DRYing HTML using content_for and helpers
by sylv3rblade on March 2, 2012
I recently encountered a scenario where I needed to dry up some HTML code for a navigation snippet that needed to appear on both the top and bottom of my main content. Here’s a snipped version of the code
<div class="tablenav top row">
<div class="somenavigationfunction"></div>
<div class="anotherfunction"></div>
<!--
Some code for the navigation here
-->
</div>
<div class="display row">
<!--
Main display page here
-->
</div>
<div class="tablenav bottom row">
<div class="somenavigationfunction"></div>
<div class="anotherfunction"></div>
<!--
Some code for the navigation here
-->
</div>
The code that I need repeated divs with tablenav classes. The usual way to go about this is using content_for and yield:
<% content_for :tablenav do %>
<div class="tablenav top row">
<div class="somenavigationfunction"></div>
<div class="anotherfunction"></div>
<!--
Some code for the navigation here
-->
</div>
<% yield :tablenav %>
<div class="display row">
<!--
Main display page here
-->
</div>
<% yield :tablenav %>
A bit DRY-er now right? The problem with this approach is that both instances of the yielded output sports the same set of classes. This is good most of the time but in my current usage, I need the top instance to use a “top” class while the bottom one needed a “bottom” class for proper padding. I could simply add another div to wrap each of the yield lines but that’s requires me to edit the css file to reflect the change. Here’s the solution I came up with using content_for and helpers:
<% content_for :tablenav do %>
<div class="tablenav top row">
<div class="somenavigationfunction"></div>
<div class="anotherfunction"></div>
<!--
Some code for the navigation here
-->
</div>
<%= nav_block("top") %>
<div class="display row">
<!--
Main display page here
-->
</div>
<%= nav_block("bottom") %>
And the code for the helper
def nav_block(location = nil, &block)
content_tag("div", content_for(:tablenav), :class => "tablenav #{location} row").html_safe
end
Just fire up the page in your browse and watch it work 
. Now how exactly did this works? Turns out that content_for can also be used to output it’s contents. If you’re wondering why yield wasn’t used is because it simply doesn’t work with helpers. If you tried to use yield, you’ll end up with the following LocalJumpError: no block given (yield).
Important Note: I’ve only tested this on Rails 3.x, Rails 3.2 to be exact.
Hope that helps.
[Linux] changing file or folder permission recursively
by sylv3rblade on February 19, 2012
I recently encountered a permissions problem when installing a new application on my Wiredtree VPS. The crux of the problem was some of the necessary files have the wrong access permission thereby rendering the application almost inoperable. To fix that, I needed to change permissions of a whole lot of files and folders. And while I could’ve changed the permissions individually, it would’ve taken quite a long time so here’s what I found to work
To set all the folders to 755:
find . -type d -exec chmod 755 {} \;
To set all files to 644:
find . -type f -exec chmod 644 {} \;
Let’s say you want to change the permissions of files that end only in .rb and set it to 755 (pattern escaped with slashes)
find . -name \*\.rb -exec chmod 644 {} \;
Simple right?
Leaving the current nest
by sylv3rblade on February 2, 2012
So yes. I finally made the decision to write THE letter.
I’ll be forwarding it to my superiors on the 15th and I’ll be signing my contract with the new company on Monday. More monies plox.
ArgumentError: invalid byte sequence in US-ASCII
by sylv3rblade on January 3, 2012
If you’re on Ruby 1.9.2 and have started getting this error when trying to install gems (either by gem install or bundle install), your environment is simply missing the LANG variable and is loading up US-ASCII by default.
To fix this, simply run the command below before installing anything
export LANG=en_US.UTF-8
or to make it more streamlined, add it to your .bashrc or zshrc (if you’re using the zsh shell).
Built a new PC over the holidays
by sylv3rblade on January 1, 2012
I was planning on saving things up for Ivy Bridge but seeing that it’s release date is around 6 months (or more) away, I decided to bite the bullet and splurge a bit to build a new gaming PC.
Here’s what I’ve bought to build my rig:
- Intel i5-2500K
- Asus P8P67-M B3
- G.Skill RipJaws 8gb (2x 4GB 1600Mhz) DDR3
- Seagate 500GB 7200 Sata 3
- Cooler Master V8 CPU Cooler
- Cooler Master Storm Enforcer
- AeroCool Strike-X 80PLUS 600W PSU
Total cost, around 30K Php
Why the i5-2500k? It’s the most popular CPU in Intel’s current Sandy Bridge line and with good reason. First off, it’s the cheapest unlocked processor, the next item on the list is the i7-2600K and while offers a bit of improvement over the 2500K, the added cost for me is simply not worth it.
My initial build had me going with the Asus P8P67-M B3–take note that I say initial because I’m going to replace it soon with a Z68 board (either an Intel one or another Asus board). Mind you if you’re looking for a cheap way to mount your Sandy Bridge processor, the P8P67-M is a good board, It’s got the basics laid down like support for 1600 Mhz DDR3 DIMMs, support for fairly large CPU cooler (in my case the Cooler Master V8), SATA 3 6Gb/s ports, USB3, etc. For my use case however, I’ll be better off going with a Z68 board due to Virtu, Intel’s multi-GPU solution implemented at board-level. Basically the gist of Virtu is that you’ll be using Sandy Bridge’s on-chip GPU until your applications demand something beefier. I’m still looking at reviews but I think my gist is spot on so correct me if I’m wrong as I’m basing this on a several weeks old review from Anandtech. Apparently I read things wrong, Virtu appears to be implemented on application level indicating that there will be a performance hit when you opt to use the IGP and discrete GPU at the same time :/ Darn.
I stuck with a Seagate 500GB 7200 because I still have my 1TB Seagate 10K Raptor which I’m currently using as my primary drive. I wanted to get an SSD for this but that’ll have to wait for my Ivy Bridge (??? hopefully haha) build.
Looking at the list, there’s no GPU from the things I’ve bought. I still have two DX10 GPUs which have served me well, the GeForce 460 GTX and the Radeon 4850 1GB SE. The current build uses the Nvidia card because I had stability issues with the 4850 :/ I’m still going to use for my HTPC once I have purchased the new Z68 board.
Now for the case, I opted for the Storm Enforcer because my first choice, the 690 II Advanced was sadly out of stock 
. Compared to my older case, the Thermaltake V3, the Storm Enforcer was a hell of a lot easier to work with due to it’s massive size and features. The price is well worth the looks too
I got the v8 and Strike-X PSU for kicks (admittedly it was an expensive choice >_> but it looks quite well with the case doesn’t it?).
Is it worth it?
In a word, yes.
My computer is now leagues faster than my older rig which was based on a Core 2 Duo processor and it feels a lot snappier than my 2011 Macbook Pro who’s performance is quite bottlenecked by the 5400 RPM drive (something I plan to remedy in the near future). In terms of games, I can play Metro 2033 on High (with a few tweaks) and Skyrim on Ultra at 1920 x 1080 resolution considerably well (with a quite a few dropped frames on areas with high particle count thanks to my video card and it’s limited bus :/). One of the best perks I’ve had is mirroring games on my 32 LCD TV so my “audience” can enjoy watching me play ).
My new build will be an i3-2100 HTPC/Fileserver which I plan to get this January to replace my Buffalo NAS.
Need moar coffee
by sylv3rblade on November 24, 2011
Sleep is a bit of a rare commodity for me these past few days :/
Must.
Get.
Sleep.
But I need to finish my projects.
Need.
Moar.
Coffee.
Back online yay!
by sylv3rblade on October 27, 2011
FINALLY!
I lost all hope of waiting for the host of my dev box to get things in line and bring back my development VPS from it’s infinite downtime so I said “screw it” and moved this blog back under my “blog” server at WiredTree and got myself a new VPS from Linode.
Hurrah!
From the get go, I LOOOOOOOVE Linode. Awesome ticket response time, awesome server spec for your money and best of all, I got a VPS in Tokyo (response time yay). Checkout their plans here [Protip: that's my referral link].
You can checkout the only project (for now at least) I have on my Linode VPS (Project Alter.. check it out here). Once I get things running smoothly (posting updates, not rolling out new code since that’s been optimized thanks to Capistrano), I’ll upload more projects onto it.
I am a bit miffed that they only support credit card payments as I have to manually deposit money onto my EON card to pay for it instead of simply getting paypal subscription to do it for me but hey, for the money I’m paying and the service I’m getting, it’s worth it. Yes, I could simply allow my EON card to draw funds from my Paypal account but I don’t like the extra charges.
In any case, I’m happy to get things back online. Now I need to go back to work on Project Alter
Installing XCache on a server with Cpanel
by sylv3rblade on May 3, 2011
Traffic on my VPS jumped over the past few weeks and I needed a better caching solution so I installed W3 Total Cache. It provided you the option of caching pages, databases queries, features an object cache and even allows you to configure a CDN to serve your files. Trouble is, my server only had eaccelerator installed and it wasn’t compiled to use object-caching. Instead of upgrading recompiling eaccelerator, I opted to install XCache on my CPanel-enabled VPS.
Here’s a complete guide on installing Xcache on Cpanel.
First get the latest sources for XCache. As of publishing this guide, it’s 1.3.1
cd /usr/src/ wget http://xcache.lighttpd.net/pub/Releases/1.3.1/xcache-1.3.1.tar.gz
After which, unarchive the source and cd into the directory
tar -xzvf xcache-1.3.1.tar.gz cd xcache-1.3.1
Time to configure the sources for the current PHP environment
[root@host xcache-1.3.1]# phpize Configuring for: PHP Api Version: 20041225 Zend Module Api No: 20060613 Zend Extension Api No: 220060519
Once you see the message above, XCache is ready to install.
./configure && make && make install
This will check for errors and run the installation script. Once complete, you should see this line:
Installing shared extensions: /usr/local/lib/php/extensions/no-debug-non-zts-20060613/
If like me, you have a different OPCode cache installed like eaccelerator, you need to comment any instances of these from your php.ini file. In my case it was
extension=eaccelerator.so eaccelerator.shm_size="16" eaccelerator.cache_dir="/tmp/eaccelerator" eaccelerator.enable="1" eaccelerator.optimizer="1" eaccelerator.check_mtime="1" eaccelerator.debug="0" eaccelerator.filter="" eaccelerator.shm_max="0" eaccelerator.shm_ttl="0" eaccelerator.shm_prune_period="0" eaccelerator.shm_only="0" eaccelerator.compress="1" eaccelerator.compress_level="9"
After that copy these into the php.ini. Note that these are the settings on my server. Tweak them as you need or please.
zend_extension="/usr/local/lib/php/extensions/no-debug-non-zts-20060613/xcache.so" [xcache.admin] xcache.admin.auth = off xcache.admin.enable_auth = off ; admin installation: http://xcache.lighttpd.net/wiki/InstallAdministration xcache.admin.user = "admin username" ;if you're going to use this xcache.admin.pass = "md5 hash of your password" ;change accordingly [xcache] xcache.shm_scheme = "mmap" ; to disable: xcache.size=0 ; to enable : xcache.size=64M etc (any size > 0) and your system mmap allows xcache.size = 128M ; set to cpu count (cat /proc/cpuinfo |grep -c processor) xcache.count = 4 ; just a hash hints, you can always store count(items) > slots xcache.slots = 8K ; ttl of the cache item, 0=forever xcache.ttl = 13300 xcache.cacher = On ; interval of gc scanning expired items, 0=no scan, other values is in seconds xcache.gc_interval = 0 ; same as aboves but for variable cache xcache.var_size = 2M xcache.var_count = 2 xcache.var_slots = 1K ; default ttl xcache.var_ttl = 3600 xcache.var_maxttl = 7200 xcache.var_gc_interval = 300 xcache.test = Off ; N/A for /dev/zero xcache.readonly_protection = Off ; for *nix, xcache.mmap_path is a file path, not directory. ; Use something like "/tmp/xcache" if you want to turn on ReadonlyProtection ; 2 group of php won't share the same /tmp/xcache ; for win32, xcache.mmap_path=anonymous map name, not file path xcache.mmap_path = "/dev/zero" ; leave it blank(disabled) or "/tmp/phpcore/" ; make sure it's writable by php (without checking open_basedir) xcache.coredump_directory = "" ; per request settings xcache.cacher = On xcache.stat = On xcache.optimizer = Off [xcache.coverager] ; per request settings ; enable coverage data collecting for xcache.coveragedump_directory and xcache_coverager_start/stop/get/clean() functions (will hurt executing performance) xcache.coverager = Off
After editing your PHP ini, type:
php -v
to check if things loaded properly. This is the output from my server:
[root@host xcache-1.3.1]# php -v
PHP 5.2.11 (cli) (built: Oct 27 2009 16:43:13)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2009 Zend Technologies
with XCache v1.3.1, Copyright (c) 2005-2010, by mOo
with the ionCube PHP Loader v3.3.20, Copyright (c) 2002-2010, by ionCube Ltd., and
with Zend Extension Manager v1.2.2, Copyright (c) 2003-2007, by Zend Technologies
with Zend Optimizer v3.3.3, Copyright (c) 1998-2007, by Zend Technologies
And you’re done. After which i simply set W3 Total Cache to use XCache for Database and Object Caching, flushed all existing caches and voila!
Just upgraded ;)
by sylv3rblade on April 19, 2011
I bit the bullet.
I’ve managed to complete a few projects this year which gave me enough money to sponsor the upgrade .
Yep it’s a costly upgrade (but I still have a few more things to get, like 2 SSDs, one for my older Core 2 13″ MBP and the new one) but it’s well worth every cent spent.
Read the rest of this entry »
cPanel error: httpd failed – A restart was attempted automagically
by sylv3rblade on April 10, 2011
While my recent server transfer has been smooth sailing, I did encounter one error that bugged the hell out of me.
At certain points of the day, I’d be receiving a notice that my VPS had it’s httpd process fail and restart automatically. A copy of the email is posted below:
httpd failed @ Sun Apr 10 07:07:09 2011.. A restart was attempted automagically.
Service Check Method: [tcp connect]Failure Reason: Unable to connect to port 80
After a quick bout of google-fu I found our that the server is exceeding the allowed number of connections Not good considering that the new server is quite powerful enough to handle more than it’s current peak traffic. Reading further into this, I had to execute this line:
grep MaxClients /usr/local/apache/logs/error_log
which then netted me this response:
WARNING: MaxClients of 512 exceeds ServerLimit value of 256 servers, lowering MaxClients to 256. To increase, please see the ServerLimit [Sat Apr 09 12:47:10 2011] [error] server reached MaxClients setting, consider raising the MaxClients setting
Soooo the problem is how apache is setup. The fix? Simply log in to cPanel and set the setting for MaxClients to something higher (in my case I doubled the number from 256 to 512) as well as he ServerLimit (to the same number). Of course if you want to do this manually, simply edit the MaxClients settings on apache’s httpd.conf file and restart the server.