Admittedly, I'm new to some of this...
Building a website on a local server. It has a ton of JS function in an external JS file.
Site has a MYSQL DB. (I am still learning this).
As part of my calculations from functions in that external JS file, I want to update and/or read from that DB.
I have been trying to read up on node.js and trying to read up on PHP (still learning both), but I'm not sure if I'm sniffing in the right direction.
Do I somehow invoke functions from node.js from the external JS file? Do I somehow invoke the PHP (in the form of a function, I suppose) from the external JS file?
How does one typically do this?
I have definitely learned that this in the external JS file does not do the trick. First window appears, but second doesn't:
// Activate the node.js library for MYSQL access
alert("got here 1");
var mysql = require('./mysql');
alert("got here 2"); // nope, this never pops up
Higher-level advice might be more useful than detailed in-the-weeds advice...? Still very new to this.
Thank you kindly!
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self-muttering thoughts... I am using the external JS file to hold a bunch of functions that do all kinds of manipulation and conformation to the data that I collect on the front end:
<button class="ButtonOperation" onclick="DataLog(document.getElementById('DataWindow').value,'NE_AssembleOrder')">Log Data</button>
Am I eventually going to discover that I should instead port all of these functions over to a big PHP file instead?
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Okay, took a while before I better understood this. So, this is the answer that would have gotten me moving in the right direction (for any future reference):
The thing to understand is that for this project, you want to manipulate data to and from a database, which means that (at least for now, for the sake of simplicity), the key is to get your data into a package and send it up to the server, and then have a function running on the server take up the yoke from there.
The way to do that (old school), is with a form.
When you SUBMIT a form, all that data on the form is bundled up and sent to the server.
In this instance you have an index.html page, and that page will open a new page for each of the functions you're trying to track. Use JavaScript to pop open the window and then when you include the URL for the window, pop in a Popup_SpecificFunction.php file. (change SpecificFunction as needed)
So far, so good. ;)
Now, in that Popup_SpecificFunction.php, you will collect all your data under a single form. A good ol' HTML form, with a [SUBMIT] button. That very same Popup_SpecificFunction.php file also has a reference in the header, referring to the big main library of PHP functions -- which is a file sitting on the server.
That [SUBMIT] button invokes a ProcessAllThisData function -- which is on the server-side PHP file. In doing this, it sends all the data from the form -- including a lot of data you include in hidden controls -- to the serverside function.
And at that point, you are basically "on the server" with all your data, and then you can just code that function in PHP and manipulate the database and other stuff as needed.
Using the form was the thought-jump you needed, because prior to this, you've generally thought of forms as standalone data, but they can have actions associated with the entire forms.
You can still use JavaScript to do client-side stuff, but here's another thing that can trip a person up:
There is a difference between these two HTML items as far as whether or not you should use them to send data to and from the server, or whether or not you are just going to JavaScript something on that button:
<button></button>
and
<input type="button"></input>
You might have to experiment a bit to figure out which is which.
This was everything you needed to get you moving in the right direction.
Sincerely,
Future Me. :)
I know it's impossible to hide source code but, for example, if I have to link a JavaScript file from my CDN to a web page and I don't want the people to know the location and/or content of this script, is this possible?
For example, to link a script from a website, we use:
<script type="text/javascript" src="http://somedomain.example/scriptxyz.js">
</script>
Now, is possible to hide from the user where the script comes from, or hide the script content and still use it on a web page?
For example, by saving it in my private CDN that needs password to access files, would that work? If not, what would work to get what I want?
Good question with a simple answer: you can't!
JavaScript is a client-side programming language, therefore it works on the client's machine, so you can't actually hide anything from the client.
Obfuscating your code is a good solution, but it's not enough, because, although it is hard, someone could decipher your code and "steal" your script.
There are a few ways of making your code hard to be stolen, but as I said nothing is bullet-proof.
Off the top of my head, one idea is to restrict access to your external js files from outside the page you embed your code in. In that case, if you have
<script type="text/javascript" src="myJs.js"></script>
and someone tries to access the myJs.js file in browser, he shouldn't be granted any access to the script source.
For example, if your page is written in PHP, you can include the script via the include function and let the script decide if it's safe" to return it's source.
In this example, you'll need the external "js" (written in PHP) file myJs.php:
<?php
$URL = $_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
if ($URL != "my-domain.example/my-page.php")
die("/\*sry, no acces rights\*/");
?>
// your obfuscated script goes here
that would be included in your main page my-page.php:
<script type="text/javascript">
<?php include "myJs.php"; ?>;
</script>
This way, only the browser could see the js file contents.
Another interesting idea is that at the end of your script, you delete the contents of your dom script element, so that after the browser evaluates your code, the code disappears:
<script id="erasable" type="text/javascript">
//your code goes here
document.getElementById('erasable').innerHTML = "";
</script>
These are all just simple hacks that cannot, and I can't stress this enough: cannot, fully protect your js code, but they can sure piss off someone who is trying to "steal" your code.
Update:
I recently came across a very interesting article written by Patrick Weid on how to hide your js code, and he reveals a different approach: you can encode your source code into an image! Sure, that's not bullet proof either, but it's another fence that you could build around your code.
The idea behind this approach is that most browsers can use the canvas element to do pixel manipulation on images. And since the canvas pixel is represented by 4 values (rgba), each pixel can have a value in the range of 0-255. That means that you can store a character (actual it's ascii code) in every pixel. The rest of the encoding/decoding is trivial.
The only thing you can do is obfuscate your code to make it more difficult to read. No matter what you do, if you want the javascript to execute in their browser they'll have to have the code.
Just off the top of my head, you could do something like this (if you can create server-side scripts, which it sounds like you can):
Instead of loading the script like normal, send an AJAX request to a PHP page (it could be anything; I just use it myself). Have the PHP locate the file (maybe on a non-public part of the server), open it with file_get_contents, and return (read: echo) the contents as a string.
When this string returns to the JavaScript, have it create a new script tag, populate its innerHTML with the code you just received, and attach the tag to the page. (You might have trouble with this; innerHTML may not be what you need, but you can experiment.)
If you do this a lot, you might even want to set up a PHP page that accepts a GET variable with the script's name, so that you can dynamically grab different scripts using the same PHP. (Maybe you could use POST instead, to make it just a little harder for other people to see what you're doing. I don't know.)
EDIT: I thought you were only trying to hide the location of the script. This obviously wouldn't help much if you're trying to hide the script itself.
Google Closure Compiler, YUI compressor, Minify, /Packer/... etc, are options for compressing/obfuscating your JS codes. But none of them can help you from hiding your code from the users.
Anyone with decent knowledge can easily decode/de-obfuscate your code using tools like JS Beautifier. You name it.
So the answer is, you can always make your code harder to read/decode, but for sure there is no way to hide.
Forget it, this is not doable.
No matter what you try it will not work. All a user needs to do to discover your code and it's location is to look in the net tab in firebug or use fiddler to see what requests are being made.
From my knowledge, this is not possible.
Your browser has to have access to JS files to be able to execute them. If the browser has access, then browser's user also has access.
If you password protect your JS files, then the browser won't be able to access them, defeating the purpose of having JS in the first place.
I think the only way is to put required data on the server and allow only logged-in user to access the data as required (you can also make some calculations server side). This wont protect your javascript code but make it unoperatable without the server side code
I agree with everyone else here: With JS on the client, the cat is out of the bag and there is nothing completely foolproof that can be done.
Having said that; in some cases I do this to put some hurdles in the way of those who want to take a look at the code. This is how the algorithm works (roughly)
The server creates 3 hashed and salted values. One for the current timestamp, and the other two for each of the next 2 seconds. These values are sent over to the client via Ajax to the client as a comma delimited string; from my PHP module. In some cases, I think you can hard-bake these values into a script section of HTML when the page is formed, and delete that script tag once the use of the hashes is over The server is CORS protected and does all the usual SERVER_NAME etc check (which is not much of a protection but at least provides some modicum of resistance to script kiddies).
Also it would be nice, if the the server checks if there was indeed an authenticated user's client doing this
The client then sends the same 3 hashed values back to the server thru an ajax call to fetch the actual JS that I need. The server checks the hashes against the current time stamp there... The three values ensure that the data is being sent within the 3 second window to account for latency between the browser and the server
The server needs to be convinced that one of the hashes is
matched correctly; and if so it would send over the crucial JS back
to the client. This is a simple, crude "One time use Password"
without the need for any database at the back end.
This means, that any hacker has only the 3 second window period since the generation of the first set of hashes to get to the actual JS code.
The entire client code can be inside an IIFE function so some of the variables inside the client are even more harder to read from the Inspector console
This is not any deep solution: A determined hacker can register, get an account and then ask the server to generate the first three hashes; by doing tricks to go around Ajax and CORS; and then make the client perform the second call to get to the actual code -- but it is a reasonable amount of work.
Moreover, if the Salt used by the server is based on the login credentials; the server may be able to detect who is that user who tried to retreive the sensitive JS (The server needs to do some more additional work regarding the behaviour of the user AFTER the sensitive JS was retreived, and block the person if the person, say for example, did not do some other activity which was expected)
An old, crude version of this was done for a hackathon here: http://planwithin.com/demo/tadr.html That wil not work in case the server detects too much latency, and it goes beyond the 3 second window period
As I said in the comment I left on gion_13 answer before (please read), you really can't. Not with javascript.
If you don't want the code to be available client-side (= stealable without great efforts),
my suggestion would be to make use of PHP (ASP,Python,Perl,Ruby,JSP + Java-Servlets) that is processed server-side and only the results of the computation/code execution are served to the user. Or, if you prefer, even Flash or a Java-Applet that let client-side computation/code execution but are compiled and thus harder to reverse-engine (not impossible thus).
Just my 2 cents.
You can also set up a mime type for application/JavaScript to run as PHP, .NET, Java, or whatever language you're using. I've done this for dynamic CSS files in the past.
I know that this is the wrong time to be answering this question but i just thought of something
i know it might be stressful but atleast it might still work
Now the trick is to create a lot of server side encoding scripts, they have to be decodable(for example a script that replaces all vowels with numbers and add the letter 'a' to every consonant so that the word 'bat' becomes ba1ta) then create a script that will randomize between the encoding scripts and create a cookie with the name of the encoding script being used (quick tip: try not to use the actual name of the encoding script for the cookie for example if our cookie is name 'encoding_script_being_used' and the randomizing script chooses an encoding script named MD10 try not to use MD10 as the value of the cookie but 'encoding_script4567656' just to prevent guessing) then after the cookie has been created another script will check for the cookie named 'encoding_script_being_used' and get the value, then it will determine what encoding script is being used.
Now the reason for randomizing between the encoding scripts was that the server side language will randomize which script to use to decode your javascript.js and then create a session or cookie to know which encoding scripts was used
then the server side language will also encode your javascript .js and put it as a cookie
so now let me summarize with an example
PHP randomizes between a list of encoding scripts and encrypts javascript.js then it create a cookie telling the client side language which encoding script was used then client side language decodes the javascript.js cookie(which is obviously encoded)
so people can't steal your code
but i would not advise this because
it is a long process
It is too stressful
use nwjs i think helpful it can compile to bin then you can use it to make win,mac and linux application
This method partially works if you do not want to expose the most sensible part of your algorithm.
Create WebAssembly modules (.wasm), import them, and expose only your JS, etc... workflow. In this way the algorithm is protected since it is extremely difficult to revert assembly code into a more human readable format.
After having produced the wasm module and imported correclty, you can use your code as you normallt do:
<body id="wasm-example">
<script type="module">
import init from "./pkg/glue_code.js";
init().then(() => {
console.log("WASM Loaded");
});
</script>
</body>
My limited experience in web development as a self-taught led me to hit a wall while trying to figure out how to deal with this problem.
I need a form (map_settings.php) where the user should enter some inputs. Those inputs must be saved in a database table (MAPS) and then used to create the final HTML file (e.g. map1.html) for that specific user/inputs.
I know how to deal with using forms and saving submitted data to a database.
What is completely obscure to me is how can I use those inputs to automatically generate the final HTML.
My idea is to have a template HTML (template.html) and each time a user saves new settings via the form, I copy the template and replace some variables inside it with the actual data the user has input in the form.
If this might matter, the variables I need to replace in the template are also JavaScript variables within a <script> tag.
Can anybody help me suggesting one viable way to do this? I am mostly using JavaScript and PHP, without frameworks. I've also red about JavaScript templating engines, but I sincerely did not get if those are useful to me in my case.
Anyway, here is an illustration of what I would need to do, to hopefully clarify better my point.
Creating a static HTML file per user is not the way to go. Instead just have a PHP script like mapdisplay.php or similar.
Make the script so that if you type mapdisplay.php?map=1 in the browser then it will read the map ID, get the relevant settings from the database for the map in question and then generate some HTML to display them - of course you can have most of the HTML ready made like a template, and just use PHP to fill in the details from the database. This idea of getting data on the fly when requested, and plugging it into some HTML is how most web applications work.
If you create a static HTML for each user it quickly becomes unmanageable with a large number of users, plus it's hard to introduce changes or improvements to the template because instead of just updating one script file, you have to back and re-do every existing page. There are other disadvantages to your approach too, but I won't continue here - you get the idea I hope.
If I were you I'll make that in this way:
Don't use template.html
Don't get data from database to new file, but from form
Make database test before make file
To make template use
$template_text = "text...text...html...text...".$php_varible."text...text...html...text";
For other things about php see w3schools
I'm listening to a Ctrl-C event and creating a JSON, I'll need this JSON in a different part of my application where I intend to use the JSON for a custom paste on Ctrl-V; but I don't have any reference here to the previous part, where the copy was done. Not even a global variable (long story).
Basically, these Ctrl-C and Ctrl-V events are supposed to copy and paste complex custom-made HTML elements, with their own events and keyframe animations, from one part of the application to the other. Working with the JSON is the only way to go.
I did some digging and came across questions like this, but they only address the case of putting selected text on the clipboard. I'm looking for something which can put custom content on the clipboard of the system or the browser.
Is there any inbuilt method, or an external utility or plugin, that would help me achieve this?
Thanks.
EDIT: This copy-paste feature will be used on a website by users, not just developers. Therefore, we can't assume anything. Cookies won't work because cookies might be turned off. localstorage or sessionstorage won't work because the application may be open for different projects in different windows; and the user might want to copy from one window and paste into another.
You could look in to cookies here using jQuery:
// You can seriaize the data as JSON, like this:
$.cookie("property-name", JSON.stringify($("#foo").data()));
// Get data from the cookie:
$("#foo").data(JSON.parse($.cookie("property-name")));
you could always use localstorage or sessionstorage depending on the lifetime required. although this may not work in older browsers. and will mean the user cannot paste in content from external sources
I have a typical HTML form, with some fields of various types on it.
What I'm trying to achieve is the following:
Once the form's input fields are filled out with values, a button to be able to save all the filled-out field/value pairs into a local file of some sort that allows me in a future ocassion to...
Automatically fill the very same HTML form by retriving the field/values pairs from said file instead of typing them manually.
Ideally this would have to be achived thru JavaScript, because the webpage that contains the HTML form is served by an embedded system where PHP or other server side scripting is not available.
Is it possible to achive this thru JavaScript (or any other browser-side effort method)? If so, how?
Many thanks.
EDIT: The target environment is a regular user in a regular PC/laptop using any one of the 4 major browsers. It's acceptable to have "Cookies enabled" and "latest browser version installed" as requisites, but external plugins/addins are not.
Later: NullUserException has achived something in this direction. He's been able to read from a local file using JavaScript:
Using a local file as a data source in JavaScript
I think, for your particular site you can store data in local storage. Only your application will be able to access to that data. Also you can encrypt it before storing.
You can refer
diveintohtml5.info/storage to start with.
Happy coding.
Pretty sure you won't be able to save a file locally and then pick it up again.
However there are obviously cookies but there, and this is only in a modern browser, is also LocalStorage that can hold quite a bit of data that can be retrieved by Javascript and jQuery.
This is probably the way I would go but it does depend on your browser version.
question is some what ambiguous please specify what you are trying to do.
i can't tell if you want to do something just for you if so:
https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/