Abstract Class: Field<T>

Defined in: packages/blockly/core/field.ts:69

Abstract class for an editable field.

Extended by

Type Parameters

Type Parameter	Default type	Description
`T`	`any`	The value stored on the field.

Implements

Properties index

Property	Description
DEFAULT_VALUE	To overwrite the default value which is set in Field, directly update the prototype.
NBSP	Non-breaking space.
SKIP_SETUP	A value used to signal when a field's constructor should not set the field's value or run configure_, and should allow a subclass to do that instead.
name	Name of field. Unique within each block. Static labels are usually unnamed.
value_	-
validator_	Validation function called when user edits an editable field.
ariaTypeName	The ARIA-friendly label representation of this field's type.
fieldGroup_	The rendered field's SVG group element.
borderRect_	The rendered field's SVG border element.
textElement_	The rendered field's SVG text element.
textContent_	The rendered field's text content element.
constants_	Constants associated with the source block's renderer.
maxDisplayLength	Maximum characters of text to display before adding an ellipsis.
sourceBlock_	Block this field is attached to. Starts as null, then set in init.
isDirty_	Does this block need to be re-rendered?
visible_	Is the field visible, or hidden due to the block being collapsed?
enabled_	Can the field value be changed using the editor on an editable block?
clickTarget_	The element the click handler is bound to.
EDITABLE	Editable fields usually show some sort of UI indicating they are editable. They will also be saved by the serializer.
SERIALIZABLE	Serializable fields are saved by the serializer, non-serializable fields are not. Editable fields should also be serializable. This is not the case by default so that SERIALIZABLE is backwards compatible.

Methods index

Method	Description
configure_	Process the configuration map passed to the field.
setSourceBlock	Attach this field to a block.
getConstants	Get the renderer constant provider.
getSourceBlock	Get the block this field is attached to.
getAriaTypeName	Gets an ARIA-friendly label representation of this field's type.
setAriaTypeName	Sets the ARIA-friendly label representation of this field's type.
getAriaValue	Gets an ARIA-friendly label representation of this field's value.
computeAriaLabel	Computes a descriptive ARIA label to represent this field with configurable verbosity.
initView	Create the block UI for this field.
initModel	Initializes the model of the field after it has been installed on a block. No-op by default.
isFullBlockField	Defines whether this field should take up the full block or not.
createBorderRect_	Create a field border rect element. Not to be overridden by subclasses. Instead modify the result of the function inside initView, or create a separate function to call.
createTextElement_	Create a field text element. Not to be overridden by subclasses. Instead, modify the result of the function inside initView, or create a separate function to call. Aria state is hidden; use the aria label for the field and/or containing block to expose content to screen readers. Text content for custom blocks can be set after creation.
bindEvents_	Bind events to the field. Can be overridden by subclasses if they need to do custom input handling.
fromXml	Sets the field's value based on the given XML element. Should only be called by Blockly.Xml.
toXml	Serializes this field's value to XML. Should only be called by Blockly.Xml.
saveState	Saves this fields value as something which can be serialized to JSON. Should only be called by the serialization system.
loadState	Sets the field's state based on the given state value. Should only be called by the serialization system.
saveLegacyState	Returns a stringified version of the XML state, if it should be used. Otherwise this returns null, to signal the field should use its own serialization.
loadLegacyState	Loads the given state using either the old XML hooks, if they should be used. Returns true to indicate loading has been handled, false otherwise.
dispose	Dispose of all DOM objects and events belonging to this editable field.
updateEditable	Add or remove the UI indicating if this field is editable or not.
setEnabled	Set whether this field's value can be changed using the editor when the source block is editable.
isEnabled	Check whether this field's value can be changed using the editor when the source block is editable.
isClickable	Check whether this field defines the showEditor_ function.
isClickableInFlyout	Check whether the field should be clickable while the block is in a flyout. The default is that fields are clickable in always-open flyouts such as the simple toolbox, but not in autoclosing flyouts such as the category toolbox. Subclasses may override this function to change this behavior. Note that `isClickable` must also return true for this to have any effect.
isCurrentlyEditable	Check whether this field is currently editable. Some fields are never EDITABLE (e.g. text labels). Other fields may be EDITABLE but may exist on non-editable blocks or be currently disabled.
isSerializable	Check whether this field should be serialized by the XML renderer. Handles the logic for backwards compatibility and incongruous states.
isVisible	Gets whether this editable field is visible or not.
setValidator	Sets a new validation function for editable fields, or clears a previously set validator.
getValidator	Gets the validation function for editable fields, or null if not set.
getSvgRoot	Gets the group element for this editable field. Used for measuring the size and for positioning.
getBorderRect	Gets the border rectangle element.
getTextElement	Gets the text element.
getTextContent	Gets the text content.
applyColour	Updates the field to match the colour/style of the block.
render_	Used by getSize() to move/resize any DOM elements, and get the new size.
showEditor_	A developer hook to create an editor for the field. This is no-op by default, and must be overriden to create an editor.
repositionForWindowResize	A developer hook to reposition the WidgetDiv during a window resize. You need to define this hook if your field has a WidgetDiv that needs to reposition itself when the window is resized. For example, text input fields define this hook so that the input WidgetDiv can reposition itself on a window resize event. This is especially important when modal inputs have been disabled, as Android devices will fire a window resize event when the soft keyboard opens.
updateSize_	Updates the size of the field based on the text.
positionTextElement_	Position a field's text element after a size change. This handles both LTR and RTL positioning.
positionBorderRect_	Position a field's border rect after a size change.
getSize	Returns the height and width of the field.
onLocationChange	Notifies the field that it has changed locations.
getDisplayText_	Get the text from this field to display on the block. May differ from `getText` due to ellipsis, and other formatting.
getText	Get the text from this field. Override getText_ to provide a different behavior than simply casting the value to a string.
getText_	A developer hook to override the returned text of this field. Override if the text representation of the value of this field is not just a string cast of its value. Return null to resort to a string cast.
forceRerender	Force a rerender of the block that this field is installed on, which will rerender this field and adjust for any sizing changes. Other fields on the same block will not rerender, because their sizes have already been recorded.
setValue	Used to change the value of the field. Handles validation and events. Subclasses should override doClassValidation_ and doValueUpdate_ rather than this method.
getValue	Get the current value of the field.
doClassValidation_	Validate the changes to a field's value before they are set. See FieldDropdown for an example of subclass implementation.
doValueUpdate_	Used to update the value of a field. Can be overridden by subclasses to do custom storage of values/updating of external things.
doValueInvalid_	Used to notify the field an invalid value was input. Can be overridden by subclasses, see FieldTextInput. No-op by default.
onMouseDown_	Handle a pointerdown event on a field.
setTooltip	Sets the tooltip for this field.
getTooltip	Returns the tooltip text for this field.
getClickTarget_	The element to bind the click handler to. If not set explicitly, defaults to the SVG root of the field. When this element is clicked on an editable field, the editor will open.
getAbsoluteXY_	Return the absolute coordinates of the top-left corner of this field. The origin (0,0) is the top-left corner of the page body.
referencesVariables	Whether this field references any Blockly variables. If true it may need to be handled differently during serialization and deserialization. Subclasses may override this.
refreshVariableName	Refresh the variable name referenced by this field if this field references variables.
getFlipRtl	Returns whether or not we should flip the field in RTL.
onShortcut	Handles the given keyboard shortcut.
getFocusableElement	See IFocusableNode.getFocusableElement.
getFocusableTree	See IFocusableNode.getFocusableTree.
onNodeFocus	See IFocusableNode.onNodeFocus.
onNodeBlur	See IFocusableNode.onNodeBlur.
canBeFocused	See IFocusableNode.canBeFocused.
performAction	Handles the user acting on this field via keyboard navigation. Shows and focuses the field editor.
recomputeAriaContext	Recomputes the aria state and label for this field. Fields are generally hidden when in blocks in the flyout (except for top-level full-block fields), and otherwise set to a role of button (indicating they can be clicked to edit) and given the label returned from their `computeAriaLabel` method.
fromJson	Subclasses should reimplement this method to construct their Field subclass from a JSON arg object.

Constructors

Constructor

new Field<T>(
   value, 
   validator?, 
   config?
): Field<T>;

Defined in: packages/blockly/core/field.ts:216

Parameters

Parameter	Type	Description
`value`	`T` \| typeof `SKIP_SETUP`	The initial value of the field. Also accepts Field.SKIP_SETUP if you wish to skip setup (only used by subclasses that want to handle configuration and setting the field value after their own constructors have run).
`validator?`	`FieldValidator`<`T`> \| `null`	A function that is called to validate changes to the field's value. Takes in a value & returns a validated value, or null to abort the change.
`config?`	`FieldConfig`	A map of options used to configure the field. Refer to the individual field's documentation for a list of properties this parameter supports.

Returns

Field<T>

Properties

DEFAULT_VALUE

DEFAULT_VALUE: T | null = null;

Defined in: packages/blockly/core/field.ts:79

To overwrite the default value which is set in Field, directly update the prototype.

Example: FieldImage.prototype.DEFAULT_VALUE = null;

NBSP

readonly static NBSP: " " = '\u00A0';

Defined in: packages/blockly/core/field.ts:82

Non-breaking space.

SKIP_SETUP

readonly static SKIP_SETUP: typeof SKIP_SETUP;

Defined in: packages/blockly/core/field.ts:89

A value used to signal when a field's constructor should not set the field's value or run configure_, and should allow a subclass to do that instead.

name?

optional name?: string = undefined;

Defined in: packages/blockly/core/field.ts:95

Name of field. Unique within each block. Static labels are usually unnamed.

value_

protected value_: T | null;

Defined in: packages/blockly/core/field.ts:96

validator_

protected validator_: FieldValidator<T> | null = null;

Defined in: packages/blockly/core/field.ts:99

Validation function called when user edits an editable field.

ariaTypeName

protected ariaTypeName: string | null = null;

Defined in: packages/blockly/core/field.ts:102

The ARIA-friendly label representation of this field's type.

fieldGroup_

protected fieldGroup_: SVGGElement | null = null;

Defined in: packages/blockly/core/field.ts:130

The rendered field's SVG group element.

borderRect_

protected borderRect_: SVGRectElement | null = null;

Defined in: packages/blockly/core/field.ts:133

The rendered field's SVG border element.

textElement_

protected textElement_: SVGTextElement | null = null;

Defined in: packages/blockly/core/field.ts:136

The rendered field's SVG text element.

textContent_

protected textContent_: Text | null = null;

Defined in: packages/blockly/core/field.ts:139

The rendered field's text content element.

constants_

protected constants_: 
  | ConstantProvider
  | null = null;

Defined in: packages/blockly/core/field.ts:145

Constants associated with the source block's renderer.

maxDisplayLength

maxDisplayLength: number = 50;

Defined in: packages/blockly/core/field.ts:155

Maximum characters of text to display before adding an ellipsis.

sourceBlock_

protected sourceBlock_: Block | null = null;

Defined in: packages/blockly/core/field.ts:158

Block this field is attached to. Starts as null, then set in init.

isDirty_

protected isDirty_: boolean = true;

Defined in: packages/blockly/core/field.ts:161

Does this block need to be re-rendered?

visible_

protected visible_: boolean = true;

Defined in: packages/blockly/core/field.ts:164

Is the field visible, or hidden due to the block being collapsed?

enabled_

protected enabled_: boolean = true;

Defined in: packages/blockly/core/field.ts:169

Can the field value be changed using the editor on an editable block?

clickTarget_

protected clickTarget_: Element | null = null;

Defined in: packages/blockly/core/field.ts:172

The element the click handler is bound to.

EDITABLE

EDITABLE: boolean = true;

Defined in: packages/blockly/core/field.ts:192

Editable fields usually show some sort of UI indicating they are editable. They will also be saved by the serializer.

SERIALIZABLE

SERIALIZABLE: boolean = false;

Defined in: packages/blockly/core/field.ts:199

Serializable fields are saved by the serializer, non-serializable fields are not. Editable fields should also be serializable. This is not the case by default so that SERIALIZABLE is backwards compatible.

Accessors

size_

Get Signature

get protected size_(): Size;

Defined in: packages/blockly/core/field.ts:121

Gets the size of this field. Because getSize() and updateSize() have side effects, this acts as a shim for subclasses which wish to adjust field bounds when setting/getting the size without triggering unwanted rendering or other side effects. Note that subclasses must override both get and set if either is overridden; the implementation may just call directly through to super, but it must exist per the JS spec.

Returns

Size

Set Signature

set protected size_(newValue): void;

Defined in: packages/blockly/core/field.ts:125

Parameters

Parameter	Type
`newValue`	`Size`

Returns

void

Methods

configure_()

protected configure_(config): void;

Defined in: packages/blockly/core/field.ts:250

Process the configuration map passed to the field.

Parameters

Parameter	Type	Description
`config`	`FieldConfig`	A map of options used to configure the field. See the individual field's documentation for a list of properties this parameter supports.

Returns

void

setSourceBlock()

setSourceBlock(block): void;

Defined in: packages/blockly/core/field.ts:266

Attach this field to a block.

Parameters

Parameter	Type	Description
`block`	`Block`	The block containing this field.

Returns

void

getConstants()

getConstants(): 
  | ConstantProvider
  | null;

Defined in: packages/blockly/core/field.ts:284

Get the renderer constant provider.

Returns

| ConstantProvider | null

The renderer constant provider.

getSourceBlock()

getSourceBlock(): Block | null;

Defined in: packages/blockly/core/field.ts:304

Get the block this field is attached to.

Returns

Block | null

The block containing this field.

Throws

An error if the source block is not defined.

getAriaTypeName()

getAriaTypeName(): string | null;

Defined in: packages/blockly/core/field.ts:317

Gets an ARIA-friendly label representation of this field's type.

Implementations are responsible for, and encouraged to, return a localized version of the ARIA representation of the field's type.

Returns

string | null

An ARIA representation of the field's type or null if it is unspecified.

setAriaTypeName()

setAriaTypeName(ariaTypeName): void;

Defined in: packages/blockly/core/field.ts:332

Sets the ARIA-friendly label representation of this field's type.

Implementations are responsible for, and encouraged to, set a localized version of the ARIA representation of the field's type. To that end, the provided value may contain message references of the form %{BKY_...} (e.g. %{BKY_MY_FIELD_ARIA_TYPE}), which are replaced with the corresponding Blockly.Msg value.

Parameters

Parameter	Type	Description
`ariaTypeName`	`string`	An ARIA representation of the field's type.

Returns

void

getAriaValue()

getAriaValue(): string | null;

Defined in: packages/blockly/core/field.ts:355

Gets an ARIA-friendly label representation of this field's value.

Note that implementations should generally always override this value to ensure a non-null value is returned. The default implementation relies on 'getText' which may return an empty string. A null return value from this function will prompt ARIA label generation to skip the field's value entirely when there may be a better contextual placeholder to use isstead.

For example, to avoid hiding an empty text input field from screen reader, implementations should ensure that if the text is an empty string, this function would return an appropriate, localized value such as "empty text".

Implementations are responsible for, and encouraged to, return a localized version of the ARIA representation of the field's value.

Returns

string | null

An ARIA representation of the field's text, or null if no text is currently defined or known for the field.

computeAriaLabel()

computeAriaLabel(includeTypeInfo?): string;

Defined in: packages/blockly/core/field.ts:391

Computes a descriptive ARIA label to represent this field with configurable verbosity.

A 'verbose' label includes type information, if available, whereas a non-verbose label only contains the field's value.

Note that this will always return the latest representation of the field's label which may differ from any previously set ARIA label for the field itself. Implementations are largely responsible for ensuring that the field's ARIA label is set correctly at relevant moments in the field's lifecycle (such as when its value changes).

Finally, it is never guaranteed that implementations use the label returned by this method for their actual ARIA label. Some implementations may rely on other contexts to convey information like the field's value. Example: checkboxes represent their checked/non-checked status (i.e. value) through a separate ARIA property.

If the field's value is empty then it will return a localized placeholder indicating that its value is empty. If this method returns an empty string, the output will be ignored when composing the block-level ARIA label. Make sure you want your label hidden from screenreaders before returning an empty string.

Parameters

Parameter	Type	Default value	Description
`includeTypeInfo`	`boolean`	`true`	Whether to include the field's type information in the returned label, if available.

Returns

string

initView()

protected initView(): void;

Defined in: packages/blockly/core/field.ts:442

Create the block UI for this field.

Returns

void

initModel()

initModel(): void;

Defined in: packages/blockly/core/field.ts:454

Initializes the model of the field after it has been installed on a block. No-op by default.

Returns

void

isFullBlockField()

isFullBlockField(): boolean;

Defined in: packages/blockly/core/field.ts:470

Defines whether this field should take up the full block or not.

This is typically only done for certain kinds of fields and in certain renderers. You should only override this if you're sure your field will render correctly in zelos and other renderers that support full-block fields.

Blocks that contain only a single field that is a full-block-field have a special appearance in some renderers and their behavior is unique, because we pretend that the field is a whole block in some cases. This is hacky and you should use caution when attempting to do anything with this method.

Returns

boolean

createBorderRect_()

protected createBorderRect_(): void;

Defined in: packages/blockly/core/field.ts:489

Create a field border rect element. Not to be overridden by subclasses. Instead modify the result of the function inside initView, or create a separate function to call.

Returns

void

createTextElement_()

protected createTextElement_(): void;

Defined in: packages/blockly/core/field.ts:512

Create a field text element. Not to be overridden by subclasses. Instead, modify the result of the function inside initView, or create a separate function to call. Aria state is hidden; use the aria label for the field and/or containing block to expose content to screen readers. Text content for custom blocks can be set after creation.

Returns

void

bindEvents_()

protected bindEvents_(): void;

Defined in: packages/blockly/core/field.ts:532

Bind events to the field. Can be overridden by subclasses if they need to do custom input handling.

Returns

void

fromXml()

fromXml(fieldElement): void;

Defined in: packages/blockly/core/field.ts:550

Sets the field's value based on the given XML element. Should only be called by Blockly.Xml.

Parameters

Parameter	Type	Description
`fieldElement`	`Element`	The element containing info about the field's state.

Returns

void

toXml()

toXml(fieldElement): Element;

Defined in: packages/blockly/core/field.ts:562

Serializes this field's value to XML. Should only be called by Blockly.Xml.

Parameters

Parameter	Type	Description
`fieldElement`	`Element`	The element to populate with info about the field's state.

Returns

Element

The element containing info about the field's state.

saveState()

saveState(_doFullSerialization?): any;

Defined in: packages/blockly/core/field.ts:580

Saves this fields value as something which can be serialized to JSON. Should only be called by the serialization system.

Parameters

Parameter	Type	Description
`_doFullSerialization?`	`boolean`	If true, this signals to the field that if it normally just saves a reference to some state (eg variable fields) it should instead serialize the full state of the thing being referenced. See the field serialization docs for more information.

Returns

any

JSON serializable state.

Implementation of

ISerializable.saveState

loadState()

loadState(state): void;

Defined in: packages/blockly/core/field.ts:594

Sets the field's state based on the given state value. Should only be called by the serialization system.

Parameters

Parameter	Type	Description
`state`	`any`	The state we want to apply to the field.

Returns

void

Implementation of

ISerializable.loadState

saveLegacyState()

protected saveLegacyState(callingClass): string | null;

Defined in: packages/blockly/core/field.ts:610

Returns a stringified version of the XML state, if it should be used. Otherwise this returns null, to signal the field should use its own serialization.

Parameters

Parameter	Type	Description
`callingClass`	`FieldProto`	The class calling this method. Used to see if `this` has overridden any relevant hooks.

Returns

string | null

The stringified version of the XML state, or null.

loadLegacyState()

loadLegacyState(callingClass, state): boolean;

Defined in: packages/blockly/core/field.ts:637

Loads the given state using either the old XML hooks, if they should be used. Returns true to indicate loading has been handled, false otherwise.

Parameters

Parameter	Type	Description
`callingClass`	`FieldProto`	The class calling this method. Used to see if `this` has overridden any relevant hooks.
`state`	`any`	The state to apply to the field.

Returns

boolean

Whether the state was applied or not.

dispose()

dispose(): void;

Defined in: packages/blockly/core/field.ts:656

Dispose of all DOM objects and events belonging to this editable field.

Returns

void

updateEditable()

updateEditable(): void;

Defined in: packages/blockly/core/field.ts:675

Add or remove the UI indicating if this field is editable or not.

Returns

void

setEnabled()

setEnabled(enabled): void;

Defined in: packages/blockly/core/field.ts:696

Set whether this field's value can be changed using the editor when the source block is editable.

Parameters

Parameter	Type	Description
`enabled`	`boolean`	True if enabled.

Returns

void

isEnabled()

isEnabled(): boolean;

Defined in: packages/blockly/core/field.ts:707

Check whether this field's value can be changed using the editor when the source block is editable.

Returns

boolean

Whether this field is enabled.

isClickable()

isClickable(): boolean;

Defined in: packages/blockly/core/field.ts:716

Check whether this field defines the showEditor_ function.

Returns

boolean

Whether this field is clickable.

isClickableInFlyout()

isClickableInFlyout(autoClosingFlyout): boolean;

Defined in: packages/blockly/core/field.ts:735

Check whether the field should be clickable while the block is in a flyout. The default is that fields are clickable in always-open flyouts such as the simple toolbox, but not in autoclosing flyouts such as the category toolbox. Subclasses may override this function to change this behavior. Note that isClickable must also return true for this to have any effect.

Parameters

Parameter	Type	Description
`autoClosingFlyout`	`boolean`	true if the containing flyout is an auto-closing one.

Returns

boolean

Whether the field should be clickable while the block is in a flyout.

isCurrentlyEditable()

isCurrentlyEditable(): boolean;

Defined in: packages/blockly/core/field.ts:747

Check whether this field is currently editable. Some fields are never EDITABLE (e.g. text labels). Other fields may be EDITABLE but may exist on non-editable blocks or be currently disabled.

Returns

boolean

Whether this field is currently enabled, editable and on an editable block.

isSerializable()

isSerializable(): boolean;

Defined in: packages/blockly/core/field.ts:762

Check whether this field should be serialized by the XML renderer. Handles the logic for backwards compatibility and incongruous states.

Returns

boolean

Whether this field should be serialized or not.

isVisible()

isVisible(): boolean;

Defined in: packages/blockly/core/field.ts:784

Gets whether this editable field is visible or not.

Returns

boolean

True if visible.

setValidator()

setValidator(handler): void;

Defined in: packages/blockly/core/field.ts:821

Sets a new validation function for editable fields, or clears a previously set validator.

The validator function takes in the new field value, and returns validated value. The validated value could be the input value, a modified version of the input value, or null to abort the change.

If the function does not return anything (or returns undefined) the new value is accepted as valid. This is to allow for fields using the validated function as a field-level change event notification.

Parameters

Parameter	Type	Description
`handler`	`FieldValidator`<`T`>	The validator function or null to clear a previous validator.

Returns

void

getValidator()

getValidator(): FieldValidator<T> | null;

Defined in: packages/blockly/core/field.ts:830

Gets the validation function for editable fields, or null if not set.

Returns

FieldValidator<T> | null

Validation function, or null.

getSvgRoot()

getSvgRoot(): SVGGElement | null;

Defined in: packages/blockly/core/field.ts:840

Gets the group element for this editable field. Used for measuring the size and for positioning.

Returns

SVGGElement | null

The group element.

getBorderRect()

protected getBorderRect(): SVGRectElement;

Defined in: packages/blockly/core/field.ts:850

Gets the border rectangle element.

Returns

SVGRectElement

The border rectangle element.

Throws

An error if the border rectangle element is not defined.

getTextElement()

protected getTextElement(): SVGTextElement;

Defined in: packages/blockly/core/field.ts:863

Gets the text element.

Returns

SVGTextElement

The text element.

Throws

An error if the text element is not defined.

getTextContent()

protected getTextContent(): Text;

Defined in: packages/blockly/core/field.ts:876

Gets the text content.

Returns

Text

The text content.

Throws

An error if the text content is not defined.

applyColour()

applyColour(): void;

Defined in: packages/blockly/core/field.ts:895

Updates the field to match the colour/style of the block.

Non-abstract sub-classes may wish to implement this if the colour of the field depends on the colour of the block. It will automatically be called at relevant times, such as when the parent block or renderer changes.

See the field documentation for more information, or FieldDropdown for an example.

Returns

void

render_()

protected render_(): void;

Defined in: packages/blockly/core/field.ts:903

Used by getSize() to move/resize any DOM elements, and get the new size.

All rendering that has an effect on the size/shape of the block should be done here, and should be triggered by getSize().

Returns

void

showEditor_()

protected showEditor_(_e?): void;

Defined in: packages/blockly/core/field.ts:932

A developer hook to create an editor for the field. This is no-op by default, and must be overriden to create an editor.

Parameters

Parameter	Type	Description
`_e?`	`Event`	Optional mouse event that triggered the field to open, or undefined if triggered programmatically.

Returns

void

repositionForWindowResize()

repositionForWindowResize(): boolean;

Defined in: packages/blockly/core/field.ts:953

A developer hook to reposition the WidgetDiv during a window resize. You need to define this hook if your field has a WidgetDiv that needs to reposition itself when the window is resized. For example, text input fields define this hook so that the input WidgetDiv can reposition itself on a window resize event. This is especially important when modal inputs have been disabled, as Android devices will fire a window resize event when the soft keyboard opens.

If you want the WidgetDiv to hide itself instead of repositioning, return false. This is the default behavior.

DropdownDivs already handle their own positioning logic, so you do not need to override this function if your field only has a DropdownDiv.

Returns

boolean

True if the field should be repositioned, false if the WidgetDiv should hide itself instead.

updateSize_()

protected updateSize_(margin?): void;

Defined in: packages/blockly/core/field.ts:962

Updates the size of the field based on the text.

Parameters

Parameter	Type	Description
`margin?`	`number`	margin to use when positioning the text element.

Returns

void

positionTextElement_()

protected positionTextElement_(xOffset, contentWidth): void;

Defined in: packages/blockly/core/field.ts:995

Position a field's text element after a size change. This handles both LTR and RTL positioning.

Parameters

Parameter	Type	Description
`xOffset`	`number`	x offset to use when positioning the text element.
`contentWidth`	`number`	The content width.

Returns

void

positionBorderRect_()

protected positionBorderRect_(): void;

Defined in: packages/blockly/core/field.ts:1023

Position a field's border rect after a size change.

Returns

void

getSize()

getSize(): Size;

Defined in: packages/blockly/core/field.ts:1046

Returns the height and width of the field.

This should in general be the only place render_ gets called from.

Returns

Size

Height and width.

onLocationChange()

onLocationChange(_): void;

Defined in: packages/blockly/core/field.ts:1107

Notifies the field that it has changed locations.

Parameters

Parameter	Type	Description
`_`	`Coordinate`	The location of this field's block's top-start corner in workspace coordinates.

Returns

void

getDisplayText_()

protected getDisplayText_(): string;

Defined in: packages/blockly/core/field.ts:1115

Get the text from this field to display on the block. May differ from getText due to ellipsis, and other formatting.

Returns

string

Text to display.

getText()

getText(): string;

Defined in: packages/blockly/core/field.ts:1138

Sealed

Get the text from this field. Override getText_ to provide a different behavior than simply casting the value to a string.

Returns

string

Current text.

getText_()

protected getText_(): string | null;

Defined in: packages/blockly/core/field.ts:1156

A developer hook to override the returned text of this field. Override if the text representation of the value of this field is not just a string cast of its value. Return null to resort to a string cast.

Returns

string | null

Current text or null.

forceRerender()

forceRerender(): void;

Defined in: packages/blockly/core/field.ts:1179

Force a rerender of the block that this field is installed on, which will rerender this field and adjust for any sizing changes. Other fields on the same block will not rerender, because their sizes have already been recorded.

Returns

void

setValue()

setValue(newValue, fireChangeEvent?): void;

Defined in: packages/blockly/core/field.ts:1197

Sealed

Used to change the value of the field. Handles validation and events. Subclasses should override doClassValidation_ and doValueUpdate_ rather than this method.

Parameters

Parameter	Type	Default value	Description
`newValue`	`any`	`undefined`	New value.
`fireChangeEvent`	`boolean`	`true`	Whether to fire a change event. Defaults to true. Should usually be true unless the change will be reported some other way, e.g. an intermediate field change event.

Returns

void

getValue()

getValue(): T | null;

Defined in: packages/blockly/core/field.ts:1297

Get the current value of the field.

Returns

T | null

Current value.

doClassValidation_()

Call Signature

protected doClassValidation_(newValue): T | null | undefined;

Defined in: packages/blockly/core/field.ts:1321

Validate the changes to a field's value before they are set. See FieldDropdown for an example of subclass implementation.

NOTE: Validation returns one option between T, null, and undefined. Field's implementation will never return undefined, but it is valid for a subclass to return undefined if the new value is compatible with T.

Parameters

Parameter	Type	Description
`newValue`	`T`	The value to be validated.

Returns

T | null | undefined

One of three instructions for setting the new value: T, null, or undefined.

T to set this function's returned value instead of newValue.
null to invoke doValueInvalid_ and not set a value.
undefined to set newValue as is.

See

https://docs.blockly.com/guides/create-custom-blocks/fields/validators/#return-values

Call Signature

protected doClassValidation_(newValue?): T | null;

Defined in: packages/blockly/core/field.ts:1322

Validate the changes to a field's value before they are set. See FieldDropdown for an example of subclass implementation.

Parameters

Parameter	Type	Description
`newValue?`	`any`	The value to be validated.

Returns

T | null

One of three instructions for setting the new value: T, null, or undefined.

T to set this function's returned value instead of newValue.
null to invoke doValueInvalid_ and not set a value.
undefined to set newValue as is.

See

https://docs.blockly.com/guides/create-custom-blocks/fields/validators/#return-values

doValueUpdate_()

protected doValueUpdate_(newValue): void;

Defined in: packages/blockly/core/field.ts:1339

Used to update the value of a field. Can be overridden by subclasses to do custom storage of values/updating of external things.

Parameters

Parameter	Type	Description
`newValue`	`T`	The value to be saved.

Returns

void

doValueInvalid_()

protected doValueInvalid_(_invalidValue, _fireChangeEvent?): void;

Defined in: packages/blockly/core/field.ts:1352

Used to notify the field an invalid value was input. Can be overridden by subclasses, see FieldTextInput. No-op by default.

Parameters

Parameter	Type	Default value	Description
`_invalidValue`	`any`	`undefined`	The input value that was determined to be invalid.
`_fireChangeEvent`	`boolean`	`true`	Whether to fire a change event if the value changes.

Returns

void

onMouseDown_()

protected onMouseDown_(e): void;

Defined in: packages/blockly/core/field.ts:1363

Handle a pointerdown event on a field.

Parameters

Parameter	Type	Description
`e`	`PointerEvent`	Pointer down event.

Returns

void

setTooltip()

setTooltip(newTip): void;

Defined in: packages/blockly/core/field.ts:1381

Sets the tooltip for this field.

Parameters

Parameter	Type	Description
`newTip`	`TipInfo` \| `null`	The text for the tooltip, a function that returns the text for the tooltip, a parent object whose tooltip will be used, or null to display the tooltip of the parent block. To not display a tooltip pass the empty string.

Returns

void

getTooltip()

getTooltip(): string;

Defined in: packages/blockly/core/field.ts:1400

Returns the tooltip text for this field.

Returns

string

The tooltip text for this field.

getClickTarget_()

protected getClickTarget_(): Element | null;

Defined in: packages/blockly/core/field.ts:1416

The element to bind the click handler to. If not set explicitly, defaults to the SVG root of the field. When this element is clicked on an editable field, the editor will open.

Returns

Element | null

Element to bind click handler to.

getAbsoluteXY_()

protected getAbsoluteXY_(): Coordinate;

Defined in: packages/blockly/core/field.ts:1426

Return the absolute coordinates of the top-left corner of this field. The origin (0,0) is the top-left corner of the page body.

Returns

Coordinate

Object with .x and .y properties.

referencesVariables()

referencesVariables(): boolean;

Defined in: packages/blockly/core/field.ts:1437

Whether this field references any Blockly variables. If true it may need to be handled differently during serialization and deserialization. Subclasses may override this.

Returns

boolean

True if this field has any variable references.

refreshVariableName()

refreshVariableName(): void;

Defined in: packages/blockly/core/field.ts:1445

Refresh the variable name referenced by this field if this field references variables.

Returns

void

getFlipRtl()

getFlipRtl(): boolean;

Defined in: packages/blockly/core/field.ts:1481

Returns whether or not we should flip the field in RTL.

Returns

boolean

True if we should flip in RTL.

onShortcut()

onShortcut(_shortcut): boolean;

Defined in: packages/blockly/core/field.ts:1491

Handles the given keyboard shortcut.

Parameters

Parameter	Type	Description
`_shortcut`	`KeyboardShortcut`	The shortcut to be handled.

Returns

boolean

True if the shortcut has been handled, false otherwise.

Implementation of

IKeyboardAccessible.onShortcut

getFocusableElement()

getFocusableElement(): HTMLElement | SVGElement;

Defined in: packages/blockly/core/field.ts:1496

See IFocusableNode.getFocusableElement.

Returns

HTMLElement | SVGElement

Implementation of

IFocusableNode.getFocusableElement

getFocusableTree()

getFocusableTree(): IFocusableTree;

Defined in: packages/blockly/core/field.ts:1504

See IFocusableNode.getFocusableTree.

Returns

IFocusableTree

Implementation of

IFocusableNode.getFocusableTree

onNodeFocus()

onNodeFocus(): void;

Defined in: packages/blockly/core/field.ts:1513

See IFocusableNode.onNodeFocus.

Returns

void

Implementation of

IFocusableNode.onNodeFocus

onNodeBlur()

onNodeBlur(): void;

Defined in: packages/blockly/core/field.ts:1521

See IFocusableNode.onNodeBlur.

Returns

void

Implementation of

IFocusableNode.onNodeBlur

canBeFocused()

canBeFocused(): boolean;

Defined in: packages/blockly/core/field.ts:1524

See IFocusableNode.canBeFocused.

Returns

boolean

Implementation of

IFocusableNode.canBeFocused

performAction()

performAction(): void;

Defined in: packages/blockly/core/field.ts:1532

Handles the user acting on this field via keyboard navigation. Shows and focuses the field editor.

Returns

void

Implementation of

IFocusableNode.performAction

recomputeAriaContext()

recomputeAriaContext(): boolean;

Defined in: packages/blockly/core/field.ts:1551

Recomputes the aria state and label for this field. Fields are generally hidden when in blocks in the flyout (except for top-level full-block fields), and otherwise set to a role of button (indicating they can be clicked to edit) and given the label returned from their computeAriaLabel method.

Subclasses can override this in order to change the role or label, but they must ensure they keep the correct behavior for fields in flyout blocks.

This method will return a boolean indicating if the element is displayed in the aria tree or not. This can be used by subclasses to determine whether or not to continue customizing the role and label (hidden elements should not have labels).

Returns

boolean

true if the element is in the accessibility tree, false if the aria state is hidden

fromJson()

static fromJson(_options): Field;

Defined in: packages/blockly/core/field.ts:1617

Subclasses should reimplement this method to construct their Field subclass from a JSON arg object.

It is an error to attempt to register a field subclass in the FieldRegistry if that subclass has not overridden this method.

Parameters

Parameter	Type	Description
`_options`	`FieldConfig`	JSON configuration object with properties needed to configure a specific field.

Returns

Field

Extended by​

Type Parameters​

Implements​

Properties index​

Methods index​

Constructors​

Constructor​

Parameters​

Returns​

Properties​

DEFAULT_VALUE​

NBSP​

SKIP_SETUP​

name?​

value_​

validator_​

ariaTypeName​

fieldGroup_​

borderRect_​

textElement_​

textContent_​

constants_​

maxDisplayLength​

sourceBlock_​

isDirty_​

visible_​

enabled_​

clickTarget_​

EDITABLE​

SERIALIZABLE​

Accessors​

size_​

Get Signature​

Returns​

Set Signature​

Parameters​

Returns​

Methods​

configure_()​

Parameters​

Returns​

setSourceBlock()​

Parameters​

Returns​

getConstants()​

Returns​

getSourceBlock()​

Returns​

Throws​

getAriaTypeName()​

Returns​

setAriaTypeName()​

Parameters​

Returns​

getAriaValue()​

Returns​

computeAriaLabel()​

Parameters​

Returns​

initView()​

Returns​

initModel()​

Returns​

isFullBlockField()​

Returns​

createBorderRect_()​

Returns​

createTextElement_()​

Returns​

bindEvents_()​

Returns​

fromXml()​

Parameters​

Returns​

toXml()​

Parameters​

Returns​

saveState()​

Parameters​

Returns​

Extended by

Type Parameters

Implements

Properties index

Methods index

Constructors

Constructor

Parameters

Returns

Properties

DEFAULT_VALUE

NBSP

SKIP_SETUP

name?

value_

validator_

ariaTypeName

fieldGroup_

borderRect_

textElement_

textContent_

constants_

maxDisplayLength

sourceBlock_

isDirty_

visible_

enabled_

clickTarget_

EDITABLE

SERIALIZABLE

Accessors

size_

Get Signature

Returns

Set Signature

Parameters

Returns

Methods

configure_()

Parameters

Returns

setSourceBlock()

Parameters

Returns

getConstants()

Returns

getSourceBlock()

Returns

Throws

getAriaTypeName()

Returns

setAriaTypeName()

Parameters

Returns

getAriaValue()

Returns

computeAriaLabel()

Parameters

Returns

initView()

Returns

initModel()

Returns

isFullBlockField()

Returns

createBorderRect_()

Returns

createTextElement_()

Returns

bindEvents_()

Returns

fromXml()

Parameters

Returns

toXml()

Parameters

Returns

saveState()

Parameters

Returns