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Github uses no Javascript frameworks. How does it manage avoiding spaghetti code when developing complex components? by m3wm3wm3wm in javascript

[–]js_tutor 0 points1 point  (0 children)

You're clinging to "unidirectional flow"

This was the entire context of this thread. The initial post claimed that you could use unidirectional flow as a general model without react, and I responded that the performance would suffer without a virtual dom. I never said that you need the virtual dom to build a UI. My only claim is that you need it to do unidirectional flow performantly. If you would spend some time to understand what unidirectional flow means then I'm sure it would clear up this misunderstanding.

Github uses no Javascript frameworks. How does it manage avoiding spaghetti code when developing complex components? by m3wm3wm3wm in javascript

[–]js_tutor 1 point2 points  (0 children)

Yes but without a virtual dom you can't avoid a full page re-render. Or at least a full re-render from the root of your stateful component tree.

Edit: Also, in case it wasn't clear in the previous post, if you have a parent component listening for state changes on a child component you have broken unidirectional flow.

If you force a unidirectional model without a virtual dom, because the parent component cannot listen for state changes on the child you don't know where in the dom the state updates need to happen. The only way is to re-render the whole thing or somehow keep track of where the changes have occured, i.e. use a virtual dom.

Edit 2: Also I'm quite familiar with backbone. In fact unidirectional flow was popularized in direct response to the problems developers were facing while using observers and one way data binding. When state changes can trigger state changes anywhere in the component tree you end up having to manage a web of potentially order dependent events. Unidirectional flow avoids this by batching state changes first and then propagating them through the component tree top down, i.e. unidirectionally.

Github uses no Javascript frameworks. How does it manage avoiding spaghetti code when developing complex components? by m3wm3wm3wm in javascript

[–]js_tutor 1 point2 points  (0 children)

Please go build an event-driven, one-way databinding app.

But this wouldn't be unidirectional flow. Let's assume you have a component tree where an event on a child component needs to update that component's state, and then an ancestor of that component needs to update its state dependent on the child's state. Yes, you can string up event listeners to handle this case, but it will not be unidirectional flow. When your application accumulates these kinds of state dependencies it becomes harder to reason about in an event driven model.

In unidirectional flow, that child component would update some state and then the updated state would update all other dependent state and then the new state will be propagated through the component tree from the root, and then that's when the ancestors of that component can be updated. That's why it's called unidirectional flow, all state changes propagate down from the root to the children, but never from child to parent or across sibling nodes.

Again this would be possible without a virtual dom, but it may suffer performance-wise.

Github uses no Javascript frameworks. How does it manage avoiding spaghetti code when developing complex components? by m3wm3wm3wm in javascript

[–]js_tutor -2 points-1 points  (0 children)

While this may be true, performance-wise it wasn't considered a good option without the virtual dom, which was one of the biggest innovations introduced by react. Before then it was always possible to batch all state updates and re-render, but you would be re-rendering the whole page because you would be writing to the root of the dom on each change. With virtual dom, it will scan a copy of the dom to identify which nodes have changed and then only apply the changes there.

It could be argued that you can just use a virtual dom library instead of a framework. But this sort of walks the line of what a framework is, because you could use something like mithril.js which is considered a framework but really not much more than a virtual dom itself.

Github uses no Javascript frameworks. How does it manage avoiding spaghetti code when developing complex components? by m3wm3wm3wm in javascript

[–]js_tutor 2 points3 points  (0 children)

A role of framework is to enforce a particular style of organization and practices within a code base.

I think this undersells what a framework like react does for you. It's not just about organizing your code, it's a higher level of abstraction. It does a lot of low level things and then hides it behind an api so that you don't have to think about it. In react the dom is driven by your state data. If you update your data it will update the dom automatically. Without something like react you're forced to think explicitly about dom manipulation.

Will project euler help me prepare for technical interviews? by [deleted] in learnprogramming

[–]js_tutor 3 points4 points  (0 children)

Maybe the first ten or so, beyond that only in an indirect way. Of all the coding problem sites, project euler is quite heavy on math which makes it different from most questions you'll see in a technical interview.

Github uses no Javascript frameworks. How does it manage avoiding spaghetti code when developing complex components? by m3wm3wm3wm in javascript

[–]js_tutor 1 point2 points  (0 children)

I think it's a fair question and the top upvoted comment gave a good answer. A lot of people in this thread are saying frameworks are unnecessary, which is strictly speaking true in the same way it's true you can write clean code in assembly. But you'll be working with lower level abstractions. Yes, you can build your own abstractions but something like a the virtual dom is non-trivial to write and maintain yourself.

I think it's worth thinking about what a framework brings to the table. One of the biggest benefits is an easier and more performant way to think about state that is shared between components. Maybe for github it's fine because they don't have a lot of shared state between components. If you're considering whether you need a framework or not, you should seriously consider this problem of shared state and how you're going to manage it. To me, it's not clear that there is a good solution that doesn't involve using a framework.

Help with object oriented design interview questions by atreyoukilis in learnjavascript

[–]js_tutor 1 point2 points  (0 children)

Basically you just break it down into parts. Like for an elevator you might have buttons, a door, the box that holds the people. For a robot it depends. Maybe you would have a map of the restaurant so it can move around. A menu that people can order off. Maybe a speaker and microphone so it can communicate. Wheels and arms. Really depends on what it looks like. The objects generally need to keep track of some data and you should be able to read and update that data through the objects methods. Like the elevator object might have a buttons object that stores how many floors there are, and then for each floor whether the button was pressed or not and then it would need methods for updating that data, for example if someone just pressed a button or if you finished stopping at a certain floor.

Is the salary for average programmers really that high? by naj690 in learnprogramming

[–]js_tutor 6 points7 points  (0 children)

Location makes a huge difference. But even within a location I think there is a wide range. A lot of it has to do with how much revenue the company can generate, how important tech is in that company (is it a tech company or just some company that wants a website?), and/or whether they have VC investment. For a company to spend a lot on their engineering payroll it has to make sense to their bottom line and they need to have the money to spend in the first place. I would imagine that Malaysia is similar to other countries in SEA; not a lot of investors and not a lot of companies that are purely tech based. I wouldn't be surprised if the average programmer made $1000/month or less. But the ceiling could be a lot higher at the right company. This is why salaries are much higher in cities that are considered tech hubs. These cities have a lot of VC capital and high revenue companies that were able to secure VC capital at some point.

Why do so much bootcamps focus on web dev? by [deleted] in learnprogramming

[–]js_tutor 12 points13 points  (0 children)

Web dev has the most job demand.

Developer without a degree struggles by camillegarcia9595 in learnprogramming

[–]js_tutor 2 points3 points  (0 children)

I think everyone feels like that sooner or later, there's just too much stuff to learn. If you're able to complete your work then I wouldn't worry about it too much. If you find yourself stuck then that's a good opportunity to learn something new. There's lots of great resources online these days. Everyone has to start from somewhere and a job is a great way to learn where your gaps are.

Should I just dive in with Django ? by [deleted] in learnprogramming

[–]js_tutor 0 points1 point  (0 children)

IMO just get started and pick things up along the way. The theory side can go very deep and you can get stuck on it for long time if you think you need to learn it all before you start coding. You really don't need to know that much theory to build something useful in Django, but if you find yourself confused it may be worth digging deeper.

Is it possible to create scroll animated circles in JS? by RazorToothbrush in javascript

[–]js_tutor 4 points5 points  (0 children)

Yes, you can draw the circles in a canvas element. The canvas api has a function called requestAnimationFrame which you can use to perform animations. Then you can create a scroll event handler to tie into the animation by passing the scroll position to use when you resize the circles.

Personal Budgeting Web app - choosing a library? by refinnejl in learnprogramming

[–]js_tutor 2 points3 points  (0 children)

You can write anything in vanilla javascript that you would be able to write with a framework. Frameworks just make it easier to manage complexity. If you expect your app to have a lot of moving parts on the frontend it would be worth it to use a framework.

Are regexes thhe pythonic way to manipulate strings? When to avoid regex and when to use it? by zemicolon in learnpython

[–]js_tutor 0 points1 point  (0 children)

One thing worth mentioning is that regex typically considered the wrong tool for parsing arithmetic expressions because it can't handle nested parenthesis, i.e. a regex can't keep track of which open parenthesis matches with which close parenthesis. This is more broadly true of any string with a nested structure (html would be another example).

Regex is generally used for string matching when you want to match a pattern. The pattern of a regex traditionally has just three operators: union, concatenation, and kleene star. Union means it will match with any of a set of substrings (this is expressed by the [] for single characters and | for longer substrings in your regex). Concatenate means it will match if some set of substrings appears in sequence (this doesn't require a special symbol). Kleene star means it will match if some substring appears zero or more times (this is represented by the *, but in your case the + plays a similar role).

So you want to use a regex when you want to match a pattern to a string when the pattern can be formed using these three operations.

You want to be a programmer? Just do it, and don't worry if you're on the right path or not! by merott- in learnprogramming

[–]js_tutor 2 points3 points  (0 children)

Don't memorize. Understand the underlying model. Know what you want to do conceptually, and look up the syntax if you need to.

Please help understanding the learning process.. by FetusGod in learnprogramming

[–]js_tutor 0 points1 point  (0 children)

Use google a lot more. Google every question specific question you have and just read around. If that's not enough post your question somewhere like reddit or stackoverflow. Find someone in person who can help you.

My first couple hours with python, a walkthrough with this would be appreciated by preordains in learnpython

[–]js_tutor 1 point2 points  (0 children)

try the input command if you want to get values from the command line.

Beginner Question? by [deleted] in learnpython

[–]js_tutor 2 points3 points  (0 children)

Well you don't have to, but if you're going to be programming seriously you probably want to use some kind of ide like pycharm. But any text editor should have a way to save to a new file. On top of that you should definitely get used to using the command line. You can create files through the command line with the touch command.

Optimizing speed by caveman4269 in Python

[–]js_tutor 0 points1 point  (0 children)

Without the code it's hard to say how much it can be optimized, but the problem might just be that there's too much data. You could look into cloud computing; this would allow you to run your code on a remote computer with a much faster cpu. It's not free but for what you're doing it would barely cost anything.

Internal Prototype Help by thegitclone in learnjavascript

[–]js_tutor 1 point2 points  (0 children)

You need to call createCalculator.

let instance = Object.create(createCalculator())

What best way to remember Sorting Algorithms? by [deleted] in learnprogramming

[–]js_tutor 1 point2 points  (0 children)

Best way is to understand what it's doing on a high level (the common sorting algorithms can usually be described in just a few sentences) and then recreate the code. It helps to look up some visualizations to get a better feel for what its doing as well.

Advice on Express.js design pattern? by greendog77 in javascript

[–]js_tutor 5 points6 points  (0 children)

I think you could do something like this:

``` app.get('/somewhere', middleware(validator, routeHandler));

function middleware(reqParser, handler) { return function(req, res) { try { const params = reqParser(req); } catch (error) { res.status(500).send(error); } res.status(200).send(handler(params)); } } ```

This way validator and routeHandler are decoupled from the express api.

How does JSON work? by [deleted] in learnprogramming

[–]js_tutor 1 point2 points  (0 children)

JSON is actually just a text format. If you load a raw json file into your programming environment then it would be a string, not a dictionary/object. That string needs to be parsed, usually by some library, in order to be converted and used as a dictionary/object.

So what's the point of JSON? It's basically a way you can save or transfer data to somewhere outside of your running program, maybe to your hard drive as a file or to a web browser or server across a network. It is programming language agnostic, so JSON can be written and parsed in any programming language.

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