vi - global search and replace?

I use vi heavily. Every time I have to do global search and replace, I have to do google search first. So documenting it here:

:%s/lookForMe/ReplaceWithMe/g

Subversion - query what files will be updated

Another subversion entry!
Before I push changes out to the production website, I wanted to see what files will get pushed out. So I wanted to see if I run svn update, which files will be updated. I was hoping to find something like 'svn update 'dry run'" or 'svn update -query'.

So I looked hard at 'svn update' documentation but still didn't find anything. After a few searches on the manual, the command turned out to be on the least expected svn command. So, the summary is - if you want to see what svn update will do, run this command:
svn status -u

subversion checksum mismatch problem

I got hit with the subversion checksum mismatch error again today. I had faced this problem couple of weeks ago, but just checked out a new copy to avoid fixing the problem at that time. Today I thought I would dig deeper.

I saw two variations:
svn: Checksum mismatch for 'aaa'; expected: 'xxxxx', actual: 'yyy'
And:
Checksum mismatch while updating

I did few searches, and found that people had fairly complex set of steps to fix this. A simpler solution suggested was to check out a clean copy of your files, and then copy over all your changed files from the problem copy to your new copy. This was also painful for me because I had changes all over my working copy, and not just in the problem directory.


After looking at the svn files I found that the easy solution that worked for me (still involved checkout) was to
1. checkout a clean copy
2. for new and your problem checkouts, go to the folder where your svn mismatch error is thrown
3. in that folder, go to .svn folder
4. copy the entries file over from the clean copy.
5. svn cleanup on the problem folder
6. svn update

phpUnderControl, CruiseControl and Jetty - No context on this server matched handled this request

I am tryin to get phpUnderControl set up, and for that I needed to get Cruisecontrol working.
I installed Cruisecontrol, set up phpUnderControl (there are enough instructions out there), but let me know if you want me to do a writeup)
After putting all pieces together in a VirtualHost, I go to cc.myserver.com and I get:
Error 404 - Not Found.
No context on this server matched or handled this request.

I looked around quite a bit, but didn't find the answer. Going to Jetty forums, finally, I pieced together that Jetty doesn’t get configured with a default context automatically. So here is what I did:
go to /opt/cruisecontrol (where I have cruisecontrol installed)
cd webapps
ln -s cruisecontrol root

Restart cruisecontrol and now cc.myserver.com loads the cruisecontrol nicely.

Ignoring svn entries in Cakephp

If you are trying to protect the svn related files so that they dont get shown in a browser, here is what worked for me after trying various things:

RewriteRule ^(.*/)*\.svn/(.*) - [F,L]

Making Cakephp and Shindig work together

So we decided to use Shindig for our web console widgets. There is lot of documentation on how to make shindig work as a virtualhost.

However, I didnt find complete documentation on how to make it work as a Alias (say www.domain.com/shindig/xxxx)
Where your Cakephp app runs at www.domain.com/

So basically, we have cakephp running as virtual host and our gadgets/widgets will be provided by shindig using the url www.domain.com/shindig/gadgets/ifr

Just few days ago, I read an interesting point in a performance article on Android code site - (paraphrasing) there are two phases of learning to developing on a new platform - first step is to make it work, second step is to make it work the right way.

So here is what I did and made it work - now you readers tell me how to make it work the right way.

I did svn co of Shindig in my downloads directory.
From there, I exported the following directories into vendors/shindig directory of my cake app.
- config
- features
- javascript
- php

So far so good.

In shindig/php/.htaccess file have the following line uncommented:
RewriteRule (.*) /shindig/index.php [L]

In shindig/php/config/container.php update as follows:
'web_prefix' => '/shindig',
'default_js_prefix' => '/shindig/gadgets/js/',
'default_iframe_prefix' => '/shindig/gadgets/ifr?',


In shidig/config/container.js, change all occurences of %host% with %host%/shindig. When I did it, there were 5 instances.

Now the shindig side is updated.

Next we need to tell Cakephp to ignore shindig urls. So, in your root .htaccess file
add
RewriteRule ^shindig/.*$ - [L]
Getting this to work took me a good part of the day. But hey, I now know how mod rewrite works, which I never bothered to learn till now.


Last part, we need to update the apache virtual host, so I added the following block:

Alias /shindig /dev/coolproduct/vendors/shindig/php
<Directory /dev/coolproduct/vendors/shindig/php>
</Directory>



Now, I put in a sample container and a widget, which I can load using:
http://local.domain.com/shindig/gadgets/files/coolappsamplecontainer/coolappsamplecontainer.html

IPhone development - Global variables in Objective C

This one took me few hours, so I hope this post saves someone time.

So while developing our app for iphone, I decided to use static variable (probably a bad design choice, but I wanted to get the concept working and fix the code later). Anyhow. I found that using global static variables in Objective-C is obvious, but only if you know what you are doing.

For a newbie like me, who skimmed the Objective-C manual, and did read that there is something called retain, forgot about it when I actually needed it.

The problem was that I was setting the value in one View, but it was showing up empty on the other side. To add insult to injury, the iphone simulator showed all kind of weird exceptions, which I could not find any explanation yet. For example, it was crashing without any clear explanation. In few times, I saw NSCRArray length selector being invalid as reason for crash.


So, to have a global variable, this is what I did that worked:

In Globals.h:
extern NSString *gProp;

In Globals.m:
NSString *gProp;

In ViewThatHasABigWidgetThatSetsThisGlobalViewController.m:
-(void)someMethod
{ gProp = [textFieldvalue retain]; }

In ViewThatUsesThisGlobalViewController.m:
-(void)someMethod
{ NSString *textFieldValue = gProp; }