Is it possible to get a proper JavaScript source file if I have the minified file and its corresponding source map?
I know how to prettify JS code (line-breaks and indents), but I would like to get original function / variable names in the file, to be able to better understand the source code.
I would like to get the un-minified JS file to work with, instead of using it to debug in a browser.
PS It is probably somewhere right under my nose, but I didn't manage to find it so far. Sorry if this was already asked!
To work sourcemaps requires both files, minified and original, often original is included in sourcemap file(it has optional sourcesContent for sources that can not be hosted).
Sourcemap is just JSON file, and you can found all needed information inside:
sources - list of source file names,
sourcesContent - optional list
of original sources, if source is not presented it would be null
here.
Utility script, I have written before for this purpose: https://gist.github.com/zxbodya/ca6fb758259f6a077de7
I suggest using the Source Map Visualization tool online to view the original code with both js file and js soucemap file.
https://sokra.github.io/source-map-visualization/
I think you won't be able to completely revert such code to its original state as a lot of information (for example comments or certain variable names) is simply lost in the process. When I understand it correctly for sourcemaps to do this you still need the original file.
If you only aim to prettify the code so its readable again you do not need source maps. Many advanced editors have such functions. For example if you are using Sublime text there is this plugin: https://packagecontrol.io/packages/HTML-CSS-JS%20Prettify which does a great job.
Also see this similar question: How can I debug a minified JS in firebug?
Related
I'm trying to see whether it's possible to use the code from DuckDuckHack Instant Answers outside of the context of the main DuckDuckGo website. After all, an Instant Answer is mostly a standalone component that consists of some HTML, CSS and Javascript and should be relatively self-contained and reusable.
Since the DuckDuckHack project is in maintenance mode, it seems to be a bit difficult to obtain information: the Slack and Forum mentioned on the Developer Guide have been disabled. I tried to find out whether other people tried to make Instant Answers work in other contexts, but I couldn't find anything. There are tutorials on writing Instant Answers, such as this using Perl and the DuckPAN tools. I tried to get an existing Instant Answer to work using those tools but I failed to get it to work properly (not sure whether they are still maintained).
Since those tools seem to be a bit heavyweight, I thought it could be possible to bypass them completely and try to just use the HTML, CSS and JS from the Instant Answer directly.
I've given the Calculator a first shot. I identified the relevant source code in the duckduckgo/zeroclickinfo-goodies repository's directory share/goodie/calculator. The HTML seems to be in the content.handlebars, and then there's calculator.css and calculator.js. I created a plain HTML file, put the HTML from content.handlebars in there and included references to the CSS file and the JS file. At first, the CSS wouldn't work because the CSS rules don't apply without adding some more wrapper divs that can be easily found when inspecting the DuckDuckGo site with the calculator Instant Answer visible. After adding those wrapper divs, the calculator UI appears more or less intact. However the buttons of the UI do not work at all yet.
Looking at the Javascript console I get this error:
Uncaught ReferenceError: DDH is not defined
at calculator.js:1
Apparently an object DDH is required by calculator.js, however I have no idea what that object should be and how I could create it.
Does anybody know how this DDH variable gets usually initialized or more generally how to make this work? Any reference to projects reusing the code from DuckDuckHack for their own sites would also be highly appreciated.
I think the details of how the DDH object is put together might not be exposed through the open-source portion of DDG.
I've also made some attempts to repurpose some of the built-in DDG IA functionality (e.g. get programmatic access to the many, useful instant answers unavailable through their API).
In the process, I cloned the goodie repo and poked around. The pattern seems to be that for most goodies the payload to be displayed is DDH.<goodie>.content. In my local copy of the goodie repo:
$ grep -rE 'DDH' ./lib/
./lib/DDG/Goodie/Conversions.pm: content => 'DDH.conversions.content'
./lib/DDG/Goodie/Conversions.pm: content => 'DDH.conversions.content'
./lib/DDG/Goodie/Game2048.pm: content => 'DDH.game2048.content'
./lib/DDG/Goodie/PublicDNS.pm: list_content => 'DDH.public_dns.content',
./lib/DDG/Goodie/JsBeautifier.pm: content => 'DDH.js_beautifier.content'
./lib/DDG/Goodie/SassToCss.pm: content => 'DDH.sass_to_css.content'
./lib/DDG/Goodie/Constants.pm: title_content => 'DDH.constants.title_content'
...
On the javascript side of things, you'd find the corresponding .js files in the share/goodie directory, as you did for the calculator goodie.
The <goodie>.js files seem to introduce DDH.<goodie> namespaces (typically right at the top of the file) and define DDH.<goodie>.build functions. This procedure is referenced in the goodie-display docs (see the section titled Setting Goodie Display Options on the Front end therein).
Nowhere in the docs, though, is it documented how the content property of DDH.<goodie> is put together. I cloned the docs repo and grepped for DDH, revealing nothing to that effect.
None of the .js files in the share/goodie folder of the goodie repo, though, seem to give a clue as to how DDH.<goodie>.content is assembled either. Indeed, some of those .js files do not even contain the string content. For a listing of all share*.js files that do contain the string content, I did (in the local copy of the goodie repo):
$ find ./share -name "*.js" |xargs grep -l 'content'
./share/goodie/countdown/countdown.js
./share/goodie/text_converter/text_converter.js
The other .js files do not contain that string at all..
Edit
On the other hand though, I see you did manage to get the calculator going with some modifications to the .js file (e.g. by inserting that missing DDH namespace).
After using grunt.js to minify my code, how would I beautify the code again and restore the variable names (as if I had never minified it in the first place)?
I have found a lot on here about jsbeautifier.org but that doesn't help me if I need all the variable names restored
Generally you probably want to save a copy of the original (un-minified/ un-uglified) code, but if you do need to revert back from minified code you could use source maps. Check 'em out here.
The purpose of minifier is to obfuscate the code. You don't want to be able to unminify a minified file.
You want to keep the original file and you can also generate a sourcemap that'll link the minified file with the original.
All the variables after minifications are defined just with one or two letters. Is there any tool or technique which can help finding the right variable I am looking for in the javascript code?
For example, I found google doodle soccer game: https://www.google.com/logos/2012/football-2012-hp.html and now I try to find the variable there the score or final score is saved. So I can make the highscore table for the game.
Any tip is welcome.
There is a nice tool called jsnice
What is JSNice?
JSNice is a new kind of statistical de-obfuscation and de-minification
engine for JavaScript. Given a JavaScript program, JSNice
automatically suggests new likely identifier names and types.
jsnice is different to other 'javascript beautifiers' in the fact it does not only formats the minified code, but is also predicts meaningful variable names.
Generally you want to avoid working with the minified source. Try to find the original uncompressed source with the full variables names.
I have never been able to successfully make changes to a minified Javascript file. My Javascript skills are pretty good but minifiers make it very difficult to work out what the code is actually doing.
Source Maps are newer thing that help solve this problem: http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/. But unfortunately in your case this will probably not work as Google has not provided a source map.
If you are forced to make changes to the minified source, try using some like http://jsbeautifier.org/ as #Mustafa_sabir suggested. Then try to figure out what each of the variables are. You could then either remember what they do or try renaming to something more meaningful.
Good Luck!
There is no way to recover Minified Javascript variable names unless the Javascript code or library have a map file to decode the original code in the Inpsector view of the browser.
In your example, It is not possible.
I am using Dreamweaver CS6 (and most recently, CC).
We have a javascript file that is included in every page, but its dynamically included through nested layers of PHP includes, so when I type in a function name, DW does not know it is part of the page, and therefore does not give me the code hints (vs if I am actually in that js file, code hinting works like a charm).
I am looking for a way to have DW pick up that file and/or give me code hints for any functions and namespaces I place in there, but so far, have come up empty.
Has anyone had any success with doing this?
I have been searching for this answer for far too long, and I think I've found it! It has to do with "site-specific code hinting". Take a look at this link: https://www.inkling.com/read/dreamweaver-cs6-missing-manual-david-sawyer-mcfarland-1st/chapter-22/php-code-hints
It worked for me. I am now able to see all variables from nested includes.
I'm developing on top of OpenLayers.js. My project folder is structured as follows:
project /
|-- OpenLayers.js
|-- map.html
|-- map.js
\-- etc
As you can argue, when I start a new map project, I espect suggestions from Vim on how to complete the code, reading JS classes from all the libraries in the project folder (in this case, just OpenLayers.js).
E.g.:
map = new OpenLayers. --> <C-x><C-o>
map = new OpenLayers.Bounds
.Control
.Map
Selecting one of the suggested classes I should get a kind of autocompletion, like in Aptana. I've installed AutoComplPop and I get a nice automatic menu to select suggestions, but all of them are taken from the current JS file.
Anyway, I've correctly set up Tagbar + node.js + jsctags and I've generated tags file for my project, and added set tags=./tags,./../tags,./*/tags to my .vimrc.
In this case, also, Tagbar maps the current file JS structure but doesn't offer any mapping of the classes coming from other files.
Another probably relevant line in my .vimrc:
autocmd FileType javascript set omnifunc=javascriptcomplete#CompleteJS
I'm struggling to get class and subclass suggestions and now I'm getting a bit confused with all the plugins/piece of software available.
Any hint?
Thank you guys :)
Check out YouCompleteMe and tern_for_vim.
Here's an article about using them together.
Your expectations are a bit too high. Vim is not an IDE like Aptana and the mechanisms used to provide completion are crude.
Did you check that your tags file has OpenLayers.Bounds, OpenLayers.Control or OpenLayer.Map? I can't find OpenLayer.Map and, going through the OpenLayer.debug.js I can't find this function either.
TagBar only works with the current buffer. If you want to show tags for other windows/buffers you'll need another older plugin: TagList.
AutoComplPop doesn't support JS out of the box. How did you set it up? Here is how I did but it still uses <C-x><C-o> while completion from tags is done with <C-x><C-]>.