Tutorial Server

Hi everyone!

This is a standalone server for the javascript tutorial https://javascript.info.

You can use it to run the tutorial locally and translate it into your language.

Windows, Unix systems and macOS are supported. For Windows, you'll need to call scripts with ".cmd" extension, that are present in the code alongside with Unix versions.

Installation

Install Git and Node.js.

These are required to update and run the project. For Windows just download and install, otherwise use standard OS install tools (packages or whatever convenient).

Please use Node.js 10+.

(Maybe later, optional) If you're going to change images, please install GraphicsMagick.
Install global Node modules:
```
npm install -g bunyan gulp@4
```
Create the root folder.

Create a folder /js for the project. If you use another directory as the root, adjust the paths below.
Clone the tutorial server into it:
```
cd /js
git clone https://github.com/javascript-tutorial/server
git clone https://github.com/javascript-tutorial/engine server/modules/engine
```
Please note, there are two clone commands. That's not a typo: modules/engine is cloned from another repository.
Clone the tutorial text into it.

The repository starts with the language code, e.g for the French version fr.javascript.info, for Russian – ru.javascript.info etc.

The English version is en.javascript.info.
```
cd /js
git clone https://github.com/javascript-tutorial/en.javascript.info
```
Run the site

Install local modules:
```
cd /js/server
npm install
```
Run the site with the same language. Above we cloned en tutorial, so:
```
./edit en
```
This will import the tutorial from /js/en.javascript.info and start the server.

Wait a bit while it reads the tutorial from the disk and builds static assets.

Then access the site at http://127.0.0.1:3000.
Edit the tutorial

As you edit text files in the tutorial text repository (cloned at step 5), the webpage will reload automatically.

Change server language

The server uses English by default for navigation and design.

You can set another language it with the second argument of edit.

E.g. if you cloned ru tutorial, it makes sense to use ru locale for the server as well:

cd /js/server
./edit ru ru

Please note, the server must support that language. There must be corresponding locale files for that language in the code of the server, otherwise it exists with an error. As of now, ru, en, zh, tr and ja are fully supported.

Translating images

The text in SVG pictures can be translated as well.

There's a special script for that. It takes images.yml from the repository root, like https://github.com/javascript-tutorial/ru.javascript.info/blob/master/images.yml, and then replaces strings in all svgs according to its content.

Here are the steps to translate images.

Step 1. Create images.yml with translations in the repository root.

The file format is "YAML", it's quite easy to understand:

code-style.svg:  # image file name
  "No space":    # English string
    text: "Без пробелов" # translation
    position: "center" # (optional) "center" or "right" - to position the translated string, details later

Step 2. Setup git upstream (if you haven't yet) and pull latest changes:

cd /js/zh.javascript.info # in the tutorial folder
git remote add upstream https://github.com/javascript-tutorial/en.javascript.info
git fetch upstream master

Step 3. Run the translation task:

cd /js/server # in the server folder
# adjust NODE_LANG to your language
NODE_LANG=zh glp engine:koa:tutorial:figuresTranslate

This script checks out all SVG images from upstream and replaces the strings according to images.yml.

Step 4. Then you'll need git add/commit/push the translated SVGs, as a part of the normal translation flow. You may want to open the translated SVGs directly in the browser to check them before doing so.

The --image parameter allows to translate a single image:

# replace strings only in try-catch-flow.svg
NODE_LANG=zh glp engine:koa:tutorial:figuresTranslate --image try-catch-flow.svg

For Windows: npm i -g cross-env and prepend the call with cross-env to pass environment variables, like this:
cd /js/server
cross-env NODE_LANG=zh...

The "overflowing text" problem

The translated string may become longer than the original.

The replacement script only operates on strings, not other graphics, so a long translated string may not fit the picture.

If you notice that, you usually can adjust the translation to make it shorter. Besides, most pictures have some extra space for longer text, so a slight increase doesn't harm.

If your translated string absolutely must be longer and doesn't fit, let me know, I can adjust the picture.

Positioning

By default, the translated string replaces the original one, in exactly the same place of the image:

| hello world (before)
| 你好世界  (after translation)

Sometimes that's not good, e.g. if the string needs to be centered in a vertical diagram.

The position: "center" in images.yml centers the translated string, so that it will replace the original one and stay "in the middle" of the surrounding context:

     |
hello world
  你好世界
     |

The position: "right" makes sure that the translated string sticks to the same right edge:

hello world |
    你好世界 |

P.S In order for positioning to work, you need to have ImageMagick installed: https://imagemagick.org/script/download.php (or use packages for Linux/MacOS).

Helper script: extract strings

The task to get all strings from an image as YAML (for translation, to add to images.yml):

cd /js/server
NODE_LANG=zh npm run gulp engine:koa:tutorial:imageYaml --image hello.svg

Dev mode

If you'd like to edit the server code (assuming you're familiar with Node.js), not the tutorial text, then there are two steps to do.

First, run the command that imports (and caches) the tutorial:

cd /js/server
NODE_LANG=en TUTORIAL_ROOT=/js/en.javascript.info npm run gulp engine:koa:tutorial:import

For Windows: npm i -g cross-env and prepend the call with cross-env to pass environment variables, like this:
cd /js/server
cross-env NODE_LANG=en...

In the code above, NODE_LANG sets server language, while TUTORIAL_ROOT is the full path to tutorial repo, by default is /js/$NODE_LANG.javascript.info.

Afterwards, call ./dev <server language> to run the server:

cd /js/server
./dev en

Running ./dev uses the tutorial that was imported and cached by the previous command.

It does not "watch" tutorial text, but it reloads the server after code changes.

Again, that's for developing the server code itself, not writing the tutorial.

Troubleshooting

Please ensure you have Node.js version 10+ (node -v shows the version).

If it still doesn't work – file an issue. Please mention OS and Node.js version.

Please pull the very latest git code and install latest NPM modules before publishing an issue.

-- Yours, Ilya Kantor iliakan@javascript.info

zixuan945/server