ltijs/services/deep-linking/deep-linking.service.js

Easily turn your web application into a LTI 1.3 Learning Tool.

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.DeepLinking = void 0;
const node_path_1 = __importDefault(require("node:path"));
const id_token_constants_1 = require("#services/launch/id-token.constants");
const jwt_1 = require("#utils/crypto/jwt");
const jwt_constants_1 = require("#utils/crypto/jwt.constants");
const random_1 = require("#utils/random/random");
const template_renderer_1 = require("#utils/templating/template-renderer");
const html_escape_1 = require("#utils/templating/html-escape");
const validation_1 = require("#utils/validation/validation");
const deep_linking_schemas_1 = require("#services/deep-linking/deep-linking.schemas");
const errors_1 = require("#services/deep-linking/errors");
const platform_keys_1 = require("#services/platform-manager/platform-keys");
class DeepLinking {
    LOG_COMPONENT = 'deepLinkingService';
    RESPONSE_TTL_SECONDS = 60;
    RESPONSE_MESSAGE_TYPE = 'LtiDeepLinkingResponse';
    DEEP_LINKING_SUBMISSION_FORM_TEMPLATE = node_path_1.default.join(__dirname, 'templates', 'deep-linking-submission-form.spy');
    CONTENT_ITEMS_CLAIM = 'https://purl.imsglobal.org/spec/lti-dl/claim/content_items';
    MSG_CLAIM = 'https://purl.imsglobal.org/spec/lti-dl/claim/msg';
    ERROR_MSG_CLAIM = 'https://purl.imsglobal.org/spec/lti-dl/claim/errormsg';
    LOG_CLAIM = 'https://purl.imsglobal.org/spec/lti-dl/claim/log';
    ERROR_LOG_CLAIM = 'https://purl.imsglobal.org/spec/lti-dl/claim/errorlog';
    DATA_CLAIM = 'https://purl.imsglobal.org/spec/lti-dl/claim/data';
    launchContext;
    logger;
    constructor(launchContext, logger) {
        this.launchContext = launchContext;
        this.logger = logger;
    }
    /** Whether this launch is a deep-linking launch. Check before calling any other method on this service. */
    isAvailable() {
        return this.launchContext.idToken.services.deepLinking.available;
    }
    async createDeepLinkingMessage(contentItems, options) {
        this.ensureServiceAvailability();
        const { platform, rawIdToken: idToken } = this.launchContext;
        const settings = this.resolveDeepLinkingSettings(idToken);
        return await this.signDeepLinkingMessage({ idToken, platform, settings, contentItems, options });
    }
    async createDeepLinkingForm(contentItems, options) {
        this.ensureServiceAvailability();
        const { platform, rawIdToken: idToken } = this.launchContext;
        const settings = this.resolveDeepLinkingSettings(idToken);
        const message = await this.signDeepLinkingMessage({ idToken, platform, settings, contentItems, options });
        return (0, template_renderer_1.renderTemplate)(this.DEEP_LINKING_SUBMISSION_FORM_TEMPLATE, {
            action: (0, html_escape_1.escapeHtmlAttribute)(settings.deep_link_return_url ?? ''),
            message,
        });
    }
    async signDeepLinkingMessage(request) {
        const { idToken, platform, settings, contentItems, options } = request;
        const items = (0, validation_1.validate)(deep_linking_schemas_1.ContentItemsInputSchema, contentItems);
        const accepted = this.filterContentItems(items, settings);
        const payload = {
            iss: platform.clientId,
            aud: idToken.iss,
            nonce: (0, random_1.randomJti)(),
            [id_token_constants_1.IdTokenClaim.DeploymentId]: idToken[id_token_constants_1.IdTokenClaim.DeploymentId],
            [id_token_constants_1.IdTokenClaim.MessageType]: this.RESPONSE_MESSAGE_TYPE,
            [id_token_constants_1.IdTokenClaim.Version]: idToken[id_token_constants_1.IdTokenClaim.Version],
            [this.CONTENT_ITEMS_CLAIM]: accepted,
        };
        const errMessage = options?.errMessage ?? options?.errmessage;
        const errLog = options?.errLog ?? options?.errlog;
        if (options?.message !== undefined)
            payload[this.MSG_CLAIM] = options.message;
        if (errMessage !== undefined)
            payload[this.ERROR_MSG_CLAIM] = errMessage;
        if (options?.log !== undefined)
            payload[this.LOG_CLAIM] = options.log;
        if (errLog !== undefined)
            payload[this.ERROR_LOG_CLAIM] = errLog;
        if (settings.data !== undefined)
            payload[this.DATA_CLAIM] = settings.data;
        this.logger.debug(this.LOG_COMPONENT, `Signing deep linking response with ${accepted.length} content item(s)`);
        return (0, jwt_1.signJwt)(payload, (0, platform_keys_1.resolvePlatformPrivateKey)(platform), {
            algorithm: jwt_constants_1.RS256_ALGORITHM,
            expiresIn: this.RESPONSE_TTL_SECONDS,
            keyid: platform.id,
        });
    }
    ensureServiceAvailability() {
        if (!this.isAvailable())
            throw new errors_1.DeepLinkingNotAvailableError();
    }
    resolveDeepLinkingSettings(idToken) {
        const settings = idToken[id_token_constants_1.IdTokenClaim.DeepLinkingSettings];
        if (settings === undefined)
            throw new errors_1.MissingDeepLinkSettingsError();
        return settings;
    }
    filterContentItems(items, settings) {
        const acceptedTypes = settings.accept_types ?? [];
        // `accept_multiple` arrives from an external, platform-controlled id_token claim; the declared
        // `boolean` type isn't a runtime guarantee. Some platforms send the string 'false' instead of the
        // boolean, so both must be treated the same way here, not just the boolean.
        const rawAcceptMultiple = settings.accept_multiple;
        const acceptMultiple = rawAcceptMultiple !== false && rawAcceptMultiple !== 'false';
        const accepted = [];
        for (const item of items) {
            if (!acceptedTypes.includes(item.type))
                continue;
            accepted.push(item);
            if (!acceptMultiple)
                break;
        }
        return accepted;
    }
}
exports.DeepLinking = DeepLinking;
exports.default = DeepLinking;
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