QuestionImageModel

Specifies a value for the alt attribute of the underlying <img> element.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

QuestionImageModel

Empties the errors array.

Type:

() => void

Implemented in:

Question

See also:

errors

Specifies when to clear the question value if the question becomes invisible.

Possible values:

• "default" (default) - Inherits the setting from the Survey's clearInvisibleValues property.
• "onHidden" - Clears the value when the question becomes invisible. If a question is invisible on startup and has an initial value, this value will be cleared when the survey is complete.
• "onHiddenContainer" - Clears the value when the question or its container (page or panel) becomes invisible. If a question is invisible on startup and has an initial value, this value will be cleared when the survey is complete.
• "onComplete" - Clears the value when the survey is complete.
• "none" - Never clears the value of an invisible question.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

default

Accepted values:

default , none , onComplete , onHidden , onHiddenContainer

Implemented in:

Question

See also:

SurveyModel.clearInvisibleValues * , visible * , SurveyModel.onComplete

Removes values that cannot be assigned to this question, for example, choices unlisted in the choices array.

Call this method after you assign new question values in code to ensure that they are acceptable.

This method does not remove values that fail validation. Call the validate() method to validate newly assigned values.

Type:

() => void

Implemented in:

Question

See also:

validate

Sets the question's value and comment properties to undefined.

Type:

(keepComment?: boolean) => void

Parameters:

keepComment, type: boolean

Implemented in:

Question

See also:

value * , comment

Creates a new object that has the same type and properties as the current SurveyJS object.

Type:

() => Base

Implemented in:

Base

Collapses the survey element.

In collapsed state, the element displays only title and description.

Type:

() => void

Implemented in:

SurveyElement

See also:

title * , description * , state * , toggleState * , expand * , isCollapsed * , isExpanded

A comment to the selected question value. Enable the showCommentArea property to allow users to leave comments.

Type:

string writable

Implemented in:

Question

See also:

showCommentArea * , commentText

A placeholder for the comment area. Applies when the showCommentArea property is true.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

showCommentArea * , comment * , commentText

Specifies a caption displayed above the comment area. Applies when the showCommentArea property is true.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

showCommentArea * , comment

Returns true if the survey element or its child elements have validation errors.

This property contains the result of the most recent validation. This result may be outdated. Call the validate method to get an up-to-date value.

Type:

boolean readonly

Implemented in:

SurveyElement

See also:

errors

Specifies the type of content that the Image question displays.

Possible values:

• "image" - An image in one of the following formats: JPEG, GIF, PNG, APNG, SVG, BMP, ICO.
• "video" - A video in one of the following formats: MP4, MOV, WMV, FLV, AVI, MKV.
• "youtube" - A link to a YouTube video.
• "auto" (default) - Selects one of the above based on the imageLink property.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

auto

Accepted values:

auto , image , video , youtube

Implemented in:

QuestionImageModel

A correct answer to this question. Specify this property if you want to create a quiz.

Type:

any writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

SurveyModel.getCorrectAnswerCount * , SurveyModel.getInCorrectAnswerCount

Returns an object in which keys are UI elements and values are CSS classes applied to them.

Use the following events of the SurveyModel object to override CSS classes:

• onUpdateQuestionCssClasses
• onUpdatePanelCssClasses
• onUpdatePageCssClasses
• onUpdateChoiceItemCss

Type:

any readonly

Implemented in:

SurveyElement

A default value for the question. Ignored for question types that cannot have a value (for example, HTML).

The default value is used as a question value in the following cases:

• While the survey is being loaded from JSON.
• The question is just added to the survey and does not yet have an answer.
• The respondent left the answer empty.

Type:

any writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

defaultValueExpression

An expression used to calculate the defaultValue.

This expression applies until the question value is specified by an end user or programmatically.

An expression can reference other questions as follows:

• {other_question_name}
• {panel.other_question_name} (to access questions inside the same dynamic panel)
• {row.other_question_name} (to access questions inside the same dynamic matrix or multi-column dropdown)

An expression can also include built-in and custom functions for advanced calculations. For example, if the defaultValue should be today's date, set the defaultValueExpression to "today()", and the corresponding built-in function will be executed each time the survey is loaded. Refer to the following help topic for more information: Built-In Functions.

View Demo

Type:

any writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

defaultValue * , setValueExpression

Explanatory text displayed under the title.

Type:

string writable

Implemented in:

SurveyElementCore

See also:

hasDescription

Specifies where to display a question description.

Possible values:

• "default" (default) - Inherits the setting from the Survey's questionDescriptionLocation property.
• "underTitle" - Displays the description under the question title.
• "underInput" - Displays the description under the interactive area.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

default

Accepted values:

default , underInput , underTitle

Implemented in:

Question

See also:

description * , hasDescription

A Boolean expression. If it evaluates to false, this question becomes read-only.

A survey parses and runs all expressions on startup. If any values used in the expression change, the survey re-evaluates it.

Refer to the following help topic for more information: Conditional Visibility.

View Demo

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

readOnly * , isReadOnly

Specifies the error message position. Overrides the questionErrorLocation property specified for the question's container (survey, page, or panel).

Possible values:

• "default" (default) - Inherits the setting from the questionErrorLocation property specified for the question's container.
• "top" - Displays error messages above questions.
• "bottom" - Displays error messages below questions.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

default

Accepted values:

default , top , bottom

Implemented in:

Question

Validation errors. Call the validate() method to validate survey element data.

Type:

SurveyError[] writable

Implemented in:

SurveyElement

See also:

validate

Expands the survey element.

Type:

() => void

Implemented in:

SurveyElement

See also:

state * , toggleState * , collapse * , isCollapsed * , isExpanded

Moves focus to the input field of this question.

Type:

(onError?: boolean, scrollIfVisible?: boolean) => void

Parameters:

onError, type: boolean ,

Pass true if you want to focus an input field with the first validation error. Default value: false (focuses the first input field). Applies to question types with multiple input fields.

scrollIfVisible, type: boolean

Implemented in:

Question

Assigns a new configuration to the current SurveyJS object. This configuration is taken from a passed JSON object.

The JSON object should contain only serializable properties of this SurveyJS object. Event handlers and properties that do not belong to the SurveyJS object are ignored.

Type:

(json: any, options?: ILoadFromJSONOptions) => void

Parameters:

json, type: any ,

A JSON object with properties that you want to apply to the current SurveyJS object.

options, type: ILoadFromJSONOptions ,

An object with configuration options.

Implemented in:

Base

See also:

toJSON

Returns a display text that corresponds to the question value. For example, if you call this method for a Dropdown question, it returns an item text instead of an item value.

Type:

(keysAsText: boolean, value?: any) => any

Parameters:

keysAsText, type: boolean ,

Applies when the question value is an object (in Matrix, Multiple Text, and similar questions). Pass true if not only values in the object should be display texts, but also keys. Default value: false.

value, type: any ,

Specify this parameter to get a display text for a specific value, not for the current question value. If the question value is an object, this parameter should be a similar object.

Implemented in:

Question

Returns the survey's locale.

If a default locale is used, this method returns an empty string. To get the applied locale in this case, use the following code:

import { surveyLocalization } from 'survey-core';
const defaultLocale = surveyLocalization.defaultLocale;

Type:

() => string

Implemented in:

SurveyElement

See also:

Localization & Globalization

Returns an array of questions nested within the current question. Use this method to obtain questions within Multiple Text, Dynamic Panel, and Matrix-like questions.

Type:

(visibleOnly?: boolean) => Question[]

Parameters:

visibleOnly, type: boolean ,

A Boolean value that specifies whether to include only visible nested questions.

Return Value:

An array of nested questions.

Implemented in:

Question

Returns the question value as an object in which the question name, title, value, and other parameters are stored as individual properties.

If the question can have more than one value (Matrix, Multiple Text), the object enables the isNode flag and stores information about these values in the data property. Refer to the following help topic for more information: Access Full Survey Results.

Pass an object with the includeEmpty property set to false if you want to skip empty answers.

Type:

(options?: IPlainDataOptions) => IQuestionPlainData

Parameters:

options, type: IPlainDataOptions

Implemented in:

Question

Returns a JsonObjectProperty object with metadata about a serializable property that belongs to the current SurveyJS object.

If the property is not found, this method returns null.

Type:

(propName: string) => JsonObjectProperty

Parameters:

propName, type: string ,

A property name.

Implemented in:

Base

Returns the value of a property with a specified name.

If the property is not found or does not have a value, this method returns either undefined, defaultValue specified in the property configuration, or a value passed as the defaultValue parameter.

Type:

(name: string, defaultValue?: any) => any

Parameters:

name, type: string ,

A property name.

defaultValue, type: any ,

(Optional) A value to return if the property is not found or does not have a value.

Implemented in:

Base

Returns title location calculated based on the question's titleLocation property and the questionTitleLocation property of the question's containers (survey, page, or panel).

Type:

() => string

Implemented in:

Question

See also:

titleLocation * , SurveyModel.questionTitleLocation

Returns the question type. Possible values:

• "boolean"
• "checkbox"
• "comment"
• "dropdown"
• "tagbox"
• "expression"
• "file"
• "html"
• "image"
• "imagepicker"
• "matrix"
• "matrixdropdown"
• "matrixdynamic"
• "multipletext"
• "panel"
• "paneldynamic"
• "radiogroup"
• "rating"
• "ranking"
• "signaturepad"
• "text"

Type:

() => string

Implemented in:

Question

Returns true if the survey element has a description.

Type:

boolean readonly

Implemented in:

SurveyElementCore

See also:

description

Returns false if the question has no input fields (HTML, Image, and similar question types).

Type:

boolean readonly

Implemented in:

Question

See also:

hasSingleInput

Returns false if the question has no input fields (HTML, Image) or has multiple input fields (Matrix, Multiple Text).

Type:

boolean readonly

Implemented in:

Question

See also:

hasInput

Returns false if the titleLocation property is set to "hidden" or if the question cannot have a title (for example, an HTML question).

If the title property is undefined or set to an empty string, the hasTitle property returns true, because the question uses its name as a title in this case.

Type:

boolean readonly

Implemented in:

Question

See also:

title * , titleLocation

Hides the question number from the title and excludes the question from numbering.

If you want to disable question numbering in the entire survey, set SurveyModel's showQuestionNumbers property to false.

Type:

boolean writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

SurveyModel.showQuestionNumbers

A value to assign to the id attribute of the rendered HTML element. A default id is generated automatically.

Type:

string writable

Implemented in:

Question

Specifies how to resize the image or video to fit it into its container.

Refer to the object-fit CSS property description for information on accepted values.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

contain

Accepted values:

none , contain , cover , fill

Implemented in:

QuestionImageModel

See also:

imageHeight * , imageWidth

Specifies the height of a container for the image or video. Accepts positive numbers and CSS values.

Default value: 150

Use the imageFit property to specify how to fit the image or video into the container.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

150

Implemented in:

QuestionImageModel

See also:

imageWidth * , imageFit

Specifies an image or video URL.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

QuestionImageModel

See also:

contentMode

Specifies the width of a container for the image or video. Accepts positive numbers and CSS values.

Default value: 200

Use the imageFit property to specify how to fit the image or video into the container.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

200

Implemented in:

QuestionImageModel

See also:

imageHeight * , imageFit

Increases or decreases an indent of survey element content from the left edge. Accepts positive integer values and 0. Does not apply in the Default V2 theme.

Type:

number writable

Implemented in:

SurveyElement

See also:

rightIndent

Returns true if the object is included in a survey.

This property may return false, for example, when you create a survey model dynamically.

Type:

boolean readonly

Implemented in:

Base

Returns true if the question can display its title to the left of the input field.

Type:

boolean readonly

Implemented in:

Question

See also:

titleLocation * , getTitleLocation * , hasTitle

Returns true if a question answer matches the correctAnswer property value.

View Demo

Type:

() => boolean

Implemented in:

Question

See also:

correctAnswer * , SurveyModel.getQuizQuestions

Returns true if the survey element is collapsed.

Type:

boolean readonly

Implemented in:

SurveyElement

See also:

state * , toggleState * , collapse * , expand * , isExpanded

Use this method to find out if the current object is of a given typeName or inherited from it.

Type:

(typeName: string) => boolean

Parameters:

typeName, type: string ,

One of the values listed in the getType() description.

Return Value:

true if the current object is of a given typeName or inherited from it.

Implemented in:

Base

See also:

getType

Returns true if the survey is being designed in Survey Creator.

Type:

boolean readonly

Implemented in:

Base

Returns true if the question value is an empty string, array, or object or if it equals undefined or null.

Type:

() => boolean

Implemented in:

Question

Returns true if the survey element is expanded.

Type:

boolean readonly

Implemented in:

SurveyElement

See also:

state * , toggleState * , collapse * , expand * , isCollapsed

Returns true if the object configuration is being loaded from JSON.

Type:

boolean readonly

Implemented in:

Base

Returns true if the survey element is a page.

Type:

boolean readonly

Implemented in:

SurveyElementCore

See also:

Base.getType

Returns true if the survey element is a panel.

Type:

boolean readonly

Implemented in:

SurveyElementCore

See also:

Base.getType

Returns true if a parent element (page or panel) is visible.

Type:

boolean readonly

Implemented in:

Question

Returns true if the survey element is a question.

Type:

boolean readonly

Implemented in:

SurveyElementCore

See also:

Base.getType

Returns true if the survey element or its parent element is read-only.

If you want to switch a survey element to the read-only state based on a condition, specify the enableIf property. Refer to the following help topic for information: Conditional Visibility.

Type:

boolean readonly

Implemented in:

SurveyElement

See also:

readOnly

Makes the question required. If a respondent skips a required question, the survey displays a validation error.

Type:

boolean writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

requiredIf * , Data Validation

Returns true if the element is a survey.

Type:

boolean readonly

Implemented in:

SurveyElementCore

See also:

Base.getType

Returns true if a passed value is an empty string, array, or object or if it equals to undefined or null.

Type:

(value: any, trimString?: boolean) => boolean

Parameters:

value, type: any ,

A value to be checked.

trimString, type: boolean ,

(Optional) When this parameter is true, the method ignores whitespace characters at the beginning and end of a string value. Pass false to disable this functionality.

Implemented in:

Base

Returns true if the question is visible or the survey is currently in design mode.

If you want to display or hide a question based on a condition, specify the visibleIf property. Refer to the following help topic for information: Conditional Visibility.

Type:

boolean readonly

Implemented in:

Question

See also:

visibleIf * , visible * , isParentVisible

Gets or sets maximum survey element width in CSS values.

Default value: "100%" (taken from settings.maxWidth)

Type:

string writable

Implemented in:

SurveyElement

See also:

minWidth * , renderWidth * , width

Gets or sets minimum survey element width in CSS values.

Default value: "300px" (taken from settings.minWidth)

Type:

string writable

Implemented in:

SurveyElement

See also:

maxWidth * , renderWidth * , width

A survey element identifier.

Question names must be unique.

Type:

string writable

Implemented in:

SurveyElement

A question number or letter (depends on the questionStartIndex property of the question container (panel, page, or survey)).

When the question number, title, or the entire question is invisible, this property returns an empty string.

Type:

string readonly

Implemented in:

Question

See also:

SurveyModel.questionStartIndex * , hideNumber * , titleLocation * , visibleIf

An event that is raised when an ItemValue property is changed.

Parameters:

• sender: this
  A SurveyJS object whose property contains an array of ItemValue objects.
• options.obj: ItemValue
  An ItemValue object.
• options.propertyName: string
  The name of the property to which an array of ItemValue objects is assigned (for example, "choices" or "rows").
• options.name: "text" | "value"
  The name of the changed property.
• options.newValue: any
  A new value for the property.

Type:

Event<(sender: Base, options: any) => any, Base, any>

Implemented in:

Base

An event that is raised when a property of this SurveyJS object has changed.

Parameters:

• sender: this
  A SurveyJS object whose property has changed.
• options.name: string
  The name of the changed property.
• options.newValue: any
  A new value for the property.
• options.oldValue: any
  An old value of the property. If the property is an array, oldValue contains the same array as newValue does.

If you need to add and remove property change event handlers dynamically, use the registerPropertyChangedHandlers and unregisterPropertyChangedHandlers methods instead.

Type:

EventBase<Base, any>

Implemented in:

Base

An event that is raised when the question's ready state has changed (expressions are evaluated, choices are loaded from a web resource specified by the choicesByUrl property, etc.).

Parameters:

• sender: SurveyModel
  A survey instance that contains the question whose ready state has changed.
• options.isReady: boolean
  Indicates whether the question is ready.
• options.oldIsReady: boolean
  Indicates the previous ready state.

Type:

EventBase<Question, any>

Implemented in:

Question

Returns a page to which the question belongs and allows you to move this question to a different page.

Type:

IPage writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

Returns a survey element (panel or page) that contains the question and allows you to move this question to a different survey element.

Type:

IPanel writable

Implemented in:

Question

A Dynamic Panel, Dynamic Matrix, or Dropdown Matrix that includes the current question.

This property is null for standalone questions.

Type:

E readonly

Implemented in:

SurveyElement

The number of quiz questions. A question counts if it is visible, has an input field, and specifies correctAnswer.

Type:

number readonly

Implemented in:

Question

See also:

Create a Quiz , correctAnswer * , SurveyModel.getQuizQuestions

Makes the survey element read-only.

If you want to switch a survey element to the read-only state based on a condition, specify the enableIf property. Refer to the following help topic for information: Conditional Visibility.

Type:

boolean writable

Implemented in:

SurveyElement

See also:

isReadOnly

Registers a single value change handler for one or multiple properties.

The registerPropertyChangedHandlers and unregisterPropertyChangedHandlers methods allow you to manage property change event handlers dynamically. If you only need to attach an event handler without removing it afterwards, you can use the onPropertyChanged event instead.

Type:

(propertyNames: string[], handler: any, key?: string) => void

Parameters:

propertyNames, type: string[] ,

An array of one or multiple property names.

handler, type: any ,

A function to call when one of the listed properties change. Accepts a new property value as an argument.

key, type: string ,

(Optional) A key that identifies the current registration. If a function for one of the properties is already registered with the same key, the function will be overwritten. You can also use the key to subsequently unregister handlers.

Implemented in:

Base

See also:

unregisterPropertyChangedHandlers

Returns the type of content that the Image question displays: "image", "video", or "youtube".

Type:

string readonly

Implemented in:

QuestionImageModel

See also:

contentMode

Returns a calculated width of the rendered survey element in CSS values.

Type:

string writable

Implemented in:

SurveyElement

See also:

width * , minWidth * , maxWidth

Specifies a custom error message for a required form field.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

isRequired

A Boolean expression. If it evaluates to true, this question becomes required.

A survey parses and runs all expressions on startup. If any values used in the expression change, the survey re-evaluates it.

Refer to the following help topic for more information: Conditional Visibility.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

isRequired

Returns a character or text string that indicates a required question.

Type:

string readonly

Implemented in:

Question

See also:

SurveyModel.requiredText * , isRequired

A Boolean expression. If it evaluates to true, the question value is reset to default.

A survey parses and runs all expressions on startup. If any values used in the expression change, the survey re-evaluates it.

View Demo

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

setValueIf

Increases or decreases an indent of survey element content from the right edge. Accepts positive integer values and 0. Does not apply in the Default V2 theme.

Type:

number writable

Implemented in:

SurveyElement

See also:

indent

Assigns a new value to a specified property.

Type:

(name: string, val: any) => void

Parameters:

name, type: string ,

A property name.

val, type: any ,

A new value for the property.

Implemented in:

Base

An expression used to calculate the question value.

You can use setValueExpression as a standalone property or in conjunction with the setValueIf expression, in which case the calculated question value applies only when setValueIf evaluates to true.

View Demo

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

defaultValueExpression * , resetValueIf

A Boolean expression. If it evaluates to true, the question value is set to a value calculated using the setValueExpression.

A survey parses and runs all expressions on startup. If any values used in the expression change, the survey re-evaluates it.

View Demo

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

resetValueIf

Specifies whether to display a comment area. Incompatible with the showOtherItem property.

Type:

boolean writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

comment * , commentText * , showOtherItem

Specifies whether to display the "Other" choice item. Incompatible with the showCommentArea property.

Type:

boolean writable

Implemented in:

Question

See also:

otherText * , otherItem * , otherErrorText * , showCommentArea * , settings.specialChoicesOrder

Disable this property if you want to render the current question on the same line or row with the previous question or panel.

Type:

boolean writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

True

Implemented in:

Question

Gets and sets the survey element's expand state.

Possible values:

• "default" (default) - The survey element is displayed in full and cannot be collapsed in the UI.
• "expanded" - The survey element is displayed in full and can be collapsed in the UI.
• "collapsed" - The survey element displays only title and description and can be expanded in the UI.

Type:

string writable

Implemented in:

SurveyElement

See also:

toggleState * , collapse * , expand * , isCollapsed * , isExpanded

Returns the survey object.

Type:

ISurvey readonly

Implemented in:

SurveyElement

A title for the survey element. If title is undefined, the name property value is displayed instead.

Empty pages and panels do not display their titles or names.

Type:

string writable

Implemented in:

SurveyElementCore

See also:

Configure Question Titles

Sets question title location relative to the input field. Overrides the questionTitleLocation property specified for the question's container (survey, page, or panel).

Possible values:

• "default" (default) - Inherits the setting from the questionTitleLocation property specified for the question's container.
• "top" - Displays the title above the input field.
• "bottom" - Displays the title below the input field.
• "left" - Displays the title to the left of the input field.
• "hidden" - Hides the question title.

Certain question types (Matrix, Multiple Text) do not support the "left" value. For them, the "top" value is used.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

default

Accepted values:

default , top , bottom , left , hidden

Implemented in:

Question

See also:

SurveyModel.questionTitleLocation * , getTitleLocation * , isAllowTitleLeft

Toggles the survey element's state between collapsed and expanded.

Type:

() => boolean

Implemented in:

SurveyElement

See also:

state * , collapse * , expand * , isCollapsed * , isExpanded

Returns a JSON object that corresponds to the current SurveyJS object.

Type:

(options?: ISaveToJSONOptions) => any

Parameters:

options, type: ISaveToJSONOptions

Implemented in:

Base

See also:

fromJSON

Unregisters value change event handlers for the specified properties.

Type:

(propertyNames: string[], key?: string) => void

Parameters:

propertyNames, type: string[] ,

An array of one or multiple property names.

key, type: string ,

(Optional) A key of the registration that you want to cancel.

Implemented in:

Base

See also:

registerPropertyChangedHandlers

Specifies whether to use display names for question values in placeholders.

Default value: true

This property applies to questions whose values are defined as objects with the value and text properties (for example, choice items in Radiogroup, Checkbox, and Dropdown questions).

You can use question values as placeholders in the following places:

• Survey element titles and descriptions
• The html property of the HTML question

To use a question value as a placeholder, specify the question name in curly brackets: {questionName}. Refer to the following help topic for more information: Dynamic Texts - Question Values.

Type:

boolean writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

True

Implemented in:

Question

Validates this question and returns false if the validation fails.

Type:

(fireCallback?: boolean, rec?: any) => boolean

Parameters:

fireCallback, type: boolean ,

(Optional) Pass false if you do not want to show validation errors in the UI.

rec, type: any

Implemented in:

Question

See also:

Data Validation

Question validators.

Data Validation

Type:

SurveyValidator[] writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

Gets or sets the question value.

The following table illustrates how the value type depends on the question type:

Type:

any writable

Implemented in:

Question

Specifies an object property that should store the question value.

Refer to the Merge Question Values help topic for more information.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

Gets or sets question visibility.

If you want to display or hide a question based on a condition, specify the visibleIf property. Refer to the following help topic for information: Conditional Visibility.

Type:

boolean writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Default value:

True

Implemented in:

Question

See also:

isVisible * , visibleIf

A Boolean expression. If it evaluates to false, this question becomes hidden.

A survey parses and runs all expressions on startup. If any values used in the expression change, the survey re-evaluates it.

Refer to the following help topic for more information: Conditional Visibility.

Type:

string writable

This property is stored in the survey JSON definition and can be edited in the Survey Creator.

Implemented in:

Question

See also:

visible * , isVisible

Returns the visible index of the question in the survey. It can be from 0 to all visible questions count - 1 The visibleIndex is -1 if the title is 'hidden' or hideNumber is true

Type:

number readonly

Implemented in:

Question

See also:

titleLocation * , hideNumber

Sets survey element width in CSS values.

Default value: ""

Type:

string writable

Implemented in:

SurveyElement

See also:

minWidth * , maxWidth