Replace text before other scripts load - javascript

I have piece of code:
<!doctype html>
<html lang="en">
<head>
<script src="main.js"></script>
</head>
<body>
<script src="custom.js?token={{token}}"></script>
</body>
</html>
main.js is my script which replace in body tag {{token}} for value provided from Query.
window.onload = function() {
var link_sid = query.get('link_sid');
document.body.innerHTML = document.body.innerHTML.replace(/{{token}}/g, util.protocol() + '://c.' + util.env() + util.domain() + '/' + link_sid);
}
custom.js?token={{token}} is user content which I can't change.
The problem is that user JS put some HTML code based on my {{token}} value.
So after open page all {{token}} are changed but not inside custom JS cos token was changed after JS was loaded.
How can I replace {{token}} in custom.js query before it loads? It needs to be done in pure JS.
[Updated 1]
I can't move anything from body also can't change. Body is user-provided content.

You need to load your script dynamically. Here is one way to do it by creating script tag and appending it to the page
<!doctype html>
<html lang="en">
<head>
<script>
var script = document.createElement("script")
script.type = "text/javascript";
script.src = "custom.js?token=" + "your_token"
document.getElementsByTagName("head")[0].appendChild(script);
</script>
</head>
<body>
</body>
</html>

I can see the way you are passing {{token}} to custom.js is a hacky way. I can suggest you to change the way it should be like this:
Since main.js is your script, you can try to assign the {{token}} to a global value, example:
Inside main.js:
window.TOKEN = util.protocol() + '://c.' + util.env() + util.domain() + '/' + link_sid`;
In the html will still be the same, except you don't need to add the {{token}} string:
Then inside custom.js, you can use window.TOKEN to do whatever you want with it.
If the window.TOKEN is evaluated asynchronously, you will also need a callback function from main.js to tell custom.js when the token is ready, then it can start using it, example:
When TOKEN have to be asynchronous:
In main.js:
var TOKEN = util.protocol() + '://c.' + util.env() + util.domain() + '/' + link_sid`;
typeof window.tokenReady === 'function' && window.tokenReady(token); // make sure it's a function before calling it
In custom.js:
window.tokenReady = function (token) {
// Do something with token
}

Related

JavaScript function only works after page reload

I know this has been asked a lot on here, but all the answers work only with jQuery and I need a solution without it.
So after I do something, my Servlet leads me to a JSP page. My JS function should populate a drop down list when the page is loaded. It only works properly when the page is refreshed tho.
As I understand this is happening because I want to populate, using innerHTML and the JS function gets called faster then my HTML page.
I also get this error in my Browser:
Uncaught TypeError: Cannot read property 'innerHTML' of null
at XMLHttpRequest.xmlHttpRequest.onreadystatechange
I had a soulution for debugging but I can't leave it in there. What I did was, every time I opened that page I automatically refreshed the whole page. But my browser asked me every time if I wanted to do this. So that is not a solution that's pretty to say the least.
Is there something I could do to prevent this?
Edit:
document.addEventListener("DOMContentLoaded", pupulateDropDown);
function pupulateDropDown() {
var servletURL = "./KategorienHolen"
let xmlHttpRequest = new XMLHttpRequest();
xmlHttpRequest.onreadystatechange = function () {
if (xmlHttpRequest.readyState === 4 && xmlHttpRequest.status === 200) {
console.log(xmlHttpRequest.responseText);
let katGetter = JSON.parse(xmlHttpRequest.responseText);
JSON.stringify(katGetter);
var i;
for(i = 0; i <= katGetter.length -1; i++){
console.log(katGetter[i].id);
console.log(katGetter[i].kategorie);
console.log(katGetter[i].oberkategorie);
if (katGetter[i].oberkategorie === "B") {
document.getElementById("BKat").innerHTML += "" + katGetter[i].kategorie + "</br>";
} else if (katGetter[i].oberkategorie === "S") {
document.getElementById("SKat").innerHTML += "" + katGetter[i].kategorie + "</br>";
} else if (katGetter[i].oberkategorie ==="A") {
document.getElementById("ACat").innerHTML += "" + katGetter[i].kategorie + "</br>";
}
// document.getElementsByClassName("innerDiv").innerHTML = "" + katGetter.kategorie + "";
// document.getElementById("test123").innerHTML = "" + katGetter.kategorie + "";
}
}
};
xmlHttpRequest.open("GET", servletURL, true);
xmlHttpRequest.send();
}
It can depend on how + when you're executing the code.
<html>
<head>
<title>In Head Not Working</title>
<!-- WILL NOT WORK -->
<!--<script>
const p = document.querySelector('p');
p.innerHTML = 'Replaced!';
</script>-->
</head>
<body>
<p>Replace This</p>
<!-- Will work because the page has finished loading and this is the last thing to load on the page so it can find other elements -->
<script>
const p = document.querySelector('p');
p.innerHTML = 'Replaced!';
</script>
</body>
</html>
Additionally you could add an Event handler so when the window is fully loaded, you can then find the DOM element.
<html>
<head>
<title>In Head Working</title>
<script>
window.addEventListener('load', function () {
const p = document.querySelector('p');
p.innerHTML = 'Replaced!';
});
</script>
</head>
<body>
<p>Replace This</p>
</body>
</html>
Define your function and add an onload event to body:
<body onload="pupulateDropDown()">
<!-- ... -->
</body>
Script needs to be loaded again, I tried many options but <iframe/> works better in my case. You may try to npm import for library related to your script or you can use the following code.
<iframe
srcDoc={`
<!doctype html>
<html>
<head>
<style>[Style (If you want to)]</style>
</head>
<body>
<div>
[Your data]
<script type="text/javascript" src="[Script source]"></script>
</div>
</body>
</html>
`}
/>
Inside srcDoc, it's similar to normal HTML code.
You can load data by using ${[Your Data]} inside srcDoc.
It should work :
document.addEventListener("DOMContentLoaded", function(){
//....
});
You should be using the DOMContentLoaded event to run your code only when the document has been completely loaded and all elements have been parsed.
window.addEventListener("DOMContentLoaded", function(){
//your code here
});
Alternatively, place your script tag right before the ending body tag.
<body>
<!--body content...-->
<script>
//your code here
</script>
</body>

Scrape html with js

I'm trying to get the html of www.soccerway.com. In particular this:
that have the label-wrapper class I also tried with: select.nav-select but I can't get any content. What I did is:
1) Created a php filed called grabber.php, this file have this code:
<?php echo file_get_contents($_GET['url']); ?>
2) Created a index.html file with this content:
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<meta charset=utf-8 />
<title>test</title>
</head>
<body>
<div id="response"></div>
</body>
<script>
$(function(){
var contentURI= 'http://soccerway.com';
$('#response').load('grabber.php?url='+ encodeURIComponent(contentURI) + ' #label-wrapper');
});
var LI = document.querySelectorAll(".list li");
var result = {};
for(var i=0; i<LI.length; i++){
var el = LI[i];
var elData = el.dataset.value;
if(elData) result[el.innerHTML] = elData; // Only if element has data-value attr
}
console.log( result );
</script>
</html>
in the div there is no content grabbed, I tested my js code for get all the link and working but I've inserted the html page manually.
I see a couple issues here.
var contentURI= 'http:/soccerway.com #label-wrapper';
You're missing the second slash in http://, and you're passing a URL with a space and an ID to file_get_contents. You'll want this instead:
var contentURI = 'http://soccerway.com/';
and then you'll need to parse out the item you're interested in from the resulting HTML.
The #label-wrapper needs to be in the jQuery load() call, not the file_get_contents, and the contentURI variable needs to be properly escaped with encodeURIComponent:
$('#response').load('grabber.php?url='+ encodeURIComponent(contentURI) + ' #label-wrapper');
Your code also contains a massive vulnerability that's potentially very dangerous, as it allows anyone to access grabber.php with a url value that's a file location on your server. This could compromise your database password or other sensitive data on the server.

How to remove <script> tags from an HTML page using C#?

<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
if (window.self === window.top) { $.getScript("Wing.js"); }
</script>
</head>
</html>
Is there a way in C# to modify the above HTML file and convert it into this format:
<html>
<head>
</head>
</html>
Basically my goal is to remove all the JavaScript from the HTML page. I don't know what is be the best way to modify the HTML files. I want to do it programmatically as there are hundreds of files which need to be modified.
It can be done using regex:
Regex rRemScript = new Regex(#"<script[^>]*>[\s\S]*?</script>");
output = rRemScript.Replace(input, "");
May be worth a look: HTML Agility Pack
Edit: specific working code
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
string sampleHtml =
"<html>" +
"<head>" +
"<script type=\"text/javascript\" src=\"jquery.js\"></script>" +
"<script type=\"text/javascript\">" +
"if (window.self === window.top) { $.getScript(\"Wing.js\"); }" +
"</script>" +
"</head>" +
"</html>";
MemoryStream ms = new MemoryStream(Encoding.ASCII.GetBytes(sampleHtml));
doc.Load(ms);
List<HtmlNode> nodes = new List<HtmlNode>(doc.DocumentNode.Descendants("head"));
int childNodeCount = nodes[0].ChildNodes.Count;
for (int i = 0; i < childNodeCount; i++)
nodes[0].ChildNodes.Remove(0);
Console.WriteLine(doc.DocumentNode.OuterHtml);
I think as others have said, HtmlAgility pack is the best route. I've used this to scrape and remove loads of hard to corner cases. However, if a simple regex is your goal, then maybe you could try <script(.+?)*</script>. This will remove nasty nested javascript as well as normal stuff, i.e the type referred to in the link (Regular Expression for Extracting Script Tags):
<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
if (window.self === window.top) { $.getScript("Wing.js"); }
</script>
<script> // nested horror
var s = "<script></script>";
</script>
</head>
</html>
usage:
Regex regxScriptRemoval = new Regex(#"<script(.+?)*</script>");
var newHtml = regxScriptRemoval.Replace(oldHtml, "");
return newHtml; // etc etc
This may seem like a strange solution.
If you don't want to use any third party library to do it and don't need to actually remove the script code, just kind of disable it, you could do this:
html = Regex.Replace(html , #"<script[^>]*>", "<!--");
html = Regex.Replace(html , #"<\/script>", "-->");
This creates an HTML comment out of script tags.
using regex:
string result = Regex.Replace(
input,
#"</?(?i:script|embed|object|frameset|frame|iframe|meta|link|style)(.|\n|\s)*?>",
string.Empty,
RegexOptions.Singleline | RegexOptions.IgnoreCase
);

Get content inside script as text

I would like to print the content of a script tag is that possible with jquery?
index.html
<script type="text/javascript">
function sendRequest(uri, handler)
{
}
</script>
Code
alert($("script")[0].???);
result
function sendRequest(uri, handler)
{
}
Just give your script tag an id:
<div></div>
<script id='script' type='text/javascript'>
$('div').html($('#script').html());
</script>
​
http://jsfiddle.net/UBw44/
You can use native Javascript to do this!
This will print the content of the first script in the document:
alert(document.getElementsByTagName("script")[0].innerHTML);
This will print the content of the script that has the id => "myscript":
alert(document.getElementById("myscript").innerHTML);
Try this:
console.log(($("script")[0]).innerHTML);
You may use document.getElementsByTagName("script") to get an HTMLCollection with all scripts, then iterate it to obtain the text of each script. Obviously you can get text only for local javascript. For external script (src=) you must use an ajax call to get the text.
Using jQuery something like this:
var scripts=document.getElementsByTagName("script");
for(var i=0; i<scripts.length; i++){
script_text=scripts[i].text;
if(script_text.trim()!==""){ // local script text
// so something with script_text ...
}
else{ // external script get with src=...
$.when($.get(scripts[i].src))
.done(function(script_text) {
// so something with script_text ...
});
}
}
The proper way to get access to current script is document.scripts (which is array like HTMLCollection), the last element is always current script because they are processed and added to that list in order of parsing and executing.
var len = document.scripts.length;
console.log(document.scripts[len - 1].innerHTML);
The only caveat is that you can't use any setTimeout or event handler that will delay the code execution (because next script in html can be parsed and added when your code will execute).
EDIT: Right now the proper way is to use document.currentScript. The only reason not to use this solution is IE. If you're force to support this browser use original solution.
Printing internal script:
var isIE = !document.currentScript;
function renderPRE( script, codeScriptName ){
if (isIE) return;
var jsCode = script.innerHTML.trim();
// escape angled brackets between two _ESCAPE_START_ and _ESCAPE_END_ comments
let textsToEscape = jsCode.match(new RegExp("// _ESCAPE_START_([^]*?)// _ESCAPE_END_", 'mg'));
if (textsToEscape) {
textsToEscape.forEach(textToEscape => {
jsCode = jsCode.replace(textToEscape, textToEscape.replace(/</g, "&lt")
.replace(/>/g, "&gt")
.replace("// _ESCAPE_START_", "")
.replace("// _ESCAPE_END_", "")
.trim());
});
}
script.insertAdjacentHTML('afterend', "<pre class='language-js'><code>" + jsCode + "</code></pre>");
}
<script>
// print this script:
let localScript = document.currentScript;
setTimeout(function(){
renderPRE(localScript)
}, 1000);
</script>
Printing external script using XHR (AJAX):
var src = "https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js";
// Exmaple from:
// https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/Using_XMLHttpRequest
function reqListener(){
console.log( this.responseText );
}
var oReq = new XMLHttpRequest();
oReq.addEventListener("load", reqListener);
oReq.open("GET", src);
oReq.send();
*DEPRECATED*: Without XHR (AKA Ajax)
If you want to print the contents of an external script (file must reside on the same domain), then it's possible to use a <link> tag with the rel="import" attribute and then place the script's source in the href attribute. Here's a working example for this site:
<!DOCTYPE html>
<html lang="en">
<head>
...
<link rel="import" href="autobiographical-number.js">
...
</head>
<body>
<script>
var importedScriptElm = document.querySelector('link[rel="import"]'),
scriptText = scriptText.import.body.innerHTML;
document.currentScript.insertAdjacentHTML('afterend', "<pre>" + scriptText + "</pre>");
</script>
</body>
</html>
This is still experimental technology, part of web-components. read more on MDN

how can you determine location of <script> tag from inside said tag?

I am trying to figure out the location of the script tag the current javascript is running in. What is really going on is that I need to determine from inside a src'd, dynamically inserted javascript file where it is located in the DOM. These are dynamically generated tags; code snippet:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>where am i?</title>
<script type="text/javascript" charset="utf-8">
function byId(id) {
return document.getElementById(id);
}
function create_script(el, code) {
var script = document.createElement("script");
script.type = "text/javascript";
script.text = code;
el.appendChild(script);
}
</script>
</head>
<body>
<div id="find_me_please"></div>
<script>
create_script(byId("find_me_please"), "alert('where is this code located?');");
</script>
</body>
</html>
You could give the script an id tag, like this dude does...
You can use document.write to create a dummy DOM object and use parentNode to escape out. For example:
<script>
(function(r) {
document.write('<span id="'+r+'"></span>');
window.setTimeout(function() {
var here_i_am = document.getElementById(r).parentNode;
... continue processing here ...
});
})('id_' + (Math.random()+'').replace('.','_'));
</script>
This assumes you don't actually have control of the <script> tag itself, such as when it's inside a <script src="where_am_i.js"></script> - if you do have control of the <script> tag, simply put an ID on it, as in:
<script id="here_i_am">...</script>
If you are just running this on page load, this works
<script>
var allScripts = document.getElementsByTagName('script');
var thisScript = allScripts[allScripts.length];
alert(thisScript);
</script>

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