure virtual functions. Please read the full documentation for all of these functions to fully understand implications and requirements. Do not forget to register any new type of question by calling IQuestionFactory::Register() like it is done in this module's activator class. See also IQuestionFactory
virtual std::string	GetType () const =0
	Return the type of a question as string, e.g. "Multiple choice" or "Drop-down". More...

virtual Question *	CreateAnother () const =0
	Create a new instance of the derived question class type. More...

virtual std::vector< std::string >	GetResponsesAsStrings () const =0
	Return the question's response(s) as strings. More...

virtual void	ClearResponses ()=0
	Clear the/all response(s). More...

virtual bool	IsComplete () const =0
	Check if a question is considered to be answered completely. More...

virtual void	FromJSON (const nlohmann::ordered_json &j)=0
	Deserialize from JSON. More...

virtual void	ToJSON (nlohmann::ordered_json &j) const =0
	Serialize to JSON. More...

Detailed Description

Abstract base class for all types of questions used in a Form.

Question defines the common interface shared by every question type in the Forms module. Concrete question types (e.g. ShortAnswerQuestion, CheckboxesQuestion) derive from this class and implement its pure virtual functions.

Please make sure to read the full documentation of the pure virtual functions in particular to fully understand implications and requirements.

See also: Form, IQuestionFactory, TextQuestion, QuestionWithOptions, LinearScaleQuestion, ScreenshotQuestion

Definition at line 37 of file mitkQuestion.h.

Constructor & Destructor Documentation

◆ Question()

mitk::Forms::Question::Question ( )

Default constructor.

Initializes the question as not required with an empty question text.

◆ ~Question()

virtual mitk::Forms::Question::~Question ( )

virtual

Virtual destructor.

Member Function Documentation

◆ ClearResponses()

virtual void mitk::Forms::Question::ClearResponses ( )

pure virtual

Clear the/all response(s).

After calling this method, IsComplete() returns false.

Implemented in mitk::Forms::TextQuestion, mitk::Forms::ScreenshotQuestion, mitk::Forms::QuestionWithOtherOption, mitk::Forms::QuestionWithOptions, and mitk::Forms::LinearScaleQuestion.

◆ CreateAnother()

virtual Question* mitk::Forms::Question::CreateAnother ( ) const

pure virtual

Create a new instance of the derived question class type.

This method is mainly used by IQuestionFactory to create new instances from registered prototype instances based on a type string.

Question* RhetoricalQuestion::CreateAnother() const
{
  return new RhetoricalQuestion;
}

See also: GetType()

Implemented in mitk::Forms::ShortAnswerQuestion, mitk::Forms::ScreenshotQuestion, mitk::Forms::ParagraphQuestion, mitk::Forms::MultipleChoiceQuestion, mitk::Forms::LinearScaleQuestion, mitk::Forms::DropdownQuestion, and mitk::Forms::CheckboxesQuestion.

◆ FromJSON()

virtual void mitk::Forms::Question::FromJSON ( const nlohmann::ordered_json & j )

pure virtual

Deserialize from JSON.

Polymorphism and the use of base class pointers make it necessary to implement serialization through member functions. Using the pure native approach of the "JSON for Modern C++" library via free functions would lead to partially serialized instances of derived classes.

The actual implementation can and should still be located in a corresponding from_json() free function but we also need the indirection through this member function.

void RhetoricalQuestion::FromJSON(const nlohmann::ordered_json& j)
{
  from_json(j, *this);
}

Parameters

[in] j The JSON object to deserialize from.

See also: from_json(const nlohmann::ordered_json& j, Question& q)

Implemented in mitk::Forms::ShortAnswerQuestion, mitk::Forms::ScreenshotQuestion, mitk::Forms::ParagraphQuestion, mitk::Forms::MultipleChoiceQuestion, mitk::Forms::LinearScaleQuestion, mitk::Forms::DropdownQuestion, and mitk::Forms::CheckboxesQuestion.

◆ GetQuestionText()

std::string mitk::Forms::Question::GetQuestionText ( ) const

Get the literal question text.

Returns: The question text string.

◆ GetRequiredText()

virtual std::string mitk::Forms::Question::GetRequiredText ( ) const

virtual

Get the text that should be displayed to clearly mark a question as required.

This text is typically displayed as soon as a response to a required question is missing. The method can be overridden to customize the default text, e.g. for more complex types of questions, where specific guidance is beneficial.

The default implementation returns "This is a required question".

Returns: A human-readable string describing the requirement.

See also: IsComplete()

◆ GetResponsesAsStrings()

virtual std::vector<std::string> mitk::Forms::Question::GetResponsesAsStrings ( ) const

pure virtual

Return the question's response(s) as strings.

This is the single common generic interface for retrieving responses from all types of questions. It is typically used to store responses in text-based formats like CSV.

It is implemented as vector since certain types of questions like a checkboxes question may support multiple responses. Otherwise, return a vector with a single element.

std::vector<std::string> RhetoricalQuestion::GetResponsesAsStrings() const
{
  return { m_Response };
}

Returns: A vector of response strings.

Implemented in mitk::Forms::TextQuestion, mitk::Forms::ScreenshotQuestion, mitk::Forms::QuestionWithOtherOption, mitk::Forms::QuestionWithOptions, and mitk::Forms::LinearScaleQuestion.

◆ GetType()

virtual std::string mitk::Forms::Question::GetType ( ) const

pure virtual

Return the type of a question as string, e.g. "Multiple choice" or "Drop-down".

This method is essential for the deserialization of questions into their correct type, resp. derived class. The type string is used by IQuestionFactory to look up a registered prototype instance of a certain type to create another instance of it.

The type string does not have to match the class name or follow any other convention except for it must be unique amongst all question types. Prefer natural language like in the examples above in case it is used in a user interface to display a question's type.

std::string RhetoricalQuestion::GetType() const
{
  return "Rhetorical";
}

See also: CreateAnother()

Implemented in mitk::Forms::ShortAnswerQuestion, mitk::Forms::ScreenshotQuestion, mitk::Forms::ParagraphQuestion, mitk::Forms::MultipleChoiceQuestion, mitk::Forms::LinearScaleQuestion, mitk::Forms::DropdownQuestion, and mitk::Forms::CheckboxesQuestion.

◆ HasFileResponses()

virtual bool mitk::Forms::Question::HasFileResponses ( ) const

virtual

Query whether the responses given to this question are file paths.

Always returns false - override this method only if necessary. Typically used during submission to determine if any files should be attached.

Returns: true if responses represent file paths, false otherwise.

See also: SubmitFileResponses()

Reimplemented in mitk::Forms::ScreenshotQuestion.

◆ IsComplete()

virtual bool mitk::Forms::Question::IsComplete ( ) const

pure virtual

Check if a question is considered to be answered completely.

This method is typically called when IsRequired() returns true to determine whether the requirements are fulfilled.

Returns: true if the question has a complete response, false otherwise.

Implemented in mitk::Forms::TextQuestion, mitk::Forms::ScreenshotQuestion, mitk::Forms::QuestionWithOtherOption, mitk::Forms::QuestionWithOptions, and mitk::Forms::LinearScaleQuestion.

◆ IsRequired()

bool mitk::Forms::Question::IsRequired ( ) const

Check whether a response to this question is required to complete a form.

Returns: true if the question is required, false otherwise.

◆ SetQuestionText()

void mitk::Forms::Question::SetQuestionText ( const std::string & question )

Set the literal question text.

Parameters

[in] question The question text to display.

◆ SetRequired()

void mitk::Forms::Question::SetRequired ( bool required = true )

Set whether a response to this question is required to complete a form.

A question is not required by default.

Parameters

[in] required Pass true to mark the question as required, false to mark it as optional.

◆ SubmitFileResponses()

virtual std::vector<fs::path> mitk::Forms::Question::SubmitFileResponses ( const fs::path & basePath ) const

virtual

Attach response files to submission.

This method is supposed to be called during submission only if HasFileResponses() returns true. The given base path should then be used to copy any files. The returned paths should be relative to the base path and are used for submission instead of the return value of GetResponsesAsStrings().

The default implementation returns an empty vector.

Parameters

[in] basePath The directory to which response files are copied.

Returns: A vector of file paths relative to basePath.

See also: HasFileResponses()

Reimplemented in mitk::Forms::ScreenshotQuestion.

◆ ToJSON()

virtual void mitk::Forms::Question::ToJSON ( nlohmann::ordered_json & j ) const

pure virtual

Serialize to JSON.

Polymorphism and the use of base class pointers make it necessary to implement serialization through member functions. Using the pure native approach of the "JSON for Modern C++" library via free functions would lead to partially serialized instances of derived classes.

The actual implementation can and should still be located in a corresponding to_json() free function but we also need the indirection through this member function.

void RhetoricalQuestion::ToJSON(nlohmann::ordered_json& j) const
{
  to_json(j, *this);
}

Parameters

[out] j The JSON object to serialize into.

See also: to_json(nlohmann::ordered_json& j, const Question& q)

Implemented in mitk::Forms::ShortAnswerQuestion, mitk::Forms::ScreenshotQuestion, mitk::Forms::ParagraphQuestion, mitk::Forms::MultipleChoiceQuestion, mitk::Forms::LinearScaleQuestion, mitk::Forms::DropdownQuestion, and mitk::Forms::CheckboxesQuestion.

The documentation for this class was generated from the following file:

mitkQuestion.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Question()

◆ ~Question()

Member Function Documentation

◆ ClearResponses()

◆ CreateAnother()

◆ FromJSON()

◆ GetQuestionText()

◆ GetRequiredText()

◆ GetResponsesAsStrings()

◆ GetType()

◆ HasFileResponses()

◆ IsComplete()

◆ IsRequired()

◆ SetQuestionText()

◆ SetRequired()

◆ SubmitFileResponses()

◆ ToJSON()