How to find a function in javascript files - javascript

I have many javascript files referenced in an HTML file. There is a call to function X. How can I find where X is?
Additional description:
It's not a local site and I don't have js, but I can download js and search the files. I'd like to use some method like Firebug, etc.

Two methods. First, you could grep for it in your files, if you're on a Linux machine. That's probably quicker.
The other way you could do it easily is with FireBug (http://getfirebug.com). Once the page is loaded, open the console and go to the Script tag. Put the function name in the search bar and click "Next" until you find where the function is defined, and it will tell you which file it's in in the upper left hand corner.

Search the files for X function name. Also as previous poster said - firebug for Firefox is your special friend when developing for the web.

I would hope that if you have multiple external JS files that you have a reason for it and the functions you create in them have names that somewhat represent what they do in which you can get an idea of which file it is in.
To directly answer, open one up and use the find feature in your IDE.

Related

How to access one JS file from a function inside a JS file

So, I am making a "ModReady" version of my JavaScript game where you can easily mod a game. The point is to click a button inside a ModReady version of a game, type the filepath of the mod you want to run, and the JavaScript executes it.
I have a problem though. I don't think you can run a separate .js file from inside a function.
Is this possible to do?
Depends on where the game is relative to the mod authors file. The short answer is yes, but you have to be a little cunning if the mods script doesn't exist in the same place as yours.
The safest and easiest method would be to offer a version of the code base which others can download and mod themselves.
Alternatively theres several methods of running code cross browser, i wouldn't advise letting other peoples code reside on your server.
The simplest method would be similar to the way code pen or JSfiddle work, you have a text box which the mod adds the code to. Then either run your game in an iframe with the text box contents included in a script element, or store the string in a HTML 5 local storage element, load the game page querying the local storage and add the local storage string to a new script element.

tracking a javascript found in pagesource

ive tried everything i cud to figure this out, but i cannot track a piece of javascript in a webpage
so, just to give you some context even though my problem is not related to just this scenario. it depends on a much bigger spectrum.
Anyway, im developing on sugarCRM and im trying to edit the default onclick behavior of a slot in calendar module (you dont need to understand this to help me, so please keep reading). when i click on a slot, a modal dialog window opens that lets me log a meeting or a call.
So i tracked down the javascript behind this. ive used firebug and chrome, and they both give a list of all the JS files that are being used on a given webpage
for example i search for "SUGAR.collection" and firebug tells me its located in a file named "sugar_field_grp.js?v=FVh1Z-v5nA6bYov7-aFFqQ" i can see this piece of code resides in sugar_field_grp.js,
but the code im trying to change resides in "index.php?module=Calendar&action=index&parentTab=Activities", firebug actually tells me this is the file that has the javascript i want to change.
I can also right click view page source and i can see that piece of code inside the script tag. so considering this piece of code doesnt reside in a JS file, i cannot change it, its generated at runtime (i think) but there must be some source, there must be a file thats telling sugarCRM to generate this code
tl;dr how to track down a piece of javascript code that resides on pagesource and theres no JS file specified by firebug or chrome save for index.php (this file doesnt have that javascript either)
i know its been a long post
thanks for reading
Learn how to search for strings in files on disk on your machine.
On Linux, MacOS and most unixen the go-to tool for this is grep. This applies to any programming language you work with. For your case simply cd into the directory of your source code and do:
grep -r SUGAR.collection .
If you're using git as your source control tool then git grep is much faster.
On Windows there are various GUI tools you can use to search for text in files. Just google: grep for windows.
If you're using an IDE then just your IDE's find-in-files functionality.
To track down specific code using Chrome / Webkit go through the following two steps:
Client:
1. Search all static text sources
Open the Dev Panel using CTRL + SHIFT + I
Hit CTRL + SHIFT + F for a global search dialog to pop up
Right next to it you can set pretty printing of the JS code to on: button { }
Enter your search term or terms using regular expressions
Optional: Decide if you need a case insensitive search which has a greater searchspace and takes longer
Example:
2. Search the dynamic user-DOM contents
Go to the Tab 'Elements' hit CTRL + F.
Enter your search term (This will also search iframes, svg's etc... within the parent DOM)
3. Recommended:
Cross-reference the results of step 1. and step 2.
If a given string is present in both the DOM and the static sources, then you can assume that the content is not programmatically created on the client-side.
Server:
Many projects perform a media bundling step prior to content-delivery. They pack web-resources into the main file (e.g. index.php) to save HTTP roundtrips.
Use sourcemaps / and or search the entire codebase for a salient static string or a salient keyword near the static string to locate the original source files.
Searching files:
Locally, I generally use the rapid index, and heuristic search of JetBrain's IDE's (IDEA, PHPStorm,...) and Sublime. The grep-command tool can definitely not compete here in terms of performance. On Windows I additionally use Totalcommander and its archive/regex finding abilities.
When quickly looking up code on the server you may use something like:
grep -r -C10 --color=always 'keyword1|keyword2' htdocs/ | less -R
which will also provide you with line-context. two caveats: you may want to filter out binaries first and symlinks outside the scope will be ignored.

How/when/where to include external javascript

I'm looking for some advice on the best way to hold my JavaScript (jQuery) functions.
I am developing in MVC/razor and therefore have a layout page. I include my jQuery library and an external JavaScript file in here so it's available in every single page.
This is working well, but I am now becoming very aware of the fact that I am adding almost 300 lines of JS to EVERY page, where maybe half of that is used in any one of these pages.
One function is not in the external file and instead sits inside the HTML because I need to use variables set in my razor code.
I have a couple of questions around this arrangement:
Is placing JS inside the HTML generally acceptable when variables set using razor are used? There does not appear to be a clean way of passing a variable into an external js file
Should I split my functions down in to individual JS files and just include what is needed for each page in the site?
If I were to split them into multiple files, how would that work with jQuery's (document).ready ? Do I need to use that if all the JavaScript I am including is to be used?
I'm sure this will more a matter of opinion than a black and white answer, but I want to consider all my options before moving on. Even though it works fine as is, I can't help but feel there is a better/cleaner way.
Remember once a user lands on your homepage and loads the javascript file it will be cached in their browser so subsequent pages will not download the Javascript again.
I would definitely keep the js separate, you could have a snippet on each page that initialise the JS that that particurlar view needs. Put something like the below in the views that need to run JS
$(document).ready(function() {
mysite.mypage();
});
Then the function mysite.mypage() can be defined in the external JS file.
300 lines isnt the end of the world, I would say its probably too early to be worryign about optimisation.
You could always look at minifying that JS file to decrease the size. A quick and easy way to do this is here:
http://www.minifyjavascript.com/
Have you ever heard of require.js? http://requirejs.org/ I find it really useful.
It's a module loader so you are able to split all of your JS code into individual files and load only the ones you need on each page.
I don't know about passing a variable to an external JS file, I don't think its possible / the 'right' way.
You can make each external JS file into a function that accepts and returns parameters. Then in the page you need to use it:
- include the file dependancy
- call the function
Thats what I do, seems like your 2nd suggestion.
for the $(document.ready) question its really up to you. You don't have to use it but its useful for some things , check out this overview:
http://docs.jquery.com/Tutorials:Introducing_$(document).ready()

How do I get the path of the currently running script with Javascript?

We have an IE extension implemented as a Browser Helper Object (BHO). We have a utility function written in C++ that we add to the window object of the page so that other scripts in the page can use it to load local script files dynamically. In order to resolve relative paths to these local script files, however, we need to determine the path of the JavaScript file that calls our function:
myfunc() written in C++ and exposed to the page's JavaScript
file:///path/to/some/javascript.js
(additional stack frames)
From the top frame I want to get the information that the script calling myfunc() is located in file:///path/to/some/javascript.js.
I first expected that we could simply use the IActiveScriptDebug interface to get a stacktrace from our utility function. However, it appears to be impossible to get the IActiveScript interface from an IWebBrowser2 interface or associated document (see Full callstack for multiple frames JS on IE8).
The only thing I can think of is to register our own script debugger implementation and have myfunc() break into the debugger. However, I'm skeptical that this will work without prompting the user about whether they want to break into the debugger.
Before doing more thorough tests of this approach, I wanted to check whether anyone has definitive information about whether this is likely to work and/or can suggest an alternative approach that will enable a function written in C++ to get a stack trace from the scripting engine that invoked it.
Each script you load may have an id and each method of the script calling myfunc() may pass this id to myfunc(). This means that first you have to modify myfunct() and finally alter your scripts and calls.
This answer describes how I solved the actual issue I described in the original question. The question description isn't great since I was making assumptions about how to solve the problem that actually turned out to be unfounded. What I was really trying to do is determine the path of the currently running script. I've changed the title of the question to more accurately reflect this.
This is actually fairly easy to achieve since scripts are executed in an HTML document as they are loaded. So if I am currently executing some JavaScript that is loaded by a script tag, that script tag will always be the last script tag in the document (since the rest of the document hasn't loaded yet). To solve this problem, it is therefore enough just to get the URL of the src attribute of the last script tag and resolve any relative paths based on that.
Of course this doesn't work for script embedded directly in the HTML page, but that is bad practice anyway (IMO) so this doesn't seem like a very important limitation.

How can I execute javascript in Bash?

I try to get to a page straight from Bash at http://www.ocwconsortium.org/. The page appears when you write mathematics to the field at the top right corner. I tested
open http://www.ocwconsortium.org/#mathematics
but it leads to the main page. It is clearly some javascript thing. How can I get the results straight from Bash on the first page?
[Clarification]
Let's take an example. I have the following lines for a Math search engine in .bashrc:
alias mathundergradsearch='/Users/user/bin/mathundergraduate'
Things in a separate file:
#!/bin/sh
q=$1
w=$2
e=$3
r=$4
t=$5
open "http://www.google.com/cse?cx=007883453237583604479%3A1qd7hky6khe&ie=UTF-8&q=$q+$w+$e+$r+$t&hl=en"
Now, I want something similar to the example. The difference is that the other site contains javascript or something that does not allow me to see the parameters. How could I know where to put the search parameters as I cannot see the details?
open "http://www.ocwconsortium.org/index.php?q=mathematics&option=com_coursefinder&uss=1&l=&s=&Itemid=166&b.x=0&b.y=0&b=search"
You need quotes because the URL contains characters the shell considers to be special.
The Links web browser more or less runs from the commandline (like lynx) and supports basic javascript.
Even though the title of the post sounds general, your question is very specific. It's unclear to me what you're trying to achieve in the end. Clearly you can access sites that rely heavily on javascript (else you wouldn't be able to post your question here), so I'm sure that you can open the mentioned site in a normal browser.
If you just want to execute javascript from the commandline (as the title suggests), it's easy if you're running bash via cygwin. You just call cscript.exe and provide a .js scriptname of what you wish to execute.
I didn't get anything handled by JavaScript - it just took me to
http://www.ocwconsortium.org/index.php?q=mathematics&option=com_coursefinder&uss=1&l=&s=&Itemid=166&b.x=0&b.y=0&b=search
Replacing mathematics (right after q=) should work. You may be able to strip out some of that query string, but I tried a couple of things and and it didn't play nice.
Don't forget to encode your query for URLs.
You will need to parse the response, find the URL that is being opened via JavaScript and then open that URL.
Check this out: http://www.phantomjs.org/.
PhantomJS it's a CLI tool that runs a real, fully-fledged Browser without the Chrome.

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