What are ways to optimize scripts on js? [closed] - javascript

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I noticed, that JS scripts consum a lot of RAM. Particularly, client side socket.io + node.js.
What are ways to optimize scripts on js?
What to look for in the first time and what do standards exist?

You can use some compressor to minification, sometimes I use the grunt properties or https://github.com/mishoo/UglifyJS, or you can do it online here http://jscompress.com
If you have to many files.js to import, you can use requireJs to manage it. http://requirejs.org/

The answer is: you do not need to optimize your scripts, at least not until you have a clear, overriding reason to do so. JS scripts consume as much memory as they consume. The engine manages memory and garbage collects. There is nothing specific you can do to reduce memory consumption other than processing less data, or using fewer libraries. 138MB is not a horribly large footprint, why does that bother you? If you decide that you really have nothing better to worry about than memory usage, then run a profile using your favorite browser devtools. However, if the usage is in someone else's code, and not your own, then there's not really anything you can do except, as I said, get rid of their code and do without it, or replace it with something else.
Not clear what you intend to mean by "what do standards exist". What kind of standards do you refer to? Do you mean best practices? Best practices, as I said, are not to worry about this, unless you are a library author and are trying to optimize your own library, OR, if you suspect a memory leak, which does occur but less frequently than one might think.

Add the scripts to bottom of the html content or can load the script asynchronously.

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Is there a standard way of packaging a Javascript GUI control? [closed]

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Is there a standard way (or ways) of packaging a Javascript GUI control such that it is easy for others to use and evaluate?
For example - should classes be named a certain way, should certain methods always be implemented?
Is a raw Javascript GUI control easy to use, or should it have a wrapper to make it usable in a framework? Currently, the code is not written for any framework.
Some background: I am a long time C# (WinForms) developer. To learn Javascript/HTML5, I ported one of my C# GUI projects, a spiral-shaped slider/track-bar, to Javascript and implemented a test harness using a HTML page. My plan is to use JSDoc to generate documentation once the classes/methods are stable.
Thanks in advance for any guidance.
There are a few best practices:
Use as few dependencies as possible.
Dependencies increase the package size and add the possibility that someone up the chain will insert a vulnerability. One dependency may be including a dozen more.
Don't put things in the global scope.
You can't trust other modules not to collide with you. If you must, pick a unique name.
Set "use-strict".
Use strict forces the browser to use more precise interpretation of your code. It can reduce errors and boost performance.
Don't eval.
While not necessarily evil, it's dangerous and often is a shortcut to doing something right.
As with all best practices, there are cases to ignore each of these.
There are some common patterns that js elements use when attaching to a page. Most typical is for an element that most closely matches the behavior is added to the document with a class that the script recognizes. For example <input type="number" class="praise-helix"></input>. HTML5 also supports custom data attributes, meaning that this is valid <input type="number" data-helix></input>.

Where to put css and javascript [closed]

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If I understand Google encourages to put the css and javascript in the same page that the html. Internal css but not inline. On the other side, all the manuals and tutorials I have read say that I should use an external document.
Where should I put the css and javascript?
Note: in the design o my page there it makes no difference to use the css and javascript of the "above the folder" internal and the rest external. 90% or more of the css and javascript is for the content above the folder. In my case, it makes no sense make a distinction.
https://developers.google.com/speed/pagespeed/insights/
Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles
https://developers.google.com/web/tools/lighthouse/audits/critical-request-chains
There is marginal performance improvement in combining html, css, and javascript in a single document. This theoretical performance boost is outweighed by the many complicating factors that come from trying to do this. You might be saving 20-40ms by combining documents, which is generally not something the end user can detect. You will find more important performance improvements in many other ways.
Merging documents, when done at all, should be acccomplished by using a server-side assembly process so that your code can be well partitioned and well maintained. An example of this is webpack.
But again, unless there is some specialized use case that makes this important, it is not standard practice.

Similar and simplified examples (newbie questions) [closed]

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I'm currently studying about web development, I still don't know about jquery, but I've a little knowledge about javascript, html and css (basic).
I've been looking at some examples in github to improve my skills, and I've found this content;
https://github.com/stewilondanga/editables
I perfectly understand the theory, but I do not know how to put it into practice, I would like for any similar examples (simplified alternatives) and how to convert the exported code generated by javascript into a html5 table?
Any example would be appreciated! thanks for your attention!
First of all, jQuery does not generate code. It's a framework, you load it into a web page, and then you can use it from within Javascript code in that page.
I suggest you start by looking at the source of https://stewilondanga.github.io/editables/, if an editable tables is what you need. There are more general frameworks to do this, e.g. Aloha
To try it yourself, I'd suggest you bite the bullet equip yourself with some kind of web server, be it on a server somewhere, or on your local machine, so you can easily try out things like this, copy the sources, alter the code etc.., and quickly hit reload on your browser.
While it may seem easier to run a local server and point your browser at http://localhost/something, IMHO it also takes more tinkering to get browsers to embrace that fully. You don't need the extra grief while already learning all those new concepts. If you want to tackle this seriously, consider getting a hosting service or small VPS somewhere. If you don't know how to do that, get help for that first, but get it out of the way. It'll save you much grief.

Should I use Lua? [closed]

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I am going to work on my new project where client has demanded to use 'Lua' if possible, I have never used it before and by searching on it I found it is fast compare to javascript and getting popular nowadays.
As I am very confused I had never use it before so I want to know something
Is it really better(in terms of performance and use) then javascript?
Will I get enough resources(because I don't want to move over after starting development due to lack of resources or it becomes hard to me develop)?
Will it needed anything other than C compiler to run?
Please guys it is really important to know about such thing before starting. Any help will be appreciated.
I'm assuming you're writing a standalone application in C or C++, and you're looking for a language to enable people to extend that application by embedding another language. That's pretty much Lua's territory.
Lua's strong point is that it's very easy to embed in your (C) application. It compiles quickly, it's tiny, licensing is liberal and using C functions from Lua is relatively easy. Standard Lua has enough performance for most things you'd use a language like this for; if you need more raw speed you could look into LuaJIT, the JIT-compiler for Lua.
As for your questions:
LuaJIT will probably be pretty much as fast as you can get for a dynamic language. Lua is used in games (Sim City, Far Cry, World of Warcraft), where performance is very important.
If by 'resources' you mean documentation: sure. Lua is a very simple language, much simpler than JavaScript; the manual should help you get started with the language itself, the wiki is tasty for tips about the embedding process. This article has an example you can copy/paste.
Lua pretty much runs everywhere a C program will run. It doesn't even need an operating system, and it doesn't depend on anything at runtime if you bundle it correctly.
Embedding a full JavaScript environment in your application, and interfacing your application to the JS environment, can be a lot of work (even though Google's V8 engine has some functionality to help you; see here).

Do you have any security concerns when it comes to JQuery plugins? [closed]

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I am curious as to what, if any, security concerns other develpers have in regards to the use of JQuery plugins. I have seen very little talk about security where JQuery is concerned. Is it really a non issue?
Appreciate your thoughts!
Personally I am comfortable enough with Javascript to be able to swiff through the plugin code and understand possible misbehavior.
What I look for is the most relevant security issue with javascript, cross-domain communication, which is usually done with the creation of iframes, script/img tags etc..
Most of the times though, I trust the community, for example if it's up on http://plugins.jquery.com/ it is usually a trusted source.
jQuery can't do anything that javascript itself can't do, so all the same security standards apply. Basically - never rely on it for security. Always validate all inputs on the server side.
The best way to think of it is that from a security perspective, the client-side javascript is not actually a part of your application. Your application consists of all the possible http calls to your server. For good security, assume that hackers won't even be using a browser - they'll be making http requests directly to your server. Make sure that you aren't exposing any vulnerabilities in your http endpoints, and you should be ok.
note: I made the assumption in this reply that you're talking about data and system security. User security (preventing your users from being phished, etc) is another kettle of fish, but I'm not sure it has to do with jQuery any more than javascript in general.
The most popular ones are used all over the web on major web sites. If there is a security concern, someone else has probably already noted it. Also, a lot of the most-used jQuery plug-ins come from the same developers who are very active in the community, so it's fairly safe to trust them. (Jörn Zaefferer, the guy who did the validation plug-in, comes to mind)
Granted, it's a good idea to always test and always be skeptical, but at some point it becomes cost inefficient to worry too much.

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