Files
blockly/core/field_input.ts
Ben Henning d0ad9343f0 feat: Add initial support for screen readers (experimental) (#9280)
## The basics

- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)

## The details
### Resolves

Fixes part of #8207
Fixes part of #3370

### Proposed Changes

This introduces initial broad ARIA integration in order to enable at least basic screen reader support when using keyboard navigation.

Largely this involves introducing ARIA roles and labels in a bunch of places, sometimes done in a way to override normal built-in behaviors of the accessibility node tree in order to get a richer first-class output for Blockly (such as for blocks and workspaces).

### Reason for Changes

ARIA is the fundamental basis for configuring how focusable nodes in Blockly are represented to the user when using a screen reader. As such, all focusable nodes requires labels and roles in order to correctly communicate their contexts.

The specific approach taken in this PR is to simply add labels and roles to all nodes where obvious with some extra work done for `WorkspaceSvg` and `BlockSvg` in order to represent blocks as a tree (since that seems to be the best fitting ARIA role per those available: https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Reference/Roles). The custom work specifically for blocks includes:
- Overriding the role description to be 'block' rather than 'tree item' (which is the default).
- Overriding the position, level, and number of sibling counts since those are normally determined based on the DOM tree and blocks are not laid out in the tree the same way they are visually or logically (so these computations were incorrect). This is also the reason for a bunch of extra computation logic being introduced.

One note on some of the labels being nonsensical (e.g. 'DoNotOverride?'): this was done intentionally to try and ensure _all_ focusable nodes (that can be focused) have labels, even when the specifics of what that label should be aren't yet clear. More components had these temporary labels until testing revealed how exactly they would behave from a screen reader perspective (at which point their roles and labels were updated as needed). The temporary labels act as an indicator when navigating through the UI, and some of the nodes can't easily be reached (for reasons) and thus may never actually need a label. More work is needed in understanding both what components need labels and what those labels should be, but that will be done beyond this PR.

### Test Coverage

No tests are added to this as it's experimental and not a final implementation.

The keyboard navigation tests are failing due to a visibility expansion of `connectionCandidate` in `BlockDragStrategy`. There's no way to avoid this breakage, unfortunately. Instead, this PR will be merged and then https://github.com/google/blockly-keyboard-experimentation/pull/684 will be finalized and merged to fix it. There's some additional work that will happen both in that branch and in a later PR in core Blockly to integrate the two experimentation branches as part of #9283 so that CI passes correctly for both branches.

### Documentation

No documentation is needed at this time.

### Additional Information

This work is experimental and is meant to serve two purposes:
- Provide a foundation for testing and iterating the core screen reader experience in Blockly.
- Provide a reference point for designing a long-term solution that accounts for all requirements collected during user testing.

This code should never be merged into `develop` as it stands. Instead, it will be redesigned with maintainability, testing, and correctness in mind at a future date (see https://github.com/google/blockly-keyboard-experimentation/discussions/673).
2025-08-06 15:28:45 -07:00

815 lines
26 KiB
TypeScript

/**
* @license
* Copyright 2012 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* Text input field.
*
* @class
*/
// Former goog.module ID: Blockly.FieldInput
// Unused import preserved for side-effects. Remove if unneeded.
import './events/events_block_change.js';
import {BlockSvg} from './block_svg.js';
import * as browserEvents from './browser_events.js';
import * as bumpObjects from './bump_objects.js';
import * as dialog from './dialog.js';
import * as dropDownDiv from './dropdowndiv.js';
import {EventType} from './events/type.js';
import * as eventUtils from './events/utils.js';
import {
Field,
FieldConfig,
FieldValidator,
UnattachedFieldError,
} from './field.js';
import {getFocusManager} from './focus_manager.js';
import type {IFocusableNode} from './interfaces/i_focusable_node.js';
import {Msg} from './msg.js';
import * as renderManagement from './render_management.js';
import * as aria from './utils/aria.js';
import * as dom from './utils/dom.js';
import {Size} from './utils/size.js';
import * as userAgent from './utils/useragent.js';
import * as WidgetDiv from './widgetdiv.js';
import type {WorkspaceSvg} from './workspace_svg.js';
/**
* Supported types for FieldInput subclasses.
*
* @internal
*/
type InputTypes = string | number;
/**
* Abstract class for an editable input field.
*
* @typeParam T - The value stored on the field.
* @internal
*/
export abstract class FieldInput<T extends InputTypes> extends Field<
string | T
> {
/**
* Pixel size of input border radius.
* Should match blocklyText's border-radius in CSS.
*/
static BORDERRADIUS = 4;
/** Allow browser to spellcheck this field. */
protected spellcheck_ = true;
/** The HTML input element. */
protected htmlInput_: HTMLInputElement | null = null;
/** True if the field's value is currently being edited via the UI. */
protected isBeingEdited_ = false;
/**
* True if the value currently displayed in the field's editory UI is valid.
*/
protected isTextValid_ = false;
/**
* The intial value of the field when the user opened an editor to change its
* value. When the editor is disposed, an event will be fired that uses this
* as the event's oldValue.
*/
protected valueWhenEditorWasOpened_: string | T | null = null;
/** Key down event data. */
private onKeyDownWrapper: browserEvents.Data | null = null;
/** Input element input event data. */
private onInputWrapper: browserEvents.Data | null = null;
/**
* Whether the field should consider the whole parent block to be its click
* target.
*/
fullBlockClickTarget_: boolean = false;
/** The workspace that this field belongs to. */
protected workspace_: WorkspaceSvg | null = null;
/**
* Serializable fields are saved by the serializer, non-serializable fields
* are not. Editable fields should also be serializable.
*/
override SERIALIZABLE = true;
/**
* Sets the size of this field. Although this appears to be a no-op, it must
* exist since the getter is overridden below.
*/
protected override set size_(newValue: Size) {
super.size_ = newValue;
}
/**
* Returns the size of this field, with a minimum width of 14.
*/
protected override get size_() {
const s = super.size_;
if (s.width < 14) {
s.width = 14;
}
return s;
}
/**
* @param value The initial value of the field. Should cast to a string.
* Defaults to an empty string if null or undefined. 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).
* @param validator A function that is called to validate changes to the
* field's value. Takes in a string & returns a validated string, or null
* to abort the change.
* @param config A map of options used to configure the field.
* See the [field creation documentation]{@link
* https://developers.google.com/blockly/guides/create-custom-blocks/fields/built-in-fields/text-input#creation}
* for a list of properties this parameter supports.
*/
constructor(
value?: string | typeof Field.SKIP_SETUP,
validator?: FieldInputValidator<T> | null,
config?: FieldInputConfig,
) {
super(Field.SKIP_SETUP);
if (value === Field.SKIP_SETUP) return;
if (config) {
this.configure_(config);
}
this.setValue(value);
if (validator) {
this.setValidator(validator);
}
}
protected override configure_(config: FieldInputConfig) {
super.configure_(config);
if (config.spellcheck !== undefined) {
this.spellcheck_ = config.spellcheck;
}
}
override initView() {
const block = this.getSourceBlock();
if (!block) throw new UnattachedFieldError();
super.initView();
if (this.isFullBlockField()) {
this.clickTarget_ = (this.sourceBlock_ as BlockSvg).getSvgRoot();
}
if (this.fieldGroup_) {
dom.addClass(this.fieldGroup_, 'blocklyInputField');
}
const element = this.getFocusableElement();
aria.setRole(element, aria.Role.TEXTBOX);
aria.setState(
element,
aria.State.LABEL,
this.name ? `Text ${this.name}` : 'Text',
);
}
override isFullBlockField(): boolean {
const block = this.getSourceBlock();
if (!block) throw new UnattachedFieldError();
// Side effect for backwards compatibility.
this.fullBlockClickTarget_ =
!!this.getConstants()?.FULL_BLOCK_FIELDS && block.isSimpleReporter();
return this.fullBlockClickTarget_;
}
/**
* Called by setValue if the text input is not valid. If the field is
* currently being edited it reverts value of the field to the previous
* value while allowing the display text to be handled by the htmlInput_.
*
* @param _invalidValue The input value that was determined to be invalid.
* This is not used by the text input because its display value is stored
* on the htmlInput_.
* @param fireChangeEvent Whether to fire a change event if the value changes.
*/
protected override doValueInvalid_(
_invalidValue: AnyDuringMigration,
fireChangeEvent: boolean = true,
) {
if (this.isBeingEdited_) {
this.isDirty_ = true;
this.isTextValid_ = false;
const oldValue = this.value_;
// Revert value when the text becomes invalid.
this.value_ = this.valueWhenEditorWasOpened_;
if (
this.sourceBlock_ &&
eventUtils.isEnabled() &&
this.value_ !== oldValue &&
fireChangeEvent
) {
eventUtils.fire(
new (eventUtils.get(EventType.BLOCK_CHANGE))(
this.sourceBlock_,
'field',
this.name || null,
oldValue,
this.value_,
),
);
}
}
}
/**
* Called by setValue if the text input is valid. Updates the value of the
* field, and updates the text of the field if it is not currently being
* edited (i.e. handled by the htmlInput_).
*
* @param newValue The value to be saved. The default validator guarantees
* that this is a string.
*/
protected override doValueUpdate_(newValue: string | T) {
this.isDirty_ = true;
this.isTextValid_ = true;
this.value_ = newValue;
}
/**
* Updates text field to match the colour/style of the block.
*/
override applyColour() {
const block = this.getSourceBlock() as BlockSvg | null;
if (!block) throw new UnattachedFieldError();
if (!this.getConstants()!.FULL_BLOCK_FIELDS) return;
if (!this.fieldGroup_) return;
if (!this.isFullBlockField() && this.borderRect_) {
this.borderRect_!.style.display = 'block';
this.borderRect_.setAttribute('stroke', block.getColourTertiary());
} else {
this.borderRect_!.style.display = 'none';
// In general, do *not* let fields control the color of blocks. Having the
// field control the color is unexpected, and could have performance
// impacts.
block.pathObject.svgPath.setAttribute(
'fill',
this.getConstants()!.FIELD_BORDER_RECT_COLOUR,
);
}
}
/**
* Returns the height and width of the field.
*
* This should *in general* be the only place render_ gets called from.
*
* @returns Height and width.
*/
override getSize(): Size {
if (this.getConstants()?.FULL_BLOCK_FIELDS) {
// In general, do *not* let fields control the color of blocks. Having the
// field control the color is unexpected, and could have performance
// impacts.
// Full block fields have more control of the block than they should
// (i.e. updating fill colour). Whenever we get the size, the field may
// no longer be a full-block field, so we need to rerender.
this.render_();
this.isDirty_ = false;
}
return super.getSize();
}
/**
* Notifies the field that it has changed locations. Moves the widget div to
* be in the correct place if it is open.
*/
onLocationChange(): void {
if (this.isBeingEdited_) this.resizeEditor_();
}
/**
* Updates the colour of the htmlInput given the current validity of the
* field's value.
*
* Also updates the colour of the block to reflect whether this is a full
* block field or not.
*/
protected override render_() {
super.render_();
// This logic is done in render_ rather than doValueInvalid_ or
// doValueUpdate_ so that the code is more centralized.
if (this.isBeingEdited_) {
const htmlInput = this.htmlInput_ as HTMLElement;
if (!this.isTextValid_) {
dom.addClass(htmlInput, 'blocklyInvalidInput');
aria.setState(htmlInput, aria.State.INVALID, true);
} else {
dom.removeClass(htmlInput, 'blocklyInvalidInput');
aria.setState(htmlInput, aria.State.INVALID, false);
}
}
const block = this.getSourceBlock() as BlockSvg | null;
if (!block) throw new UnattachedFieldError();
// In general, do *not* let fields control the color of blocks. Having the
// field control the color is unexpected, and could have performance
// impacts.
// Whenever we render, the field may no longer be a full-block-field so
// we need to update the colour.
if (this.getConstants()!.FULL_BLOCK_FIELDS) block.applyColour();
}
/**
* Set whether this field is spellchecked by the browser.
*
* @param check True if checked.
*/
setSpellcheck(check: boolean) {
if (check === this.spellcheck_) {
return;
}
this.spellcheck_ = check;
if (this.htmlInput_) {
// AnyDuringMigration because: Argument of type 'boolean' is not
// assignable to parameter of type 'string'.
this.htmlInput_.setAttribute(
'spellcheck',
this.spellcheck_ as AnyDuringMigration,
);
}
}
/**
* Show an editor for the field.
* Shows the inline free-text editor on top of the text by default.
* Shows a prompt editor for mobile browsers if the modalInputs option is
* enabled.
*
* @param _e Optional mouse event that triggered the field to open, or
* undefined if triggered programmatically.
* @param quietInput True if editor should be created without focus.
* Defaults to false.
* @param manageEphemeralFocus Whether ephemeral focus should be managed as
* part of the editor's inline editor (when the inline editor is shown).
* Callers must manage ephemeral focus themselves if this is false.
* Defaults to true.
*/
protected override showEditor_(
_e?: Event,
quietInput = false,
manageEphemeralFocus: boolean = true,
) {
this.workspace_ = (this.sourceBlock_ as BlockSvg).workspace;
if (
!quietInput &&
this.workspace_.options.modalInputs &&
(userAgent.MOBILE || userAgent.ANDROID || userAgent.IPAD)
) {
this.showPromptEditor();
} else {
this.showInlineEditor(quietInput, manageEphemeralFocus);
}
}
/**
* Create and show a text input editor that is a prompt (usually a popup).
* Mobile browsers may have issues with in-line textareas (focus and
* keyboards).
*/
private showPromptEditor() {
dialog.prompt(
Msg['CHANGE_VALUE_TITLE'],
this.getText(),
(text: string | null) => {
// Text is null if user pressed cancel button.
if (text !== null) {
this.setValue(this.getValueFromEditorText_(text));
}
this.onFinishEditing_(this.value_);
},
);
}
/**
* Create and show a text input editor that sits directly over the text input.
*
* @param quietInput True if editor should be created without focus.
* @param manageEphemeralFocus Whether ephemeral focus should be managed as
* part of the field's inline editor (widget div).
*/
private showInlineEditor(quietInput: boolean, manageEphemeralFocus: boolean) {
const block = this.getSourceBlock();
if (!block) {
throw new UnattachedFieldError();
}
WidgetDiv.show(
this,
block.RTL,
this.widgetDispose_.bind(this),
this.workspace_,
manageEphemeralFocus,
);
this.htmlInput_ = this.widgetCreate_() as HTMLInputElement;
this.isBeingEdited_ = true;
this.valueWhenEditorWasOpened_ = this.value_;
if (!quietInput) {
(this.htmlInput_ as HTMLElement).focus({
preventScroll: true,
});
this.htmlInput_.select();
}
}
/**
* Create the text input editor widget.
*
* @returns The newly created text input editor.
*/
protected widgetCreate_(): HTMLInputElement | HTMLTextAreaElement {
const block = this.getSourceBlock();
if (!block) {
throw new UnattachedFieldError();
}
eventUtils.setGroup(true);
const div = WidgetDiv.getDiv();
const clickTarget = this.getClickTarget_();
if (!clickTarget) throw new Error('A click target has not been set.');
dom.addClass(clickTarget, 'blocklyEditing');
const htmlInput = document.createElement('input');
htmlInput.className = 'blocklyHtmlInput';
// AnyDuringMigration because: Argument of type 'boolean' is not assignable
// to parameter of type 'string'.
htmlInput.setAttribute(
'spellcheck',
this.spellcheck_ as AnyDuringMigration,
);
const scale = this.workspace_!.getAbsoluteScale();
const fontSize = this.getConstants()!.FIELD_TEXT_FONTSIZE * scale + 'pt';
div!.style.fontSize = fontSize;
htmlInput.style.fontSize = fontSize;
let borderRadius = FieldInput.BORDERRADIUS * scale + 'px';
if (this.isFullBlockField()) {
const bBox = this.getScaledBBox();
// Override border radius.
borderRadius = (bBox.bottom - bBox.top) / 2 + 'px';
// Pull stroke colour from the existing shadow block
const strokeColour = block.getParent()
? (block.getParent() as BlockSvg).getColourTertiary()
: (this.sourceBlock_ as BlockSvg).getColourTertiary();
htmlInput.style.border = 1 * scale + 'px solid ' + strokeColour;
div!.style.borderRadius = borderRadius;
div!.style.transition = 'box-shadow 0.25s ease 0s';
if (this.getConstants()!.FIELD_TEXTINPUT_BOX_SHADOW) {
div!.style.boxShadow =
'rgba(255, 255, 255, 0.3) 0 0 0 ' + 4 * scale + 'px';
}
}
htmlInput.style.borderRadius = borderRadius;
div!.appendChild(htmlInput);
htmlInput.value = htmlInput.defaultValue = this.getEditorText_(this.value_);
htmlInput.setAttribute('data-untyped-default-value', String(this.value_));
this.resizeEditor_();
this.bindInputEvents_(htmlInput);
return htmlInput;
}
/**
* Closes the editor, saves the results, and disposes of any events or
* DOM-references belonging to the editor.
*/
protected widgetDispose_() {
// Non-disposal related things that we do when the editor closes.
this.isBeingEdited_ = false;
this.isTextValid_ = true;
// Make sure the field's node matches the field's internal value.
this.forceRerender();
this.onFinishEditing_(this.value_);
if (
this.sourceBlock_ &&
eventUtils.isEnabled() &&
this.valueWhenEditorWasOpened_ !== null &&
this.valueWhenEditorWasOpened_ !== this.value_
) {
// When closing a field input widget, fire an event indicating that the
// user has completed a sequence of changes. The value may have changed
// multiple times while the editor was open, but this will fire an event
// containing the value when the editor was opened as well as the new one.
eventUtils.fire(
new (eventUtils.get(EventType.BLOCK_CHANGE))(
this.sourceBlock_,
'field',
this.name || null,
this.valueWhenEditorWasOpened_,
this.value_,
),
);
this.valueWhenEditorWasOpened_ = null;
}
eventUtils.setGroup(false);
// Actual disposal.
this.unbindInputEvents_();
const style = WidgetDiv.getDiv()!.style;
style.width = 'auto';
style.height = 'auto';
style.fontSize = '';
style.transition = '';
style.boxShadow = '';
this.htmlInput_ = null;
const clickTarget = this.getClickTarget_();
if (!clickTarget) throw new Error('A click target has not been set.');
dom.removeClass(clickTarget, 'blocklyEditing');
}
/**
* A callback triggered when the user is done editing the field via the UI.
*
* @param _value The new value of the field.
*/
onFinishEditing_(_value: AnyDuringMigration) {}
/**
* Bind handlers for user input on the text input field's editor.
*
* @param htmlInput The htmlInput to which event handlers will be bound.
*/
protected bindInputEvents_(htmlInput: HTMLElement) {
// Trap Enter without IME and Esc to hide.
this.onKeyDownWrapper = browserEvents.conditionalBind(
htmlInput,
'keydown',
this,
this.onHtmlInputKeyDown_,
);
// Resize after every input change.
this.onInputWrapper = browserEvents.conditionalBind(
htmlInput,
'input',
this,
this.onHtmlInputChange,
);
}
/** Unbind handlers for user input and workspace size changes. */
protected unbindInputEvents_() {
if (this.onKeyDownWrapper) {
browserEvents.unbind(this.onKeyDownWrapper);
this.onKeyDownWrapper = null;
}
if (this.onInputWrapper) {
browserEvents.unbind(this.onInputWrapper);
this.onInputWrapper = null;
}
}
/**
* Handle key down to the editor.
*
* @param e Keyboard event.
*/
protected onHtmlInputKeyDown_(e: KeyboardEvent) {
if (e.key === 'Enter') {
WidgetDiv.hideIfOwner(this);
dropDownDiv.hideWithoutAnimation();
} else if (e.key === 'Escape') {
this.setValue(
this.htmlInput_!.getAttribute('data-untyped-default-value'),
false,
);
WidgetDiv.hideIfOwner(this);
dropDownDiv.hideWithoutAnimation();
} else if (e.key === 'Tab') {
e.preventDefault();
const cursor = this.workspace_?.getCursor();
const isValidDestination = (node: IFocusableNode | null) =>
(node instanceof FieldInput ||
(node instanceof BlockSvg && node.isSimpleReporter())) &&
node !== this.getSourceBlock();
let target = e.shiftKey
? cursor?.getPreviousNode(this, isValidDestination, false)
: cursor?.getNextNode(this, isValidDestination, false);
target =
target instanceof BlockSvg && target.isSimpleReporter()
? target.getFields().next().value
: target;
if (target instanceof FieldInput) {
WidgetDiv.hideIfOwner(this);
dropDownDiv.hideWithoutAnimation();
const targetSourceBlock = target.getSourceBlock();
if (
target.isFullBlockField() &&
targetSourceBlock &&
targetSourceBlock instanceof BlockSvg
) {
getFocusManager().focusNode(targetSourceBlock);
} else getFocusManager().focusNode(target);
target.showEditor();
}
}
}
/**
* Handle a change to the editor.
*
* @param _e InputEvent.
*/
private onHtmlInputChange(_e: Event) {
// Intermediate value changes from user input are not confirmed until the
// user closes the editor, and may be numerous. Inhibit reporting these as
// normal block change events, and instead report them as special
// intermediate changes that do not get recorded in undo history.
const oldValue = this.value_;
// Change the field's value without firing the normal change event.
this.setValue(
this.getValueFromEditorText_(this.htmlInput_!.value),
/* fireChangeEvent= */ false,
);
if (
this.sourceBlock_ &&
eventUtils.isEnabled() &&
this.value_ !== oldValue
) {
// Fire a special event indicating that the value changed but the change
// isn't complete yet and normal field change listeners can wait.
eventUtils.fire(
new (eventUtils.get(EventType.BLOCK_FIELD_INTERMEDIATE_CHANGE))(
this.sourceBlock_,
this.name || null,
oldValue,
this.value_,
),
);
}
}
/**
* Set the HTML input value and the field's internal value. The difference
* between this and `setValue` is that this also updates the HTML input
* value whilst editing.
*
* @param newValue New value.
* @param fireChangeEvent 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.
*/
protected setEditorValue_(
newValue: AnyDuringMigration,
fireChangeEvent = true,
) {
this.isDirty_ = true;
if (this.isBeingEdited_) {
// In the case this method is passed an invalid value, we still
// pass it through the transformation method `getEditorText` to deal
// with. Otherwise, the internal field's state will be inconsistent
// with what's shown to the user.
this.htmlInput_!.value = this.getEditorText_(newValue);
}
this.setValue(newValue, fireChangeEvent);
}
/** Resize the editor to fit the text. */
protected resizeEditor_() {
renderManagement.finishQueuedRenders().then(() => {
const block = this.getSourceBlock();
if (!block) throw new UnattachedFieldError();
const div = WidgetDiv.getDiv();
const bBox = this.getScaledBBox();
div!.style.width = bBox.right - bBox.left + 'px';
div!.style.height = bBox.bottom - bBox.top + 'px';
// In RTL mode block fields and LTR input fields the left edge moves,
// whereas the right edge is fixed. Reposition the editor.
const x = block.RTL ? bBox.right - div!.offsetWidth : bBox.left;
const y = bBox.top;
div!.style.left = `${x}px`;
div!.style.top = `${y}px`;
});
}
/**
* Handles repositioning the WidgetDiv used for input fields when the
* workspace is resized. Will bump the block into the viewport and update the
* position of the text input if necessary.
*
* @returns True for rendered workspaces, as we never want to hide the widget
* div.
*/
override repositionForWindowResize(): boolean {
const block = this.getSourceBlock()?.getRootBlock();
// This shouldn't be possible. We should never have a WidgetDiv if not using
// rendered blocks.
if (!(block instanceof BlockSvg)) return false;
const bumped = bumpObjects.bumpIntoBounds(
this.workspace_!,
this.workspace_!.getMetricsManager().getViewMetrics(true),
block,
);
if (!bumped) this.resizeEditor_();
return true;
}
/**
* Use the `getText_` developer hook to override the field's text
* representation. When we're currently editing, return the current HTML value
* instead. Otherwise, return null which tells the field to use the default
* behaviour (which is a string cast of the field's value).
*
* @returns The HTML value if we're editing, otherwise null.
*/
protected override getText_(): string | null {
if (this.isBeingEdited_ && this.htmlInput_) {
// We are currently editing, return the HTML input value instead.
return this.htmlInput_.value;
}
return null;
}
/**
* Transform the provided value into a text to show in the HTML input.
* Override this method if the field's HTML input representation is different
* than the field's value. This should be coupled with an override of
* `getValueFromEditorText_`.
*
* @param value The value stored in this field.
* @returns The text to show on the HTML input.
*/
protected getEditorText_(value: AnyDuringMigration): string {
return `${value}`;
}
/**
* Transform the text received from the HTML input into a value to store
* in this field.
* Override this method if the field's HTML input representation is different
* than the field's value. This should be coupled with an override of
* `getEditorText_`.
*
* @param text Text received from the HTML input.
* @returns The value to store.
*/
protected getValueFromEditorText_(text: string): AnyDuringMigration {
return text;
}
}
/**
* Config options for the input field.
*
* @internal
*/
export interface FieldInputConfig extends FieldConfig {
spellcheck?: boolean;
}
/**
* A function that is called to validate changes to the field's value before
* they are set.
*
* @see {@link https://developers.google.com/blockly/guides/create-custom-blocks/fields/validators#return_values}
* @param newValue The value to be validated.
* @returns 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.
* @internal
*/
export type FieldInputValidator<T extends InputTypes> = FieldValidator<
string | T
>;