Rosetta Code:Village Pump/Javascript Functionality Add

From Rosetta Code
Javascript Functionality Add
This is a particular discussion thread among many which consider Rosetta Code.


Discussion of adding functionality to RC using JavaScript.


The Goals

  1. Come up with the most useful feature additions you can think of for Rosetta Code.
  2. Implement them in JavaScript such that they work with IE7+ and Firefox 3.5+. (Broader support is awesome, but not strictly necessary.)
  3. The features shouldn't be necessary for use of the site.

The most useful and stable features will be added to the site-wide JavaScript load.

To consider

  1. Take a good look at the CSS involved and surrounding code examples; Ages ago, I added CSS classes that the site highlighting doesn't use, with the intent of enabling programmatic awareness.
  2. For the moment, consider any exposed functionality and structured formatting on the site fair game; I don't know that any of it will be removed in the foreseeable future.
  3. Don't forget about the MediaWiki API.
  4. If you'd like some changes server-side, mention it. If it can be done within reasonable resource requirements (server and my own time), and isn't a major problem in some other respect, I might do it.
  5. If you've got ideas for features that could be implemented in JavaScript, but don't have the ability or urge to implement it, mention it; perhaps someone else will pick it up.
  6. If you're limited by testing resources, mention it; perhaps someone with another browser will lend a hand.
  7. If you're hampered by problems with the way the site content exists, this would be a good time to identify specific limitations and fix them where possible.


  1. Inclusion to sitewide JS load, for whatever that's worth.
  2. My appreciation, for whatever that's worth.
  3. Maybe, just maybe, I'll be able to send a specialized T-shirt, mug, greeting card or some such. It depends on how many people I'd have to send to.
  4. What do you need prizes for? I thought you guys all coded because you enjoyed it! --Michael Mol 14:01, 19 May 2010 (UTC)

Further discussion

Language comparison script

Rosetta Code:Language comparison script

This script puts checkboxes next to each language in the ToC which can be checked to compare a number of languages. I chose to leave them underneath the ToC rather than floating them next to it due to the observation that many of the examples have fairly long line lengths, making side-by-side comparison rather difficult space-wise.

--Tyrok1 00:16, 20 May 2010 (UTC)

I took the liberty of playing around a bit with the DOM after your script did its job: File:Compare Languages Concept.png. Depending on the display resolution a side-by-side comparison of at least two languages should be possible in most cases, I think. The ToC in its smaller form there might need work; that doesn't look too compelling yet, but it's at least much shorter (vertically) than before. But that was just a rough idea what could be done. Overall I think a side-by-side view would be quite nice to have. —Johannes Rössel 06:22, 20 May 2010 (UTC)
Jeepers, have you got a large screen.  :) I'll see what I can do. --Tyrok1 14:07, 20 May 2010 (UTC)
New version's up at the same link - Rosetta Code:Language comparison script Please let me know what you think. --Tyrok1 21:01, 21 May 2010 (UTC)
The script is on its own page now. The links are updated to reflect this. --Tyrok1 03:19, 23 May 2010 (UTC)
Updated links after moving page to Rosetta Code namespace. --Tyrok1 03:18, 25 May 2010 (UTC)

Could this maybe be changed to that it doesn't show the boxes on talk pages? Sometimes they get enough sections to get ToC's, but they don't need to be compared. Unless it would be advantageous to only show some sections of talk pages...? --Mwn3d 03:18, 26 May 2010 (UTC)

The new version is supposed to only activate if it's on a page that's in the Programming Tasks category, so in theory it shouldn't do that anymore. However, it's certainly possible you found a bug, and if the new version's still doing that, can you post an example link? --Tyrok1 23:17, 26 May 2010 (UTC)

Direct links to language examples when coming from a language page

Just a random thought/idea: Since languages are categories they simply aggregate all pages that are tagged with that category. For languages hwoever, there is also a pretty rigid structure on this site concerning where the interesting part (concerning a particular language) is on a task page. Currently the links to the tasks from a language page simlpy link to the task page (which for a normal Wiki is fine since it's the page that's in the category, not a section). But on RC those links could – theoretically – link directly to the appropriate section (which is probably what a user might expect when clicking on a task link on a language page).

For most languages this is rather simple, I think, since the anchor name on the task page is identical to the language's name (which is also the category name for that language). However, for a few languages, including C# and F#, this doesn't quite work, as their categories are named »C sharp« and »F sharp« and the anchors use »C.23« and »F.23« (apparently url-encoded and % replaced by .). The name used in the anchors appears to be nowhere to grab for JS on the language page, although this might be solvable with converting the infobox into a template which makes the intended/canonical name accessible via a <span class='intended-name'> or so. –Johannes Rössel 21:18, 21 May 2010 (UTC)

See language page links (includes code). BR 01:38, 21 November 2010 (UTC)

Per-code example buttonbar

Buttonbar set per-code example. Including features like:

Didn't add Collapse/Shrink, as I'm not sure this is necessary with the language comparison script. Didn't add Show/Hide Tags as I don't believe there are tags yet to show or hide. However, this script implements Select All, Copy to Clipboard (in IE), and Try on Codepad:
Rosetta Code:Per-Code Example Buttonbar
--Tyrok1 01:14, 6 July 2010 (UTC)

Just made a change that should fix it. If you could try it out again and let me know if it works, that'd be great. --Tyrok1 12:08, 13 July 2010 (UTC)

Syntax highlighting selector color picker

Color picker for GeSHi highlighting CSS selectors. Save to cookies or HTML5 local datastore. (There's currently no serverside datastore for RC) --Michael Mol 20:36, 26 June 2010 (UTC)

Give this a try - Rosetta Code:Syntax Highlight Color Picker. --Tyrok1 19:32, 3 July 2011 (UTC)

Live version of all JS + HTML examples

Implement a button (possibly in the corner button bar) where you could try out any JS + HTML example on the site. You could easily do this by detecting which <pre> tag in the example was HTML and assuming the other (if it exists) is JS, popping open a new window, and inserting this code into it. If there's a separate <pre> tag for JS, it could be inserted into the HTML before being placed in the new window. --Tyrok1 00:24, 13 July 2010 (UTC)

I've been thinking about that, but that's leaving things way, way open for arbitrary code execution in an unsafe environment. I was thinking about crypto-signing code examples, but that's too complicated. The next best option I can think of is dumping the JS code into an HTML page, allowing the user to save the option to save it to disk, and then let them open it there. --Michael Mol 00:32, 13 July 2010 (UTC)
I would think having the user save out the code to a file to run it could potentially be even more problematic, as the domain's local to the computer. If you've got code that's visible to the user and they click the "Try it" button, I would think the window should be sandboxed to the RC domain, preventing cross-domain requests to other sites. There are a couple potential risks I can see, but I don't think the likelyhood of them happening is great and if they did happen, the access they have would be very limited due to browser security constraints. Could you clarify your main concerns a bit more so we can see if we can work around them? --Tyrok1 00:56, 13 July 2010 (UTC)
Local to the RC domain is worse, from a wiki integrity standpoint. If the scripts were run at (subdomain), can the get access up to Or would I need a sideways domain to limit it? --Michael Mol 01:56, 13 July 2010 (UTC)
IIRC it's generally limited to the subdomain, and in this case I believe it would be the subdomain of the task page. Unless you had some kind of a server-side script on a separate subdomain that would just echo back anything it got from a GET request. Otherwise you wouldn't be able to access it from the task pages. This would sandbox it into its own subdomain, but I would suspect it would be infinitely worse by being exploitable from outside the site for phishing attacks against users unless you were to limit it to only requests that come from the domain name. Another solution would be to have someone evaluate the code and place it on a page where it's locked down permission-wise and have the script check to see if one of th10ese is available. As it is, the solution I've seen used is that people are hosting examples on personal websites and linking to them, which is fine from a wiki integrity point of view, but from a convenience and user security point of view, I'd consider it a lesser option. Any other thoughts/ideas? --Tyrok1 02:28, 13 July 2010 (UTC)
Running it on a separate domain was what I was thinking about, using signed requests. I was thinking of running the code+salt(server-only-known secret key)+salt(timestamp mod (sitewide cache expiry time)) through a hash, and verifying that signature on the echo side. The problem is whether I would need to register a separate, or if would be secure, from a JS standpoint. --Michael Mol 13:40, 13 July 2010 (UTC)
From my experience, a subdomain should be sufficient. --Tyrok1 13:45, 13 July 2010 (UTC)
Any browser with a debugger (chrome, firefox with firebug or venkman, and probably others) lets you do this already with a copy and paste. --Rdm 14:55, 13 July 2010 (UTC)
Not everyone has access to browsers with debuggers (most notably those in locked-down environments), so it still strikes me as a worthwhile pursuit. --Michael Mol 14:57, 13 July 2010 (UTC)
Hmm, ok... but a locked down environment which prevents the kind of javascript inspection allowed by a debugger and which allows or requires execution of javascript from arbitrary web sites is just asking for problems. --Rdm 15:05, 13 July 2010 (UTC)
The implementation I had in mind would only echo back code+execution if it said code were signed using a timestamp(the server has a cache timeout, and I was thinking of using that as the basis for the timestamp precision.) and server-secret key (only known to my MW install and to the echoing script). That way, debuggers aren't disabled by the echo'd page, and the only code sent by the server is known to come from the RC wiki. As for client-side environments that prevent users from making changes, but don't apply additional restrictions on server-provided content, well, those environments are pretty common. I've worked in one or two, and cleaned up a half dozen more. --Michael Mol 15:13, 13 July 2010 (UTC)

"My Scripts" Menu

Rosetta Code:My Scripts Menu

This script adds a "My scripts" menu next to the "My preferences" button which allows users to choose which JS modules they want to use. It stores the state of these choices in a cookie so it can automatically load the same modules whenever they navigate to a new page. --Tyrok1 22:28, 18 July 2010 (UTC)