Angular library with basic elements and for communication with the lenne.Tech Nest Server

angular, apollo, graphql, apollo-client, apollo-angular, angular-library, angular11+, best-practices, communication, helpers-library, library, services
npm install @lenne.tech/ng-base@0.0.9


Angular Base

This is the base library of lenne.Tech for Angular. It contains the npm package ng-base.


This library contains all the basics to start a new project in combination with the lenne.Tech Nest Server:

  • GraphQL service and elements for easy communication with GraphQL API (via Models)
  • Standard Model with methods for mapping, cloning and comparing models
  • Basic User Model with basic rights handling
  • Loading Service for the subscription of loading processes
  • Storage Service for comfortable saving of data in local storage
  • GraphQL service and elements for easy communication with GraphQL API (via Models)
  • Authentication service for user registration
  • and much more

The detailed description of the features and instructions on how to use the library can be found in the README.md of the library.

For setting up a new project we recommend our Angular Starter, which already contains this library and also includes a few sample elements as templates.


Test the package

npm run pack

Afterwards, the package can be included in an Angular project as follows in the package.json on a test basis:

  "dependencies": {
    "@lenne.tech/ng-graphql-client": "file:/PATH_TO_PROJECT/ng-base/dist/graphql-client/lenne.tech-ng-base-X.X.X.tgz"


Update version in projects/graphql-client/package.json and projects/graphql-client/package-lock.json.

After that, the new package can be published as follows:

npm run publish

Initialize log

The initialization of this library is inspired by The Best Way To Architect Your Angular Libraries from Thomas Trajan.

Init library

Init Angular

ng new ng-base --createApplication false --prefix lt
ng g library ng-base --prefix lt

Change package name in projects/ng-base/src

"name": "@lenne.tech/ng-base"

Replace path configuration in tsconfig.json:

  "paths": {
    "@lenne.tech/ng-base/*": ["projects/ng-base/*", "projects/ng-base"],
    "@lenne.tech/ng-base": ["dist/ng-base/*", "dist/ng-base"]

Delete the content of the projects/some-lib/src/lib/ folder and remove content of the root public-api.ts file so that it’s empty.

Install ng-samurai to extend the Angular CLI for creating Sub-entries:

npm i -D ng-samurai

Create new Sub-entry (without component --gc false and module --gm false):

ng g ng-samurai:generate-subentry core --gc false --gm false


Migration from TSLint (depracted since 2019) to ESLint (see Migrationsanleitung):

ng add @angular-eslint/schematics
ng g @angular-eslint/schematics:convert-tslint-to-eslint ng-base
rm tslint.json
npm uninstall tslint
npm uninstall codelyzer

Additional rules in .eslintrc.json:

  "overrides": [
      "rules": {
        "no-underscore-dangle": "off"

Install Prettier and prettier-quick:

npm install --save-dev --save-exact prettier
npm install --save-dev pretty-quick

Add file .prettierrc:

  "arrowParens": "always",
  "plugins": ["./extras/prettier-imports"],
  "printWidth": 120,
  "singleQuote": true

Add file extras/prettier-imports.js:

const { parsers: typescriptParsers } = require('prettier/parser-typescript');
const ts = require('typescript');

// =============================================================================
// Prettier plugin to optimize and sort imports
// see https://github.com/prettier/prettier/issues/6260
// =============================================================================

class SingleLanguageServiceHost {
  constructor(name, content) {
    this.name = name;
    this.content = content;
    this.getCompilationSettings = ts.getDefaultCompilerOptions;
    this.getDefaultLibFileName = ts.getDefaultLibFilePath;
  getScriptFileNames() {
    return [this.name];
  getScriptVersion() {
    return ts.version;
  getScriptSnapshot() {
    return ts.ScriptSnapshot.fromString(this.content);
  getCurrentDirectory() {
    return '';

function applyChanges(text, changes) {
  return changes.reduceRight((text, change) => {
    const head = text.slice(0, change.span.start);
    const tail = text.slice(change.span.start + change.span.length);
    return `${head}${change.newText}${tail}`;
  }, text);

function organizeImports(text) {
  const fileName = 'file.ts';
  const host = new SingleLanguageServiceHost(fileName, text);
  const languageService = ts.createLanguageService(host);
  const formatOptions = ts.getDefaultFormatCodeSettings();
  const fileChanges = languageService.organizeImports({ type: 'file', fileName }, formatOptions, {});
  const textChanges = [...fileChanges.map((change) => change.textChanges)];
  return applyChanges(text, textChanges);

const parsers = {
  typescript: {
    preprocess(text) {
      text = organizeImports(text);
      return text;

// Uses module.export because of 'Unexpected token export' error
module.exports = parsers;

Add scripts in package.json:

"scripts": {
  "format:check": "prettier --config ./.prettierrc --list-different \"src/{app,environments,assets}/**/*{.ts,.js,.json,.scss}\"",
  "format:fix": "pretty-quick --staged",
  "format:fixAll": "prettier --write src",

format:check: Check only
format:fix: Optimize stage files
format:fixAll: Optimize all files

Automatic optimizations and checks

Install husky:

npm install --save-dev husky

Add scripts in package.json:

"scripts": {
  "check": "npm run format:fix && npm run lint",
  "postinstall": "husky install .husky",

Add pre-commit hook:

mkdir .husky
npx husky add .husky/pre-commit "cd $(dirname "$0") && npm run check"

Init husky via npm i.

Optimize TypeScript config

To get a little more leeway in dealing with TypeScript's strict typing, the following rules should be disabled in compilerOptions of tsconfig.json:

  "compilerOptions": {
    "strictNullChecks": false,
    "strictPropertyInitialization": false,
    "noImplicitAny": false


Many thanks to the developers of Angular, Apollo Angular and all the developers whose packages are used here.