@loopback/boot/dist/bootstrapper.js

A collection of Booters for LoopBack 4 Applications

"use strict";
// Copyright IBM Corp. and LoopBack contributors 2018,2019. All Rights Reserved.
// Node module: @loopback/boot
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT
Object.defineProperty(exports, "__esModule", { value: true });
exports.Bootstrapper = void 0;
const tslib_1 = require("tslib");
const core_1 = require("@loopback/core");
const debug_1 = tslib_1.__importDefault(require("debug"));
const path_1 = require("path");
const keys_1 = require("./keys");
const mixins_1 = require("./mixins");
const types_1 = require("./types");
const debug = (0, debug_1.default)('loopback:boot:bootstrapper');
/**
 * The Bootstrapper class provides the `boot` function that is responsible for
 * finding and executing the Booters in an application based on given options.
 *
 * NOTE: Bootstrapper should be bound as a SINGLETON so it can be cached as
 * it does not maintain any state of it's own.
 *
 * @param app - Application instance
 * @param projectRoot - The root directory of the project, relative to which all other paths are resolved
 * @param bootOptions - The BootOptions describing the conventions to be used by various Booters
 */
let Bootstrapper = class Bootstrapper {
    constructor(app, projectRoot, bootOptions = {}) {
        this.app = app;
        this.projectRoot = projectRoot;
        this.bootOptions = bootOptions;
        // Resolve path to projectRoot and re-bind
        this.projectRoot = (0, path_1.resolve)(this.projectRoot);
        app.bind(keys_1.BootBindings.PROJECT_ROOT).to(this.projectRoot);
        // This is re-bound for testing reasons where this value may be passed directly
        // and needs to be propagated to the Booters via DI
        app.bind(keys_1.BootBindings.BOOT_OPTIONS).to(this.bootOptions);
    }
    /**
     * Function is responsible for calling all registered Booter classes that
     * are bound to the Application instance. Each phase of an instance must
     * complete before the next phase is started.
     *
     * @param execOptions - Execution options for boot. These
     * determine the phases and booters that are run.
     * @param ctx - Optional Context to use to resolve bindings. This is
     * primarily useful when running app.boot() again but with different settings
     * (in particular phases) such as 'start' / 'stop'. Using a returned Context from
     * a previous boot call allows DI to retrieve the same instances of Booters previously
     * used as they are bound using a CONTEXT scope. This is important as Booter instances
     * may maintain state.
     */
    async boot(execOptions, ctx) {
        var _a, _b, _c;
        const bootCtx = ctx !== null && ctx !== void 0 ? ctx : new core_1.Context(this.app);
        // Bind booters passed in as a part of BootOptions
        // We use _bindBooter so this Class can be used without the Mixin
        if (execOptions === null || execOptions === void 0 ? void 0 : execOptions.booters) {
            execOptions.booters.forEach(booter => (0, mixins_1.bindBooter)(this.app, booter));
        }
        // Determine the phases to be run. If a user set a phases filter, those
        // are selected otherwise we run the default phases (BOOTER_PHASES).
        const phases = (_b = (_a = execOptions === null || execOptions === void 0 ? void 0 : execOptions.filter) === null || _a === void 0 ? void 0 : _a.phases) !== null && _b !== void 0 ? _b : types_1.BOOTER_PHASES;
        // Find booters registered to the BOOTERS_TAG by getting the bindings
        const bindings = bootCtx.findByTag(keys_1.BootTags.BOOTER);
        // Prefix length. +1 because of `.` => 'booters.'
        const prefixLength = keys_1.BootBindings.BOOTERS.length + 1;
        // Names of all registered booters.
        const defaultBooterNames = bindings.map(binding => binding.key.slice(prefixLength));
        // Determining the booters to be run. If a user set a booters filter (class
        // names of booters that should be run), that is the value, otherwise it
        // is all the registered booters by default.
        const names = execOptions
            ? ((_c = execOptions.filter) === null || _c === void 0 ? void 0 : _c.booters)
                ? execOptions.filter.booters
                : defaultBooterNames
            : defaultBooterNames;
        // Filter bindings by names
        const filteredBindings = bindings.filter(binding => names.includes(binding.key.slice(prefixLength)));
        // Resolve Booter Instances
        const booterInsts = await (0, core_1.resolveList)(filteredBindings, binding => 
        // We cannot use Booter interface here because "filter.booters"
        // allows arbitrary string values, not only the phases defined
        // by Booter interface
        bootCtx.get(binding.key));
        // Run phases of booters
        for (const phase of phases) {
            for (const inst of booterInsts) {
                const instName = inst.constructor.name;
                if (inst[phase]) {
                    debug(`${instName} phase: ${phase} starting.`);
                    await inst[phase]();
                    debug(`${instName} phase: ${phase} complete.`);
                }
                else {
                    debug(`${instName} phase: ${phase} not implemented.`);
                }
            }
        }
        return bootCtx;
    }
};
exports.Bootstrapper = Bootstrapper;
exports.Bootstrapper = Bootstrapper = tslib_1.__decorate([
    tslib_1.__param(0, (0, core_1.inject)(core_1.CoreBindings.APPLICATION_INSTANCE)),
    tslib_1.__param(1, (0, core_1.inject)(keys_1.BootBindings.PROJECT_ROOT)),
    tslib_1.__param(2, (0, core_1.inject)(keys_1.BootBindings.BOOT_OPTIONS, { optional: true })),
    tslib_1.__metadata("design:paramtypes", [Object, String, Object])
], Bootstrapper);
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