dependency injection parameters - javascript

I am trying to clean my code and make it maintainable and testable so i am applying dependency injection
but i have faced alot of questions ..
First lets see my folder structure ..
User // Folder
index.js
User.js
DAL
services
etc(routes,controller)
in services i have to do DI so my services class should be like this
class UserServices {
constructor(DAL) {
this.DAL = DAL;
}
getAllUsers() {
return this.DAL.getAllUsers();
}
}
module.exports = UserServices;
and so on for the DAL it will recieve the Database in the constructor instead of DAL in the previous ex.
Now my question is ..
-Where do i give the User class the parameters if i am exporting the class not the instance ? (btw should i export the class or the instance ?)
Should i add the npm packages to the parameters too (nodemailer, jwt,etc)?
and if yes where should i give the parameters ?
i dont think in the controller because thats breaks the idea of the clean code..
Any helpful resource will be helpful alot..
Thanks for your time i appreciate it

Related

Include JSON files into React build

I know this question maybe exist in stack overflow but I didn't get any good answers, and I hope in 2020 there is better solution.
In my react app I have a config JSON file, it contains information like the title, languages to the website etc..
and this file is located in 'src' directory
{
"headers":{
"title":"chat ",
"keys":"chat,asd ,
"description":" website"
},
"languages":{
"ru":"russian",
"ar":"arabic",
"en":"English"
},
"defaultLanguage":"ru",
"colors":{
"mainColor":"red",
"primary":"green",
"chatBackGround":"white"
}
}
I want to make my website easy to edit after publishing it, but after I build my app, I can't find that settings.json file there in build directory.
I find out that files in public directory actually get included to build folder, I tried to put my settings.JSON in public,
but react won't let me import anything outside of src directory
I found other solutions like this one but didn't work
https://github.com/facebook/create-react-app/issues/5378
Also I tried to create in index.html a global var like (window.JSON_DATA={}), and attach a JS object to it and import it to App.js, but still didn't work.
How can I make a settings JSON file, and have the ability to edit it after publishing the app?
Add your settings.json to the public folder. React will copy the file to the root of build. Then load it with fetch where you need it to be used. For example if you need to load setting.json to the App.js then do the next:
function App() {
const [state, setState] = useState({settings: null});
useEffect(()=>{
fetch('settings.json').then(response => {
response.json().then(settings => {
// instead of setting state you can use it any other way
setState({settings: settings});
})
})
})
}
If you use class-components then do the same in componentDidMount:
class CustomComponent extends React.Component {
constructor(props) {
super(props);
this.state = {settings: null};
}
componentDidMount() {
fetch('settings.json').then(response => {
response.json().then(settings => {
this.setState({settings: settings});
})
})
}
}
Then you can use it in render (or any other places of your component):
function App() {
...
return (
{this.state.settings && this.state.settings.value}
)
}
The easiest way would be to require() the file on the server during server side rendering of the html page and then inline the json in the html payload in a global var like you mentioned window.JSON_DATA={}. Then in your js code you can just reference that global var instead of trying to use import.
Of course this approach would require you to restart your server every time you make a change to the json file, so that it get's picked up. If that is not an option then you'll need to make an api call on the server instead of using require().
You may want to look at using npm react-scripts (https://www.npmjs.com/package/react-scripts) to produce your react application and build. This will package will create a template that you can put your existing code into and then give you a pre-configure build option that you can modify if you would like. The pre-configured build option will package your .json files as well. Check out their getting started section (https://create-react-app.dev/docs/getting-started/)
If you don't want to go that route, and are just looking for quick fix, then I would suggest change your json files to a JS file, export the JS object and import it in the files you need it since you seem to be able to do that.
//src/sampledata.js
module.exports = {
sample: 'data'
}
//src/example.jsx (this can also be .js)
const sampledata = require('./sampledata');
console.log(sampledata.sample); // 'data'
you can use 'Fetch Data from a JSON File'
according to link
https://www.pluralsight.com/guides/fetch-data-from-a-json-file-in-a-react-app
example

Import dynamically named exports

Is it possible to import named exports dynamically?
I have a file, banana.js with hundreds of named exports. Id like to import them on demand. Is this possible? And if it is, will it only load that export and not all?
I know its possible to import them dynamically from individual files but I want them in the same file.
Example below..
// banana.js
export const banana_1 = {
..
}
export const banana_2 = {
..
}
// main.js
const currentPage = 1
async getSomething(){
let { `banana_${currentPage}` } = await import('./banana.js');
const foo = `banana_${currentPage}`
}
Fyi im using Vue.js
From what I know, you might have to use require('./banana.js') here. Please note that require is synchronous, so need for await. If you use eslint and it forbids usage of require, just add // eslint-disable-line to the end of that line. BTW, I don't know Vue at all.
About the object you import, you should probably make an array instead of suffixing each export with a number.
Edit: I just realized that dynamic imports are a thing not only possible with require, so ignore the first paragraph.
Based on your response to my question I offer the following solution. I understand not wanting to deploy and use a full database solution for the sake of hot loading some JSON objects. I'm unsure of your use case and other details related to your project.
You can use a self contained database like SQLite. Instead of setting up a NoSQL or SQL server. You can instead just store what you need to the SQLite file. Since Vue requires Node.js you can use the Node.js SQLite3 library https://www.npmjs.com/package/sqlite3.
I hope this helps.

Create base class for controller to extend/inherit in Ember application

I'm trying to create a Base Class for my controllers, so I can avoid duplication of code.
The problem here is that it is throwing me errors whenever I try to use it.
"Assertion Failed: You attempted to define a {{link-to "inventory"}} but did not pass the parameters required for generating its dynamic segments. Could not find module controllers/base-inventory imported from frontend/controllers/inventory"
To create my base controller I am using ember cli and this is what I did:
ember g controller base-inventory
Then
// base-inventory.js
const BaseInventory = Ember.Controller.extend({
//my code...
});
export default BaseInventory;
In the controller where I want to use this base class I did the following
import BaseInventory from 'controllers/base-inventory';
// also tried import { BaseInventory } from 'controllers/base-inventory';
// and export default new BaseInventory({});
export default BaseInventory.extend({
//more code here...
});
Any thoughts of what I am doing wrong?
I didn't plan to use mixins, because it doesn't seem the best option here at first. I am not really sure about the sharing content, which mixins provide. I don't think it would be a problem since I'm trying to inherit within controllers, but as I said I'm not sure about how it really works.
If it's not possible to do the way I'm trying to, I'll write a mixin.
Both files are in the same folder structure so import path should be like ./base-inventory
import BaseInventory from './base-inventory';

meteor: import directory - modular import of methods which are needed

I'm migrating my meteor application to the import-function of meteor 1.3.
But I think this is not quite the best way it should be done. Isn't it possible to load/import just the method which is really needed?
I mean, right now just all methods are loaded by importing the the methods.js. But I would like to do that in a modular way. So if the form .fomNewElement is used in the app, the method insertArticle will be imported and so on. Not just loading everything...
Below you can see my folder structure for /imports and some content of the files. Is there anything more I could improve in the structure itself?
Also it would be great if the import would depend on user roles. Is this possible?
imports/api/article/client/article.js
import { Articles } from '../';
import { insertArticle, updateArticle } from '../methods.js';
Template.Articles.helpers({
// some helpers
});
Template.Artilces.onCreated(function() {
// some code
});
Template.Artilces.onRendered(function() {
// some code
});
Template.Articles.events({
'submit .formNewElement': function(event) {
event.preventDefault();
var title = event.target.title.value.trim();
insertArticle.call({
title: title
});
},
'click .anything': function() {}
});
As you can see, I put into that js-file all helpers, events and onCreated/onRendered code. Hope this is 'correct'... Please give me some hint, if this isn't very smart.
imports/api/article/index.js
export const Articles = new Mongo.Collection('articles');
imports/api/article/methods.js
import { Articles } from './';
export const insertArticle = new ValidatedMethod({
name: 'article.insert',
validate: new SimpleSchema({
title: { type: String }
}).validator(),
run( document ) {
Articles.insert( document );
}
});
export const updateArticle = new ValidatedMethod({
name: 'article.update',
validate: new SimpleSchema({
_id: { type: String },
'update.title': { type: String }
}).validator(),
run( { _id, update } ) {
Articles.update( _id, { $set: update } );
}
});
And the other files:
imports/startup/client/index.js
import '../../api/redactor-article/client';
imports/startup/server/index.js
import '../../api/redactor-article/server/publications.js';
import '../../api/redactor-article/methods.js';
imports/api/article/client/index.js
import './article.html';
import './article.sass';
import './article.js';
Filestructure
/imports
/api
/article
/client
article.html
article.js
article.sass
index.js
/server
publications.js
index.js
methods.js
Update
Maybe it would be a better way to structure an import module like this:
imports/
api/
articles/
publication.js
methods.js
collection.js
ui/
articles/
article.html
article.css
article.js // contains helpers, events and onCreated/onRendered
Then I have to import the files in startup/client (-> all ui files of this module AND all api files) and startup/server (-> just all api files)...
Right?
A few points:
You've put everything under imports/api. That directory is designed for collections, methods, helpers, 'business logic' and public API (e.g. if you expose a REST API, you'd do it from within that directory). Use imports/ui for your templates (including their styles and associated .js files).
You don't need to differentiate between client and server directories within imports. Just import the files you need from the respective main entry points (i.e. client/main.js and server/main.js). This point is a little more complex than I suggest here, see the link to 'structure' in the Meteor Guide, below.
index.js doesn't seem like a logical place to put your Articles collection. I'd make a file at /imports/api/articles/articles.js for it. See http://guide.meteor.com/structure.html for a good overview about where to put things and why.
Also, in the interests of following best-practices, use a default export for your Articles collection: http://guide.meteor.com/code-style.html#collections
To answer your question about how much of the file is exported (i.e. which functions), there's not much you can do about everything being loaded. The bundler needs to read the entire JS file anyway (imagine you exported an object and then changed it further down in the same file– not the best practice, but possible). If you're not using a function though, by all means, don't import it! And you can always split up your methods into seperate files if they get unmanageable.
Regarding your question about only importing bits for certain user roles: always avoid using imports or other types of obfuscation for security. The ideal way to do security on Meteor is to assume ANYTHING is accessible on the client (it pretty much is) and code your server-side code accordingly. That means, if you have an admin area, assume that anyone can access it. You can do checks in server methods and publications for this.userId and do a database lookup there to ensure the user has the correct privileges. Again, the guide has more info about this: http://guide.meteor.com/security.html
A final note about imports/exports: the idea behind them is not to reduce code size, but to provide a graph of what is actually being used (and leaving out the files that aren't) to make hot code reloading faster for a better development experience. They also make for cleaner application code that is easier to understand, because you don't have random magical globals swimming around that could have come from anywhere, and help to keep logically distinct pieces of code separate.
Best of luck :)

Variable dependency in RequireJS

I'm using RequireJS to load my JavaScript modules for a BackboneJS web app, but I'm running into a style issue at the moment.
I have two classes that share a LOT of code, but they both subclass different classes.
TemplateLessonView LessonView
| |
| |
EditorApp <-- these share code --> MainApp
Now to keep things DRY I'd like MainApp to extend EditorApp, but then EditorApp's dependencies are loaded and EditorApp calls some of it's base class' functions by means of this format: this.constructor.__super__.initialize.apply(this);
A solution would be to change EditorApp's dependencies when the module is loaded from MainApp's module (so I would require LessonView but pass it to EditorApp as TemplateLessonView.
Does anyone know of a way to do this, or has another suggestion to accomplish what I'm trying here?
On way to solve this is to create a module that you will import in both class definition...
something like that :
(...require stuff ...)
return {
myfct1 : function(){
},
myfct2 : function(){
}
}
and then you can import the module where you need it, and then call your common code like a library...

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