I was recently tasked to document a large JavaScript application I have been maintaining for some time. So I do have a good knowledge of the system.
But due the sheer size of the application, it will probably take a lot of time even with prior knowledge around the code and the source code itself in uncompressed form.
So I'm looking for tools that would help me explore classes and methods and their relationships in JavaScript and if possible, document them along the way, is there one available?
Something like object browser in VS would be nice, but any tools that help me get things done faster will do.
Thanks!
Firebug's DOM tab lets you browse the contents of the global window object, and you can inspect a particular object by entering inspect(whatever) in the command line.
You won't be able to use it to detect relationships unless an instance of one object holds an instance of a related object, but it's a start.
You can also use the Options menu on the DOM tab to restrict what's shown to user-defined functions and properties, which should help reduce clutter.
Take a look at Aptana, they have an outline that can help you to determine what are the objects and somtetimes their relationship.
Firebug + uneval(obj) is a simple trick that is often helpful.
I see a lot of people talking about examining the DOM within Firebug. However, from your question it looks like you want something like jsdoc? just add type and class information through comments and jsdoc generates documentation including class relationships. http://jsdoc.sourceforge.net/
Google has a fork of it with added functionality http://code.google.com/p/jsdoc-toolkit/
UPDATE: It's not a fork, it's a rewrite by the developer that wrote jsdoc originally as a perl script. It aims at being more adaptable so you can use whatever js inheritance/events/properties style you'd like. Another feature is that it lets you modify the templates used to generate the HTML in a much simpler way.
We don't know if this JS application is designed to run in a Web browser...
If yes, as advised, Firebug (a Firefox extension) is excellent at debugging JS and exploring Dom.
On the IE side, you have some tools like IEDocMon, Web Accessibility Toolbar (it does more than its name) or Fiddler (unrelated to your question, but still a good tool to have).
Firebug (Firefox) / Dragonfly (Opera) can help you with viewing objects in realtime
Aptana / JS/UML(Eclipse) can help with relationships of objects
This is an old question, but let me answer it anyway.
Use an IDE. Integrated Development Environments were made for jumping around rapidly among the code. The key features you will exercise during exploration are viewing the file structure or outline, jumping to a declaration or usage, and searching the entire project for all instances of a string. If you are using WebStorm, set up a custom scope for files except generated files and node.js to aid in searching.
Run 'npm la | less' which lists all your dependent modules with one line descriptions. You may have never seen moment.js and never need to read the documentation, but taking the time to read a one line summary of it is worthwhile. If you need more information on a tool than one line summary, search for the term on SlideShare. Slides are faster than ReadTheDocs.
Document a little as you go. I'm a fan of forcing people to use notebooks constantly rather than scratch paper. Also, I find adding a one line comment to each JavaScript file is worthwhile. You want to know what should be in each directory of your project. I also recommend building a glossary of the exact meaning of domain terms in your system, e.g., what does "job" in your system.
Finally, you may need to just fire up the application in a debugger and start stepping through parts of it. Most large projects have accreted worth from programmers of various skill levels and motivations.
You are aiming for a level of "conceptual integrity" (to quote Yourdon) or to "grok" the software (to quote Heinlien). It does take some time, cannot be bypassed, and can be done efficiently.
Related
A question about existing tools.
Background:
I have a system where we uses versioning a lot. To compare versions we now dumps the information to a text-format and then print the two versions of the text with colored markings. I doesn't look nice and is quite hard for the users to understand.
I'd like to improve on this and actually show the two versions web-pages redered markup and then use some kind of css-markers to show where there are differences between the two pages. What I imagine to be the problem with this kind of apporach is that there are a lot of objects in the dom that doesn't directly affect the rendering and therefore would need to be filtered away for the diff to make sence.
Question:
Is there any existing tools that would allow me to compare the doms of to pages and then render apply some kind of visual clues to what is added, changed or removed? It needs to run in the browser only.
Is it a viable approch at all?
One way to achieve this is by taking screenshots (automatically) of the 2 dom structure and comparing those images. that way you are not saving/rendering the dom. you can even use a headless browser like node to do it for you, making it quick and easily integrated into your automated testing.
There are several tools to help you do this rather then writing your own from scratch, such as resemble.js. (however if you prefer you can use phantomjs and casperjs to write it yourself using their api's.
These tools allow you to highlight the differences in two images
there is also a good article here on automated-screenshot-diff which is another node package that can compare two screenshot of dom renderings.
I'm writing a UI to my R script, which asks the user some names of organisms and the location of a folder, using javascript/html that will be local (not hosted, ever).
At the moment, I have just that: a couple of text boxes that take input and pass an executable R script. Originally this UI was being written as a very user friendly option, but slowly I've realized that some nifty tricks can be added such as a textbox that completes the word for the user (so if the user misspells the name of the organism, the UI will correct the input based on the files uploaded. And this would come from a list of organisms text file that R would generate immediately once the files have been added).
Is there a way to make this more efficient? For example, retrieving plots from R (as .pngs) and updating my local webpage and being able to share a log file between R and the UI (mind you, I am aware of the potential File I/O errors)..but for the sake of brainstorming.
I'm aware of Shiny, but what I would like is a simple local UI, as I will be dealing with big data (average ~ 1 gigabyte worth of files that my script will process).
Another way to ask my question that is more to the point:
Here's an example of integrating PHP and R: http://www.r-bloggers.com/integrating-php-and-r/
I am looking to create something similar with javascript/css/html/jquery etc.
Thanks
You could definitely use nodejs (nodejs.org) for that. Take a look at https://github.com/elijah/r-node and r-node. Confusingly enough, this is two different projects with the same name. More info on the latter here: squirelove.net/r-node/doku.php
In recent years JavaScript has become one of the fastest programming languages. In one case I know of, JavaScript is faster than C++. See: benchmarksgame.alioth.debian.org/u32/performance.php?test=regexdna
Bear in mind, though, that memory is very difficult to manage in JavaScript, so you should run some sort of memory leak detection program on your code, if you plan to create long running processes.
E.I: memwatch (npmjs.org/package/memwatch) or nodeheap (npmjs.org/package/memwatch)
Good luck with your endeavors!
PS. sorry for the lack of real links. I'm apparently not allowed to post more than 2 links.
Why wouldn't you be able to use Shiny locally? You design your app on your computer and run it locally with runApp('myapp') from an R-prompt. Unless you are experienced with javascript I would give shiny another look: http://www.rstudio.com/shiny/
The example you linked to can be very easily implemented using Shiny. See link below for a tutorial on how to write the app:
http://rstudio.github.com/shiny/tutorial/#hello-shiny
To run that example locally:
install.packages('shiny')
shiny::runExample('01_hello')
I have a similar case, and shiny looked like a good idea to me. However, after I did a few first steps, I am no longer sure about this. Note that most of the examples use shiny to display results. When you get into editing some fields and using a database, things can become messy; the reactive-ness gets in the way once fields can be change by program and by the user.
As an example see https://gist.github.com/dmenne/4721235/edit. The main problem for the current state of shiny is that you must use the dynamic UI for this type of work, which kills any separation of ui and server because you have to create the ui elements in the server.
shiny is a great idea, but for anything larger with interaction it is too early now. Knowing that the amazing RStudio team is behind it, I am sure the stress should be on now.
What else is there around to make user interfaces for R? TclTk makes me shudder. I working in c# a lot, and I had been using R(D)COM for interfacing some years ago, but gave up after installation and licensing problems. There is R.DOTNet which works better now; it is the most hazzle-free installation-wise, but it is not a very active project, and tends to crash. Interfacing via RServe/RServeCLI is stable, but is too difficult to install on Windows, for example on hospital computers with their strict security issues.
And there is Qt. With the active RInside community, it would be a good choice and the interface is great. I wish however my programming skills were at the level of the RStudio-guys. The fact that even Dirk is one the proof-of-concept level (using rinside with qt in windows) is not encouraging.
These days when I code JavaScript I find myself using more and more plugins to accomplish common tasks. Often times when I use an existing plugin, e.g. to display tooltips, I'm not quite happy with certain options - so I extend them, or fix a bug.
This raises the question on how to fix/extend third-party code. Do you just modify the source file? That makes it almost impossible to update the plugin at a later date. You could extend it, by cloning the object or prototyping the existing one. But this often leads to duplicate code or scoping issues.
I've played with the idea of modifying the plugin code directly and generating a patch file at the end. These could then be applied "on build" with phing or some similar framework.
How do you folks handle this problem? Are there any existing projects/frameworks to make this easier?
Thanks for your thoughts.
If the third party code is a good citizen of open source, you fork it, enhance it, write tests for your enhancement, and submit a pull request back to the project's maintainer. Then your enhancement is available for all to use, including you. This is how open source happens.
If it's open source, but not a good citizen of open source, (no active maintainer, or perhaps your enhancement is too specific or unwelcome for some reason) the process is the same, they just never accept your pull request. Later in the future you can merge in changes committed in the official repository on top of your own in your private repository, even if they never make it into the official repository of the project.
This is the reason distributed version control systems like git are so awesome. No one owns the only canonical repository, and your private hacked version can be hosted and treated like the official version very easily.
Of course, most of that assumes that the project is on GitHub somewhere. If it's not, well, things get much more tricky.
I've written a JavaScript application that runs off Prototype & Scriptaculous. I'm thinking of rolling it out in as an open source product & would like it to be able to run on jQuery as well — I typically use jQuery for most of my other apps, except the site this app was originally built for.
I was originally thinking about building two separate applications, but maintaining them would be time consuming. Instead I'm considering building a library abstraction layer that detects if the page is running jQuery or Prototype and then calls the appropriate methods. I'm not going to abstract the whole libraries, just the functionality applicable to my application — namely selectors, events & effect. The core of my app is under 500 lines of code, so there isn't too much I need to worry about.
So instead of calling $('id') I would call LA.$('id') (LA for Library Abstraction) which would call $('id') in prototype and $('#id') in query etc…
Does this sound sane? I can't think of any technical hurdles, although I would have expected someone to have attempted this before. I couldn't find anything similar in my searches.
I expect that if you support the libraries only partly then no one will choose to use it, as they would have to finish the support, and you may find that maintaining it will be a headache, as there will be requests to add more functionality.
If your application is so small, why not just switch to jQuery for it, and standardize on that, as MS has done.
You may run into problems with versions, as, if someone uses it, and they are using an older version of a library, and there was some API change, then they will be wanting you to add support for that library.
I believe Ext.Js does something similar. They have a concept of "adapters" which allow you to sit Ext.JS on top of any of the underlying libraries and it will just work. The key difference is that they are using a 1-to-1 model where you say which library you want to use and it joins the dots, whereas I believe you're trying to say "I don't know which one will be available but whatever one you find, go use it".
I don't think it's insane, but you might have some fun trying to work out which library to use, particularly if both are available.
Web development frameworks (Prototype, jQuery, etc.) themselves are designed to be abstractions on top of the various browsers that exist. You ask the framework to do one thing and it has the same result (ideally) regardless of the browser. So, here, you are proposing an abstraction on top of abstractions. Presumably because you want people to be able to use your tool regardless of what framework they have chosen for their site. While it sounds like an interesting idea, I would personally have to guess that it would not work out in the long run. Largely because you do not know what the future holds. Prototype used to be the number one use framework, now jQuery has surpassed it. Perhaps another one will be very popular in a year, what if you then want to support that framework? That can be a lot of conditional code that you have to add, and in addition, force being loaded into the browsers of those using your tool.
I say either pick a single framework to support and stick with it, or maintain separate libraries. Ideally, it would be really cool if you could write some sort of builder script. This would allow you to set framework rules in some list and the script would build separate scripts for each framework based on some core script and the rules list. I honestly am not sure how to best accomplish something like this but it would effectively give you that abstraction on abstraction power that you are looking for without it being visible to the end user.
I'm looking for a way to write a non-GUI bot using Mozilla Framework. The bot should be able to work like normal browser (automatically download relevant JS files, make XMLHTTPRequests, run JS operations, modify DOM), except no GUI will be needed.
I wonder if it is possbile to build XULRunner without X, GTK/KDE (without any GUI dependencies), as I will run the bot on FreeBSD server 6.4.
It may sound a bit weird but I need a bot with capacity to operate like browser, runs JS, modifies DOM, submit forms running on non-GUI environments.
I've looked into other browsers such as Lynx, Links, Hulahop, Chrome V8 engine, WebKit JavascriptCore but yet to find desirable output.
It's a part of school project, thesis. We will use to observe price change of budget airlines and after one year long data collection, we need to deduce pricing strategy and customer behavior. It is a serious Final Year Project.
Any hint or help is greatly appreciated! Thank you in advance!
Regards.
You should be able to make progress with selenium. It's a record/test/play tool but its core is manipulating the DOM.
Update from Grundlefleck's comment: As for launching the actual tests there is selenium remote-control, which allows you to write your tests in Java, Ruby, plain HTML and other possible drivers.
Yes, it is possible (but it might very well require LOTS of code changes).
No, I do not know any of the details.
I would not recommend this approach for your purposes. From your comment, it sounds like you are trying to scrape webpages. If you really need to use JavaScript, you can use a stand-alone JavaScript-engine (Mozilla's is available here). Otherwise, I would use Beautiful Soup with Python or Twill. You might also want to read this question.