botbuilder-dialogs/src/prompts/choicePrompt.ts

A dialog stack based conversation manager for Microsoft BotBuilder.

/**
 * @module botbuilder-dialogs
 */
/**
 * Copyright (c) Microsoft Corporation. All rights reserved.
 * Licensed under the MIT License.
 */
import { Activity, TurnContext } from 'botbuilder-core';
import { ChoiceFactory, ChoiceFactoryOptions, FindChoicesOptions, FoundChoice, recognizeChoices } from '../choices';
import { ListStyle, Prompt, PromptOptions, PromptRecognizerResult, PromptValidator } from './prompt';
import { PromptCultureModels } from './promptCultureModels';

// Need ChoiceDefaultsProperty so we can set choiceDefaults dynamically with lambda
interface ChoiceDefaultsChoicePrompt {
    [locale: string]: ChoiceFactoryOptions;
}

/**
 * Prompts a user to select from a list of choices.
 *
 * @remarks
 * By default the prompt will return to the calling dialog a `FoundChoice` object containing the
 * choice that was selected.
 */
export class ChoicePrompt extends Prompt<FoundChoice> {
    /**
     * A dictionary of Default Choices based on [[PromptCultureModels.getSupportedCultures()]].
     * Can be replaced by user using the constructor that contains choiceDefaults.
     */
    private choiceDefaults: ChoiceDefaultsChoicePrompt;

    /**
     * The prompts default locale that should be recognized.
     */
    defaultLocale: string | undefined;

    /**
     * Style of the "yes" and "no" choices rendered to the user when prompting.
     *
     * @remarks
     * Defaults to `ListStyle.auto`.
     */
    style: ListStyle;

    /**
     * Additional options passed to the `ChoiceFactory` and used to tweak the style of choices
     * rendered to the user.
     */
    choiceOptions: ChoiceFactoryOptions | undefined;

    /**
     * Additional options passed to the underlying `recognizeChoices()` function.
     */
    recognizerOptions: FindChoicesOptions | undefined;

    /**
     * Creates a new `ChoicePrompt` instance.
     *
     * @param dialogId Unique ID of the dialog within its parent `DialogSet`.
     * @param validator (Optional) validator that will be called each time the user responds to the prompt. If the validator replies with a message no additional retry prompt will be sent.
     * @param defaultLocale (Optional) locale to use if `dc.context.activity.locale` not specified. Defaults to a value of `en-us`.
     * @param choiceDefaults (Optional) Overrides the dictionary of Bot Framework SDK-supported _choiceDefaults (for prompt localization).
     *  Must be passed in to each ConfirmPrompt that needs the custom choice defaults.
     */
    constructor(
        dialogId: string,
        validator?: PromptValidator<FoundChoice>,
        defaultLocale?: string,
        choiceDefaults?: ChoiceDefaultsChoicePrompt
    ) {
        super(dialogId, validator);
        this.style = ListStyle.auto;
        this.defaultLocale = defaultLocale;

        if (choiceDefaults == undefined) {
            const supported: ChoiceDefaultsChoicePrompt = {};
            PromptCultureModels.getSupportedCultures().forEach((culture): void => {
                supported[culture.locale] = {
                    inlineSeparator: culture.separator,
                    inlineOr: culture.inlineOr,
                    inlineOrMore: culture.inlineOrMore,
                    includeNumbers: true,
                };
            });
            this.choiceDefaults = supported;
        } else {
            this.choiceDefaults = choiceDefaults;
        }
    }

    /**
     * Prompts the user for input.
     *
     * @param context [TurnContext](xref:botbuilder-core.TurnContext), context for the current
     * turn of conversation with the user.
     * @param state Contains state for the current instance of the prompt on the dialog stack.
     * @param options A [PromptOptions](xref:botbuilder-dialogs.PromptOptions) object constructed
     * from the options initially provided in the call to Prompt.
     * @param isRetry `true` if this is the first time this prompt dialog instance
     * on the stack is prompting the user for input; otherwise, false.
     * @returns A `Promise` representing the asynchronous operation.
     */
    protected async onPrompt(
        context: TurnContext,
        state: any,
        options: PromptOptions,
        isRetry: boolean
    ): Promise<void> {
        // Determine locale
        const locale = this.determineCulture(context.activity);

        // Format prompt to send
        let prompt: Partial<Activity>;
        const choices =
            (this.style === ListStyle.suggestedAction ? ChoiceFactory.toChoices(options.choices) : options.choices) ||
            [];
        const channelId = context.activity.channelId;
        const choiceOptions = this.choiceOptions || this.choiceDefaults[locale];
        const choiceStyle: ListStyle = options.style === 0 ? 0 : options.style || this.style;
        if (isRetry && options.retryPrompt) {
            prompt = this.appendChoices(options.retryPrompt, channelId, choices, choiceStyle, choiceOptions);
        } else {
            prompt = this.appendChoices(options.prompt, channelId, choices, choiceStyle, choiceOptions);
        }

        // Send prompt
        await context.sendActivity(prompt);
    }

    /**
     * Attempts to recognize the user's input.
     *
     * @param context [TurnContext](xref:botbuilder-core.TurnContext) context for the current
     * turn of conversation with the user.
     * @param state Contains state for the current instance of the prompt on the dialog stack.
     * @param options A [PromptOptions](xref:botbuilder-dialogs.PromptOptions) object constructed
     * from the options initially provided in the call to Prompt.
     * @returns A `Promise` representing the asynchronous operation.
     */
    protected async onRecognize(
        context: TurnContext,
        state: any,
        options: PromptOptions
    ): Promise<PromptRecognizerResult<FoundChoice>> {
        const result: PromptRecognizerResult<FoundChoice> = { succeeded: false };
        const activity = context.activity;
        const utterance = activity.text;
        if (!utterance) {
            return result;
        }
        const choices =
            (this.style === ListStyle.suggestedAction ? ChoiceFactory.toChoices(options.choices) : options.choices) ||
            [];
        const opt = this.recognizerOptions || {};
        opt.locale = this.determineCulture(activity, opt);
        const results = recognizeChoices(utterance, choices, opt);
        if (Array.isArray(results) && results.length > 0) {
            result.succeeded = true;
            result.value = results[0].resolution;
        }

        return result;
    }

    /**
     * @private
     */
    private determineCulture(activity: Activity, opt?: FindChoicesOptions): string {
        const optLocale = opt && opt.locale ? opt.locale : null;
        let culture = PromptCultureModels.mapToNearestLanguage(
            activity.locale || optLocale || this.defaultLocale || PromptCultureModels.English.locale
        );
        if (!(culture && this.choiceDefaults[culture])) {
            culture = PromptCultureModels.English.locale;
        }

        return culture;
    }
}