Live reload JavaScript in Chrome - javascript

I know you can live-edit JS from within the Source panel of Chrome Developer Tools, and I know there are systems for live-reloading of CSS, but can you live-reload JS from the source location (either a URL or local disk, or leveraging Workspaces somehow, or possibly even as a Chrome Developer Tools plugin)? In particular this would be insanely useful for CoffeeScript-to-JS setups.

It's surprisingly difficult to find anyone else trying to do this, considering how powerful it would be.
I've come close to achieving automatic live reloading of JS without page refresh; here's what I do:
In the inspector's sources tab, right click and choose "Add Folder to Workspace..."
Select to the local folder containing the .js you want to sync and click [okay].
Right click on the .js file nested inside your newly-added workspace folder and choose "Map to Network Resource", then select the matching .js from the page.
Make changes to the local .js file using an external editor.
Click on the .js file in the inspector, ensuring it has focus; this will trigger a "Recompilation and update" and your changes should be injected to the page.
Step 5 is the part that needs to be automated, somehow.
If you combine this with a file-watcher that automatically bundles your app into a single .js file, you can come close to automatic reload without refreshing the page.

Yes you can do that with grunt.js, or gulp.js. Other things like Codekit can do this, as can an add-on for Chrome called LiveReload.

Related

UwAmp server doesn't detect changes that've made in files

everyone!
I'm using UwAmp 3.1.0 for my php development but I had some troubles
with it.
It worked perfectly at the beginning and the server still works
perfectly now but whenever I made a change to a .js file or .php
file it doesn't reflect that change when I update the page in the
browser.
I went to the chrome dev tools and opened the source section to see if the file is exactly what I wanted but it shows the original version which I've amended a while ago. The links to all files are correct and they are in a subdirectory in www folder.
It's so frustrating as I can't see the changes in action. I checked
the syntax and everything is ok but it doesn't want to stop an
animation in jquery after I it was fully shown to the user.
Can you help me with this situation as I have no idea what's causing the problem here?
It should update the file instantly when I click refresh in the
browser but it doesn't and keeps loading the version of the files
that I started to work with.
Uwamp is AMP stack (Apache, MySql and PHP) and "out-of-the-box" it doesn't have anything with caching of files.
Apache is normally reading/getting files from Uwmap www folder "as is" so basically if your last change is saved into file in www folder (please check directly with tools like notepad) Apache will read it instantly.
This is related to your Browser Cache (Empty yours Browser/Chrome cache manually or install Chrome extension like [Clear Cache Extension]:https://chrome.google.com/webstore/detail/clear-cache/cppjkneekbjaeellbfkmgnhonkkjfpdn?hl=en) and try to clear cache but completely ("from begining of time" like Chrome said).
Also a workaround is to click that Empty Cache icon every save before refreshing the page beacuse it will clear it almost instantly (depending on how long time ago have you cleared your cache)
Also try to set OPCache in Php.ini (settings file) in Uwmap to Disabled (locate opcache settings in php.ini and put 0 to disable - you can access it from Uwamp GUI also).

How can I locate and debug a specific file in IE11 Dev Tools?

I have a file that is part of a legacy web site I'm maintaining that I need to debug - step into, etc. But I can't see how to do that. The site needs to be run in IE, in Compatibility mode.
When I run the site from VS (2013) by right-clicking the "http://localhost/..." item beneath the solution and selecting "View in Browser (Internet Explorer" and then hit F12, I see on the Debugger tab the file that has been set as the Default page (the "main" page I see after logging in), but from there I don't see how to open a different file - the one I need to debug.
There are a handful of files apparently available for selection beneath the folder icon:
...but not the one I need. If I enter its name in the search box, I get, "No results found." It is beneath a pages folder, but so are those that are displayed. What makes them special? Why can I select those undesirables, but cannot select the only page I care about?
I assume you have the JavaScript file you want to debug somewhere in dist. Just go to that file and write debugger; inside the function you want to debug. The open dev tools in IE and reload the page. Initiate an action that should invoke that function with debugger (if it was not done on page load) and you will be able to debug it.

How do you open a file folder through a link on website in Firefox and Chrome?

I'm working on a web application that needs to have a link which opens a documents folder from a file server. The folder can be opened either in a new browser tab or new window, or using the computer's default file browser program (i.e. Windows Explorer). This javascript should do the trick:
window.open('file://///fileserver.companyname/public/Documents/','_blank);
and this html should also work:
Open Documents
but these both only work in Internet Explorer, and our users always use Firefox and Chrome. Apparently the default security settings for Firefox and Chrome don't let you open a "file://" when the request is called from an "http://" website.
I've seen several references to this page: Links to local pages do not work which describes why you can't open files from webpages using Firefox and offers a few workarounds. Unfortunately, it only offers two options: install a plug-in on each browser instance, or create a user preferences file for each browser instance. Neither of these options are acceptable because we have too many users. The company I work for is not willing to apply anything to each machine which needs to access this link. Aside from that, I tried both plug-ins and the preferences file anyway, and the only one that worked for me was the IE Tab plug-in. I think the reason LocalLinks didn't work is because I'm trying to open a folder, not a file.
This stackoverflow question described similar options for Chrome: Can Google Chrome open local links? but again, the LocalLinks plug-in didn't work for me and plug-ins aren't acceptable anyway.
I also found a website that suggested to use a command line argument top open files in Chrome (http://www.askyb.com/chrome/open-local-file-in-google-chrome/) and one that showed how to apply the argument automatically (https://askubuntu.com/questions/160245/making-google-chrome-option-allow-file-access-from-files-permanent), but if I read it correctly it still involves applying changes to every computer accessing our website.
Is there any way to open a file folder in both Firefox and Chrome entirely programmatically i.e. within my web application C# or Javascript code without installing a plug-in or adding a preferences file to individual computers? I cannot alter any of these business requirements.
Sidenote: We are using C# with MVC 4. I would prefer to open the folder using a Controller Action in C# (because I'd like to create the folder before opening it if it doesn't exist yet), but javascript or html on the client side is acceptable. For Internet Explorer, I can create that javascript in the C# code by wrapping it in the JavaScript( ... ) function built into MVC C# Controllers. When testing IE Tabs in Firefox and Chrome, I had to define it as an href link, not a function that opens a window, or IE Tabs wouldn't recognize it as a link. But neither of these were acceptable workarounds for our business needs.
The request was dropped before I could come up with a feasible solution, but in case anyone else is still struggling with this problem I will describe workaround that would not require any workstation customization.
They don't technically need to use the built-in file explorer to open a folder. Instead, a creative way to display the information the business wanted without breaking any browser security rules would be to iterate though the files without opening the file explorer and then display a list of folders/files in a browser window.
Using Directory.EnumerateDirectories(filepath) and Directory.EnumerateFiles(filepath) you can get a list of folders and files to display. When the user clicks one of the folders, call these methods again to get the next level of folders and filenames. When the user clicks a file, download/open it. These methods return the folder and file names as lists of strings, so you would just need to render the lists with custom icons in the browser. (The methods are from C#'s System.IO library.)
here is the simple html code:
<input type="file" webkitdirectory>
but the problem with this code is that it works only on google!

Chrome Dev Tools - Modify javascript and reload

Is it possible to modify the JavaScript of a page and then reload the page without reloading the modified JavaScript file (and thus losing modifications)?
This is a bit of a work around, but one way you can achieve this is by adding a breakpoint at the start of the javascript file or block you want to manipulate.
Then when you reload, the debugger will pause on that breakpoint, and you can make any changes you want to the source, save the file and then run the debugger through the modified code.
But as everyone has said, next reload the changes will be gone - at least it lets you run some slightly modified JS client side.
Great news, the fix is coming in March 2018, see this link: https://developers.google.com/web/updates/2018/01/devtools
"Local Overrides let you make changes in DevTools, and keep those changes across page loads. Previously, any changes that you made in DevTools would be lost when you reloaded the page. Local Overrides work for most file types
How it works:
You specify a directory where DevTools should save changes. When you
make changes in DevTools, DevTools saves a copy of the modified file
to your directory.
When you reload the page, DevTools serves the
local, modified file, rather than the network resource.
To set up Local Overrides:
Open the Sources panel.
Open the Overrides tab.
Click Setup Overrides.
Select which directory you want to save your changes to.
At the top of your viewport, click Allow to give DevTools read and write access to the directory.
Make your changes."
UPDATE (March 19, 2018): It's live, detailed explanations here: https://developers.google.com/web/updates/2018/01/devtools#overrides
The Resource Override extension allows you to do exactly that:
create a file rule for the url you want to replace
edit the js/css/etc in the extension
reload as often as you want :)
In the devtools preferences check the Enable local overrides.
Go to network tab, find the file you want to edit, rigth click on it and select Save for overrides (on the sources/overrides tab you need to add a local folder)
The file appears in a new tab on the Sources tab as local copy, so you can edit this file, and after site reload the new (and edited) override file will load on the site!
I know it's not the asnwer to the precise question (Chrome Developer Tools) but I'm using this workaround with success: http://www.telerik.com/fiddler
(pretty sure some of the web devs already know about this tool)
Save the file locally
Edit as required
Profit!
Full docs: http://docs.telerik.com/fiddler/KnowledgeBase/AutoResponder
PS. I would rather have it implemented in Chrome as a flag preserve after reload, cannot do this now, forums and discussion groups blocked on corporate network :)
Yes you can eazily!
Source -> filesystem -> choose the conatainer folder -> allow access -> open your file, edit and save.
https://www.delftstack.com/howto/javascript/edit-javascript-in-the-browser/

firefox addon: Talking back to the script

I am new to extension programming but find making extensions in Chrome much more easier, but now that I am trying to port my test extensions to FF I have a few questions of how to do the same things I do in Chrome... now in FF.
For example:
In Chrome I have a page in my extensions directory called: domains.html
I link to that page from my popup and it has access to all my scripts etc but the "outside" world cannot directly access that.
Is there any such thing in FF so that I can show a page that is in my add on folder and has access to my add-on's JS and other files?
Thanks!
Take a look at some of the docs for opening URLs in new Tabs and manipulating the content of the tab:
https://developer.mozilla.org/en/Code_snippets/Tabbed_browser#Opening_a_URL_in_a_new_tab
Once you get comfortable with that, try opening an HTML page that lives in your add-on. First, you need to be aware of the 'content' package name you registered in your chrome.manifest file. Second, make sure your 'domains.html' file is in the content folder of your add-on. To open the web page in a new tab using a button or menu in Firefox use code like this:
gBrowser.addTab("chrome://mypackagename/content/domains.html");
You can should be able to load other JS and CSS files from your add-on into the web page using similar chrome:// URIs.

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