CategoryWeb Technologies

VSCode: Launch create-react-app and Chrome with launch.json

Developing React (with create-react-app) and Visual Studio Code you usually press ESC-` and then npm start.
The script from create-react-app then automatically starts a Browser. That you then close.
hen reopen by pressing F5 to start Chrome in debug mode.

Let’s make these steps a little quicker.

Create a Task for npm start

Press Ctrl-Shift- and Select “Tasks: Configure Default Test Task”
This will create a tasks.json file.

In the tasks.json file you need to add a couple of values:
* isBackground: true – launch.json will not wait untill the task completes
* problemMatcher Needs to be defined to figure out when the task has completet its initialisation phase and it is safe to continue with the next task

Configure create-react-app

To prevent launching the browser you need to add in your .env-file following line:

BROWSER=none

More Info:
* .env-file

Configure the Launch.json file

Press F5 and select Chrome and a launch.json file will be created.
* Change the port to 3000 (create-react-app default)
* Add a preLaunchTask to start the task we defined earlier

Start Working

Tadaa, now you press F5 and can start debugging directly in vscode. The background task will continue running even when you stop debugging.

Stop Working

You need to terminate the task via ctrl-shift-p > terminate Task. (Or you just close vscode)

DEV281x: Introduction to ReactJS

I took a quick look at Microsoft Introduction to ReactJS, not to actually learn React, but to evaluate how good the materials are for a beginner to learn React.

tl;dr
Avoid the assessment. Maybe use create-react-app instead of codepen.
Covers the basics quite well.

Lesson 01 | JSX and React Components

Instead of using “create-react-app” as a starting point, the course tells you to go to codepen to check out react.

I guess that makes it a little more focused on the React concepts and less focused on all the surrounding technologies that are needed in an production environment.

After that it covers the basics of ReactJS, and JSX.

If you are a beginner you probably want to check out create-react-app.

Lesson 02 | State, Life Cycle and Event Handlers

I think the chapter covers the basics quite well. Nothing really to add here.

Lesson 03 | Lists and Forms

Here i think it is very nice that they cover the basics of handling multiple Form Elements with a generic handler.

Assessment

The Assessment is quite theoretical and asks rather complicated questions. These questions are especially hard if you have already worked with React as you would never even try to build something in that way.

As a beginner I would completely skip the Assesment. It does not help you to further your understanding of React. It actually also confronts you with bad practices, while inferring that this would be the way how you would actually do things

Conclusion

If you use create-react-app with vscode I think you would have a much better starting experience.
The course is great to get started with ReactJS, if you avoid the assesments and rather just experiment with your own code base.

package.json: Updating Fixed Versions with npm-check

One of the common problems when running a larger project is that you need to use fixed versions in your package.json file. But at the same time you need to regularly update your packages.
The most elegant way is using npm-check. The small tool allows you to select which packages should get an update and update accordingly.

Installation

npm i -g npm-check

Usage

To update the packages in your project you now simply run npm-check -u. If you want to ensure that you are installing the exact package run it with the additional optional flag -E to ensure exact-versions.

npm-check -u -E

With Space you select the packages and with Enter you install the package.

Disable the package-lock.json file

With NPM 5, npm has started to create a “package-lock.json” file.
It ensures that some dependency tree is identical on every developers environment. Official Documentation.

Now, that may be important on some projects. In my personal projects I do not really care. And in the professional projects I did not have any issues how things were done before.

Actually with the new way of doing things, you must first remove the package-lock.json file and then run “npm update” to install newer versions of stuff. Then again, this can cause problems as when some other person also creates the package-lock file, or a merge conflict occurs etc. In the end totally defeating the purpose of the file.

Disabling the Package Lock File for a Project

  1. Create a file called .npmrc
  2. Open the file and add the line package-lock=false

Global Disable

If you currently want to disable the behavior on all projects run

npm config set package-lock false

In the future the feature may be more easy to use. For now I at least will stick to the old way of how to do things.

Notes on Course: Microsoft – Advanced CSS Concepts

My notes on the great course Microsoft – Advanced CSS Concepts on edx.

Lesson 01

Responsive Layout

Covers the basics of Responsive Layout.
In essence you use the @media query to figure out what
the width, height, page orientation and resolution of the device is.
Then based on that information you use a different CSS Rule.

To create a consistent Layout you should always design for the smallest device screen – then expand it to the bigger devices.
(Mobile First Strategy).

Base CSS

In General you should use a Style guide to create a consistent look
across your application. They are usually created by the graphic designer.

Typically a website should be suitable for all different types of browsers.
However the CSS implementation and the default styles are different across browsers.
To avoid this problem, you can include a CSS Reset – to ensure a consistent style.

A front end Style guide should help define
* Code standardization of CSS, and HTML
* Consistency of code and design
* More efficient workflow
* Documenting of code practices
* An easy-to-access reference for code and design for new team members

Your style guide will be comprised of:

  • A template: The template contains the basic elements that serve as the foundation for your web page, such as color palette, fonts, headers, footers, body text, navigation, widgets, and grid layouts.
  • Patterns: The patterns for your web page include buttons, logos, images, the font icon library, and form styles.
  • Documentation: The documentation is a record of the style and development pattern of your web page. You can add comments in your code that serve as the style guide or use interactive modals or tool tips.

Media Queries

The most commonly used media queries are:

  • min-width Rules applied for any browser width over the value defined in the query
  • max-width Rules applied for any browser width below the value defined in the query
  • min-height Rules applied for any browser height over the value defined in the query
  • max-height Rules applied for any browser height below the value defined in the query
  • orientation:portrait Rules applied for any browser where the height is greater than or equal to the width
  • orientation:landscape Rules for any browser where the width is greater than the height

The Query information is then used to define breakpoints, points where the layout switches from one size to another.
Example of a set of major device breakpoints:

/* Extra small devices (phones, up to 480px) */
@media screen and (max-width: 767px) {…}

/* Small devices (tablets, 768px and up) */
@media (min-width: 768px) and (max-width: 991px) {…}

/* tablets/desktops and up */
@media (min-width: 992px) and (max-width: 1199px) {…}

/* large like desktops and up */
@media screen and (min-width: 1200px) {…}

Units

Historically the “px” Unit was used, however to incorporate various resolutions it is better to use the “rem” unit.

Going forward

  • Optimize the text for reading
  • Use major device breakpoints, and address content with minor breakpoints
  • Treat your website’s layout as an enhancement
  • Use relative units like rem or em;

Working with images

Images should be resampled to three different media sizes

Note: The alt tag must be set to correctly validate.

Lesson 02

Modular CSS

Modular CSS is:

  • A guideline based approach for breaking down pages into generic reusable CSS code.
  • Based on classes and consistent naming conventions.
  • Easy to read and maintain by teams.

CSS Modules are:

  • Generic, self-contained, and reusable.
  • Modifiable, combinable, and scalable.
  • Can contain or be contained by other modules but stay independent.

What are some common modules?

You will often come across modules such as these:

Example Module

What are the Results of a Module Based Approach?

  • Faster development
  • Flexible and scalable code
  • Code reuse
  • Organized and easy to read code
  • Easier to maintain
  • Team efficiency
  • Decoupled HTML and CSS

Guidlines

  1. OOCSS (Object Oriented CSS) | http://oocss.org/
  2. SMACSS (Scalable and Modular Architecture for CSS) | https://smacss.com/
  3. BEM (Block, Element, Modifier) http://getbem.com/
  4. DRY (Don’t Repeat Yourself CSS)

Font Awesome

A popular set of icon fonts is Font Awesome (http://fontawesome.io/)

Example for a like button

Git: Hooks run “npm install” on checkout

When working on a project you usually install various packages from npm.
Of course these packages are maintained and updated, adding more features and security fixes, and stability patches.

One person on your team should run npm outdated once per week to see what all has been updated and test if you can integrate the packages into your project.
Thus the package.json is updated and causes a grand problem for all other developers on the project. If a package has major breaking changes the code will need to be adjusted, however that code will not run on the other develoepers environment. The other developers working on the project they have to run npm update to install the missing / outdated packages in their environment.

The solution to this problem are “git hooks”, essentially git can execute code on specific events, like before commiting your code, or pre push etc.
git hooks. For my use case I would like to run npm update after a developer checks out from the git repository, this is the event “post-checkout”.

Native Git Hooks

To create a git hook you need to add a file in your project called .git/hooks/post-checkout (On linux add the executable bit with chmod +x)

You will test this and say, yes this works as intended – lets commit it to the repository. – Now you will discover that you cannot commit files in .git to the repository.
In fact git does not allow you to do this, due to security concerns as git hooks can execute any shell script.

The work around for this issue is to simply add it into a folder called git-hooks/ and tell the developers to copy the file when they set up their dev environment.

Husky

As always if there is a Problem for development with javascript there is a npm package to solve the problem.
Husky uses the package.json to define the scripts that are executed via git hooks.
Simply Install Husky
npm install husky -D

Then edit the package.json:

The Husky solution would also allow you to execute your own js file, maybe also doing some cleanup of files or running tests etc.

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