Develop Reference

Javascript to read Text File to Array without a Webserver or external libraries local on Windows PC

I have an HTML file with JavaScript that I am running without any Webserver/host so I am just opening the file in a browser local to my windows PC. In that HTML file I would like to be able to read a text file in the same folder as the html file. That file will contain data in rows and columns separated with tabs. i.e
1 a
2 b
3 c
I want to keep this as simple as possible so all I have to do is share the HTML and Text file to others so the can open it up local to their computer without any webserver/host and without having to also copy of external libraries like node.js or jquery.
I have searched and tested everything I can find but either I need to reference an external library or I have to run it in a webserver or I need to click a button to load the file through the browser, none of what I want.
Does native JavaScript support the function to read a text file and save it to an array? If so, any code direction would be great.

https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest
XMLHttpRequest() exists in native JavaScript, I think it will help you.
You also can send a request to the file. Or use library: axios.js because when you use XMLHttpRequest() you lose many time to write code which just get content from file, with axios I got file content with one line: `axios.get('file.txt').then(result => console.log(result.data));
To connect Axios: <script src="https://unpkg.com/axios#0.18.0/dist/axios.min.js"></script>
You can read official documentation about axios.js and XMLHttpRequest() in the net.

python javascript scrape automatically

Python novice here.
I am trying to scrape company information from the Dutch Transparency Benchmark website for a number of different companies, but I'm at a loss as to how to make it work. I've tried
pd.read_html(https://www.transparantiebenchmark.nl/en/scores-0#/survey/4/company/793)
and
requests.get("https://www.transparantiebenchmark.nl/en/scores-0#/survey/4/company/793")
and then working from there. However, it seems like the data is dynamically generated/queried, and thus not actually contained in the html source code these methods retrieve.
If I go to my browser's developer tools and copy the "final" html as shown there in the "Elements" tab, the whole information is in there. But as I'd like to repeat the process for several of the companies, is there any way to automate it?
Alternatively, if there's no direct way to obtain the info from the html, there might be a second possibility. The site allows to download the information as an Excel-file for each individual company. Is it possible to somehow automatically "click" the download button and save the file somewhere? Then I might be able to loop over all the companies I need.
Please excuse if this question is poorly worded, and thank you very much in advance
Tusen takk!
Edit: I have also tried it using BeautifulSoup, as #pmkroeker suggested. But I'm not really sore how to make it work so that it first runs all the javascript so the site actually contains the data.

I think you will either want use a library to render the page. This answer seems to apply to python. I will also copy the code from that answer for completeness.
You can pip install selenium from a command line, and then run something like:
from selenium import webdriver
from urllib2 import urlopen
url = 'http://www.google.com'
file_name = 'C:/Users/Desktop/test.txt'
conn = urlopen(url)
data = conn.read()
conn.close()
file = open(file_name,'wt')
file.write(data)
file.close()
browser = webdriver.Firefox()
browser.get('file:///'+file_name)
html = browser.page_source
browser.quit()
I think you could probably skip the file write and just pass it to that browser.get call, but I'll leave that to you to find out.
The other thing you can do is look for the ajax calls in a browser developer tool. i.e. when using chrome the 3 dots -> more tools -> developer tools or press something like F12. Then look at the network tab. There will be various requests. You will want to click one, click the Preview tab, and then go through each until you find a response that looks like json data. You are effectively look for their API calls that they used to get the data to generate things. Once you find one, click the Headers tab and you will see a Request URL.
i.e. this https://sa-tb.nl/api/widget/chart/survey/4/sector/38 has lots of data
The problem here is it may or may not be repeatable (API may change, id's may change). You may have a similar problem with just HTML scraping as the HTML could change just as easily.

How to link javascript in html

I am creating browser based video editing tool. I want a user to first download a ~70mb javascript file and store it somewhere on his computer. I want to link that file when my website is opened. How can I achieve that.
EDIT
What i meant is that there are various files like js1.js,js2.js... all sums upto 70mb . So i will offer a zip folder to download and only link js1 or js2 file etc depending on the effects user wish to apply

i am sorry to inform you but i think there is something really wrong with what you are trying to do.
A "solution" would be to just cache the javascript on the user's browser so any subsequent requests parse the cache instead of requesting the resource again from the server.
You should know however that if you are in need to download ~70mb of a javascript file you are doing something wrong. I have a whole web app project that when published the total size is around 60mb, all files required to properly run included, and its a damn big codebase in there.
I find it very hard to believe there is ever a need for a single javascript file to be that big, in any case maybe a simple caching should do the trick

That is actually done automatically. Once you add a <script> tag with a link to a local js file (also stored on the server) the file is loaded automatically.
See HTML <script> src Attribute for more information on that.
You can only reference to js files on the server. Files on the server could look like this:
index.html
somefancyjsfile.js
You can then reference from inside your html file to the js file via the <script> tag.
I'm not sure though if the size is not a bit too much...

<!DOCTYPE html> in JS file

I am referencing two JS files in my map.HTML header. Chrome console gives
Uncaught SyntaxError: Unexpected token <
Here is why I'm confused. When I click on the Chrome Console error message, it takes me to the Sources tab. Under Sources, it puts me on the relative JS tab, and shows code starting with < !DOCTYPE html> then continues with a ton of code that is not in my map.html file or JS file. Presumably this is generated when the JS is read?
The two JS files are:
https://github.com/socib/Leaflet.TimeDimension/tree/master/dist
https://github.com/calvinmetcalf/leaflet-ajax/tree/gh-pages/dist
I am opening map.HTML locally with Chrome using a simple python server using a batch file (python.exe -m http.server).
I am sure this is very basic, but it's confusing me because I reference plenty of other JS files both online and locally and I don't get this error.
Thanks

If you try https://github.com/socib/Leaflet.TimeDimension/blob/master/dist/leaflet.timedimension.min.js in your browser, you will get an HTML page.
If you try https://raw.githubusercontent.com/socib/Leaflet.TimeDimension/master/dist/leaflet.timedimension.min.js you will get what seams a source javascript file. But your browser may also consider it text/html, because that's what github sends in content-type header.
You can use third party sites which will serve files with appropriate content-type header, (example: https://rawgit.com/socib/Leaflet.TimeDimension/master/dist/leaflet.timedimension.min.js ).

In the future, try to do more research before posting here, otherwise a lot of people are going to downvote your questions, and even insult you.
A simple Google search for the differences between html and javascript may be a good start. The first step would be to remove those doctype lines. They mean nothing in Javascript. Just like the word granola has no meaning in Japanese. Different languages.
However, looking at your code, I don't see any DOCTYPE text in your javascript. In order to really debug this, you're going to want to open your webpage (html) in a browser (I recommend Chrome) and press F12 to open the developer tools. Go to the console and trace the error back through all of the files to find the origin.
In order to check and make sure that you're trying to pull javascript files and not html, take all the src urls you're using and paste them in a browser. If you land on a webpage, that url will serve up html, not javascript like you want. If you get a wall of text, you're probably referencing it correctly.
Correct: https://api.mapbox.com/mapbox.js/v3.0.1/mapbox.js
Incorrect: https://github.com/socib/Leaflet.TimeDimension/blob/master/dist/leaflet.timedimension.min.js
Hopefully this helps before this question gets deleted or put on hold. Also notice that people are going to downvote me for actually answering and trying to help.

You can't directly reference code stored in a github repo like you're trying to.
The URLs you're listing aren't javascript files; they're github webpages. That's why they contain HTML doctypes and code you don't recognize -- it's the github website code.
You can get the URL for the actual javascript files by clicking the "raw" button at the top of any of those pages (after selecting a specific individual file -- the urls you gave were for directories, not individual files.) For example:
This is an HTML file: https://github.com/socib/Leaflet.TimeDimension/blob/master/dist/leaflet.timedimension.min.js
This is the raw javascript:
https://raw.githubusercontent.com/socib/Leaflet.TimeDimension/master/dist/leaflet.timedimension.min.js
(That said, I don't believe it's a good idea to treat github like a CDN; usually you would use that purely as a repository and host the actual files in use elsewhere.)

Xml to js code problem

So i'm very new to xml to javascript so i thought I would learn from w3schools, but this site
http://www.w3schools.com/xml/xml_to_html.asp shows an example that I can't mimic locally. I copy/pasted the .js and downloaded the xml but I just get a blank screen!
It's working in there try it yourself but not for me? Do I need it on a server or something?

Yes, that code retrieves the XML data from a web server using AJAX. Since you don't have a server running locally, you can change the URL to point directly to the w3school's version:
xmlhttp.open("GET","http://www.w3schools.com/xml/cd_catalog.xml",false);
Alternatively, play around on their online version ;)

well i guess you have to add the example xml (cd_catalog.xml) to your file system. and you definitively have to access the html file on a server (apache i.e.)

First, ensure that both HTML file (with the Javascript block in it) and XML file are placed in the same directory.
Next, you probably need to place those files under your local web-server and open the HTML like this:
http://[local server host]/ajax.html
instead of opening the file directly from e.g. Windows Explorer:
C:\[path to the file]\ajax.html
For the latter case you'll get an "Access is denied" error.
-- Pavel

Are you running this under a web server or just creating a couple of text files and loading them in your browser?
The "GET" request this relies upon could possibly be failing.
Use Apache or another similar HTTP server and run the example as if it were hosted on the web.