Semi-static pages are used everywhere on websites. They’re those pages like an “About” page, which has content on it that doesn’t really change that often. Typically, a controller would have to house these actions (/about, /faq, /contact, etc.), and  the routes specified manually. Railscasts came up with an ingenious idea to create a controller which was routed to /static/*, so that semi-static pages could be created on-the-fly and modified easily. It also allows for modifications to change without committing to a repository and going through the process of deploying all over again.

For those needing a quick Rails primer before going on, here’s the quick and dirty of what you need to know to understand this:

• Rails is a MVC-based web application framework that runs on Ruby. In short, Ruby code is written to create webpages on-the-fly.
• Every request in Rails is first put through the routes file in config/routes.rb. This file tells Rails which Controller and Action is run.

Okay, let’s get started. Let’s create our static pages scaffold (which includes model, views, and the controller). Obviously, there are sections of this that you would want to require authentication for (editing and deleting, for example), but that’s outside the scope of this tutorial.

script/generate scaffold pages title:string permalink:string content:text;
rake db:migrate

Now we need to modify our controller slightly. More specifically, our show action. Right now, it will respond to showing an element only when the ID is displayed. We want to modify it to handle a permalink as well (/about and /contact look better than /pages/135, don’t you think?). Here is your modified show action:

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def show
  if params[:permalink]
    @page = Page.find_by_permalink(params[:permalink])
  else
    @page = Page.find(params[:id])
  end
end

Before we go any further, we need to create two custom methods in our model. These will format the permalink to remove any unwanted characters for the custom route name (replacing all unacceptable characters with an underscore) and for the URL (replacing all unacceptable characters with a forward slash to allow for nesting of pages). It’s also important to note here that previous validation should be done to ensure that the permalink does not have leading or tailing non-alphanumeric characters, but I removed that for simplicity’s sake.

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class Page < ActiveRecord::Base
  def route_name
    p = self.permalink.gsub(/([^A-Za-z0-9])+/, '_').downcase # Change non-alphanumeric characters to an underscore
    "static_#{p}"
  end
 
  def uri
    self.permalink.gsub(/([^A-Za-z0-9])+/, '/').downcase # Change non-alphanumeric characters to a forward slash
  end
end

At this point, we can create and modify our pages as we would regularly expect from a new controller. All of our pages are accessible via /pages/1, /pages/2 etc. We now need to make our controller act as our catch-all (so that all requests that do not match any of the other controllers get routed to our Pages controller), and we also need to provide permalink support. Finally, we will dynamically generate customized, name routes for all of our semi-static pages. All of that gets accomplished with a few short lines of code. Add the following code to the top of your config/routes.rb file, starting at line 2 (inside the ActionController::Routing::Routes.draw section):

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def map.static_page_actions
  pages = Page.find(:all)
  pages.each do |page|
    self.send("static_#{page.route_name}", "#{page.uri}", :controller => "Pages", :action => "show", :permalink => page.permalink)
  end
end

Finally, we need to call this method close to the bottom of the code, right before our default catch-all routes.

map.static_page_actions
map.connect ':controller/:action/:id'
map.connect ':controller/:action/:id.:format'

What this method does is retrieve all of the static pages in the database, then creates a customized, named route for each page, telling Rails what each URI should look like, and where to direct the request to.

Hopefully this helps some people out with their dynamic page creation. I’m pretty sure there’s a pitfall or two here, but I think it could be taken care of by doing some simple route housecleaning in the Pages CRUD controller. The perk of this option is that it allows the routes to be named, and hopefully that is of some benefit for others.

Next Monday, I have an interesting post for all of you with iPhones. One thing I really like about the iPhone is that I don’t have to delete text messages. I have a quick and free way for you to back up all of your text messages to read later on. There’s a lot of paid services out there to do it, but you don’t have to pay anyone for this quick-and-easy trick!

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Now, anyone that has been around two or more Linux command-line junkies I’m sure has heard the Emacs vs. ViM argument at some point. Regardless of which one you like, they’re both great editors. Give them both a shot and choose your favourite.

ViM Overview

Vim can be very overwhelming to start off on, but is great once you get used to it. When you first open ViM, you will be presented with a blank document and you will be in Normal mode (see below). Soon, we will be able to start writing text, undoing a mistake, perform cuts, copies, and pastes, as well as some search-and-replace.

A quick note that almost everything is case-sensitive!

Program Modes

There are six main program modes in ViM, listed below. We will only cover three of them in this tutorial for the time being.

• Normal Mode. This is where you type all of your commands, typically to move into one of the other modes.
• Insert Mode. Here is where you’ll actually type text into your document.
• Visual Mode. Visual mode is mainly used for yanking (copying) and deleting (cutting). Although it can do more than this, we’ll focus on these for now.
• Select Mode. Similar to Visual mode, Select mode is typically used for deleting a selection of text and immediately typing over top of it.
• Command-Line Mode. This is where you type your commands, such as saving, searching (and replacing), and the ability to edit ViM’s options.
• Ex Mode. All-in-all, this is pretty much command-line mode, except after typing a command you end up staying in command-line mode instead of reverting back to Normal mode.

Let’s Write Something!

You’ve just opened up ViM, but every time you try to type text, nothing seems to happen? What gives?! Well, right now you’re in Normal mode, and ViM is waiting for an instruction. In order to start typing text, just type “i” (for “Insert”) or “a” (for “Append”). The Append mode will move your cursor one character forward before you can type, so keep note of that. After you’re finished typing what you want, just hit Escape to get back into Normal mode.

Let’s say, that you just wrote “ViM is awesome!” in your spiffy new document, but saying it once just isn’t enough! You want to say it over and over again, but typing it out so many times just seems like a waste, doesn’t it? Time to go into Visual mode! Move your cursor to the beginning of your text using the cursors, then type “v” (lower-case). This puts you into Character-Select Visual mode. Move your cursor to the end of the text, and press “y” (for “Yank”), which copies the text into it’s built-in clipboard. Move your cursor to where you want to paste, and type “p” (for “Paste”). Note that “P” will paste BEFORE your cursor, so keep that in mind.

Fixing Screw-ups

Whoops! You pasted it one-too-many times, or you pasted it in the wrong spot! Never fear, the Undo tool is here! Make sure you’re in Normal mode (just hit Escape if you’re not sure), and press “u” (for “Undo”).

What if, for example, you ended up typing “ViM is awsemoe!” (hey, your fingers got tied up; it happens). It doesn’t make sense to undo all of that, so let’s just do a search-and-replace. Go into normal mode and type “:%s/awsemoe!/awesome!”, then hit enter. Poof! Problem solved! I’ll discuss the search-replace a bit more in the cheat sheet. If you just want to search for text, type “/your-text-here” in Normal mode, then hit enter. “n” will move you forward through all the findings, and “N” will move you backwards.

Saving and Exiting

Saving and exiting is really easy. “:w myfile.txt” will write the file to myfile.txt. If you opened an existing file, you don’t need the file name, so “:w” is all you need. To do a save and quit at the same time, type “:wq”.

What if you want to quit but don’t save your changes? The best way to do this is “:q!”, which will quit without heeding any warnings about the file not being saved.

Command Quick-Review

- a - Append
- i - Insert
- /<your-text-here> - Search for <your-text-here>. Does NOT use regular
  expressions
- dd - Delete the entire line that your cursor is on
- x - Delete the character your cursor is hovering on.
- :42 - Move to line 42
- G - Go to the last line in the document
- :s%/<search>/<replace> - Regular expression-compatible search-replace.
    - :s/<search>/<replace>/g - Same as above, except replaces everything on a
      single line. Remove the "g" to replace only the first occurrance.
    - :s42/<search>/<replace>/g - Same as above, except replace on line 42.
- V - Line-select Visual mode
- v - Character-select Visual mode
    - y - Copy (yank) the selected text
    - d - Delete the selected text
- :w - Write the file to disk
- :wq - Write and quit
- :q - Quit
- :q! - Quit without saving

A lot has happened since I last talked about the IPAM presentation that I took part in. To start with the related topic, I was approached to do the presentation again, this time internally to other departments. Thus, the other co-op student and I set about cleaning up the presentation a bit, fixing some errors, and making it flow smoother. It went much better the second time, thankfully, both from a public speaking perspective and a demonstration perspective. As fun as it was to work on that, I’m glad it’s over and done with right now.

Speaking of work, the number of days that I have left at IPC are dwindling quickly as the new year approaches. I work until December 31st, at which point I’m back in class. It’s been a fun past couple of months, and the paychecks have been very nice, but I’m also looking forward to getting back on campus to get some more studying done. I’ve decided that I won’t get a job during the winter semester so I can concentrate on my studying; I’ll have more than enough money to get through four months, and then I’ll be working in the summer again.

After that presentation was done with at work, I found that I had a fair amount of spare time, as there weren’t too many tasks to work on. I spent that time learning Ruby on Rails, and putting that knowledge towards the new UMSwing site. Although on the outside it will look almost the same as before, this new site will have an extensive backend that will make UMSwing virtually paperless. Although you may not think we use that much paper, think again; I have a full 3″ 3-ring binder in our office that says otherwise. All of our memberships, attendance, and transactions will be tracked on the web application, thus eliminating the need for those pieces of paper to be printed in the first place. Anyways, I’ve been working very hard on the site, and it’s almost ready to be tested by some other people. So, if you’re interested in testing some software for an eco-friendly cause, let me know in the comments section and I’ll keep you informed.

That’s a quick update on what’s happened in the past few weeks at work. I have a few more updates to spew out in the coming days, one of them involving my server upgrade (*cough* RAID *cough*), and some involving some extra-curricular activities (including some new photos to go up soon).

I have three culprits to lay the blame for this lack of updates. One of those has been a savage case of writer’s block. Another of those has been a very busy schedule for me. Busier than normal, even. As such, the third and final culprit goes by the name of “Sleep Deprivation”, which always seems to tag along with culprit number two. In a possibly vain attempt to get myself back on my writing pedestal, I figured I’d fill you all in about the past two weeks.

As those of you who are involved in the Winnipeg swing scene may know, UMSwing had two events to demo at last weekend, the first being the Gilbert & Sullivan Gala Fund-raiser, and the second being the Winnipeg Jazz Orchestra’s performance. The fund-raiser involved a couple of demonstration songs, and the WJO performance involved dancing for 20 minutes during their intermission, as well as the opportunity for one or two couples to dance on stage during one of their songs. Although they took place over the weekend, I’ve been in talks with organizers of both events for quite some time, and the last week became crunch time for me as I made sure everything went as expected. I’m really glad that we were invited to both events, and we’d certainly be interested in doing it again.

To swing (no pun intended) from one quirky interest to another, this Wednesday a couple of us took advantage of the day off and planned for a session of Dungeons & Dragons. I need to take a minute here to explain this:

• No, it did NOT die out ten years ago
• Yes, it IS fun
• No, you do NOT need to be an über-nerd to play
• Yes, girls DO play it.

Anyway, in this group (which has yet to receive a name), I am the DM; I’m the one who tells the story, plays the non-player characters (NPCs), and guides the other players through their adventures. Although very fun to DM, it also requires a lot of work to create your own adventures; dungeons, the global map, encounters, and NPCs all need to be planned. Thus, that chewed through a fair amount of spare time that I had. On the plus side, I over-prepared, so I have everything I need for the next time around.

This weekend, I have plans to go out to a friend’s cottage for some much-needed rest. It’ll be nice to get away from it all, and hopefully take some great photos, which I hope to put up for Monday’s post. I also have some ideas for another Linux command line tip, so those of you reading my previous post regarding Byobu: stay tuned.

“I’ve never seen you here before. I like that in a woman.”
– Renaldo ‘The Heel’, Crimewave (1985)

As always, I welcome your feedback; just post a comment below!

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But I digest

While casually browsing the rewards catalog online, I was going through the gift cards and subscriptions. I happened to notice a new section for charities. Under there, you have redeem 170 Air Miles to donate $20 to one of three charities: Kids Help Phone, Special Olympics Canada, and the World Wildlife Fund. Unfortunately, Air Miles has yet to add any more charities, but I sincerely hope that they add more than those three. I’ve made a firm decision to redeem a donation for every item I redeem on there.

I’ve never seen this on a rewards site, and I think it’s a great thing to do. Think about how many reward miles you have. When was the last time you redeemed them? Do you think you could spare a few to help a good cause? I hope the answer is yes. Some people don’t donate to charities because they can’t afford it. Now that you can use Air Miles, this should make things a little easier. Alternatively, redeem a gift certificate somewhere you would normally shop, and use the saved money to a charity of your choice. Either way, it’s a free donation.

Just a little food for thought.

Opening up my email, I notice the vulnerability in my inbox, and a message attached asking me to find all the servers in the government which might be vulnerable to this exploit. Now, as you can imagine, it’s not like there’s 50 servers in the government. This isn’t a situation where you go to each server manually and check for the vulnerability. This worked out to be a perfect situation to use nmap.

Nmap, as I had mentioned last post, is a security scanner. It’s powerful: really, REALLY powerful. There’s so many command line switches that they have to use two characters for a lot of them, and they’re case sensitive as well. To top it all off, it also provides scripting support. In layman’s terms, you tell it to jump, and it asks you how high, how many flips it should do, what music should be playing in the background, and what the acrobat’s costumes should look like. You get the picture.

Anyways, the task was put before me to determine which servers were vulnerable, and how many FTP services could simply be turned off. After acquiring a list of IP addresses of assets, I sorted the list, changed each IP to refer to the class C subnet (255.255.255.0 or /24), and remove duplicates. I then came up with a list of IPs which had an FTP service. Some had closed ports, and others were filtered. Some of them were also open. A few quick grep commands and I had narrowed down the list to open Windows boxes. Below, I have the nmap command that I used to find all the servers with FTP running on them. I’d be curious to see if anyone has come up with a similar command that might be useful for this same purpose, and where improvements can be made.

./nmap -T4 -PS21 -p21 -O --max-rtt-timeout 200 --initial-rtt-timeout 150 --min-hostgroup 100 -oG /tmp/WindowsFTP.grep -iL ../WindowsServers24

This might seem like an odd topic for a geek to discuss. After all, I’m supposed to be glued to my computer, make obtuse references to nerdy shows and movies, and have a natural inability to talk to women. While all of the above may or may not be true (heh), I also found myself two years ago to have an interest in swing dancing, thanks to a friend who convinced me to go to the University of Manitoba Swing Dance Club (UMSwing) open house (thanks Jacklynn!). Although initially I didn’t think I would enjoy it that much, I found myself addicted by the end of that open house, and walked out that night with a full membership. I’m still shocked that I’m even capable of dancing, but regardless, it’s a great way to get some exercise, meet new people, and get out of the house.

Two years later, and I’m on the executive committee for UMSwing as their omnipotent web administrator. I’ve met a lot of great people through the club, and by being on the executive committee, I can hopefully give back to a club which has helped me a lot. One of the events that is happening in just over a week is this semester’s open house, which I will be MCing. The club puts on one open house per semester, usually within the first few weeks. We pride ourselves on being able to teach anybody to dance, regardless of skill level. You don’t need to bring a partner to dance with, and you don’t need experience. We do some demos, teach you basic Jive, and do some social dancing. Oh yeah, and there’s a bunch of prizes that we will give away.

• Multi-Purpose Room (MPR), 2nd Floor University Center, University of Manitoba
• September 16, 2009 @ 7:00pm – 11:00pm
• Free!
• Prizes!
• No experience required!
• No partner required!

So, if you have nothing to do that night, come out and enjoy yourself.

UMSwing’s classes tend to be geared towards beginner swing dance. If you happen to have swing experience, HepCat Studio is a swing studio that is starting up today at 6:00pm. The first class today is free, and they will teach both beginner and intermediate swing dancing. You can find their website over at http://www.winnipegswing.com.

So, I will continue with random technological rants and whatnot next Friday. Methinks that my next post will probably discuss my upcoming server build and the parts involved. Although I had posted on it a while back, I’ve solidified my decisions for the next server incarnation. It will be awesome. Very, very awesome.

Although I already did accent lighting, I’d like to look at expanding it a little more. I had previously mentioned that I was going to add more neon lighting, but I’m also going to look into lighting up the running boards. Although my car is a red/maroon and my neon lighting is blue, I think I’m going to go with red LEDs along the boards; red and blue accent lighting together should look pretty nice. Since LEDs tend to run at an optimum voltage of 2.5 volts, I can get about 5 in every series, since a car runs on 12 volts. I’d like those to turn on when the doors open. Since they will be wired in with the door light, I can force them to turn on just like if I wanted the door light to turn on. I would also like to replace the door light, glove compartment light, and dashboard lights with LEDs (blue, white, and white respectively).

For exterior lighting, I’d like to also replace those with LED lights. They’re much brighter than conventional bulbs and use less electricity, which in turn improves fuel efficiency. Although I’m not sure about the headlights, I’m sure I can replace all of the other bulbs, and potentially make the enclosures clear, since the bulbs will be colored the proper colors. I’d like to get nice headlights as well, but I don’t know if they’re available for my car. But, if I can find ones that fit, I can take them out when I get a new car, and if they don’t fit I can sell them and get part of my money back since they last forever.

The last thing I’d like to look into is redoing the upholstery. The seats are boring and bland, but the front ones are an irregular shape, which may make finding seat covers difficult. I already found a faux-leather seat cover for the back bench seat which will look nice, and I also picked out black-with-red seat covers for the front seat, pending that they’ll actually fit. If it proves to be difficult, I might end up doing alterations to them with a sewing machine.

And thus completes my plans for my car. Since it didn’t cost me anything and it’s not exactly new, I think it’s a reasonable time to try a few things out and see what works and what doesn’t. That way, when I get a nice car, I can do some customization on it and not be worried about destroying something.