BS Blogs

Developer, Hacker and Entrepreneur at heart. Interested primarily in creating consumer products and converting ideas into reality. Graduated from PENN with a masters degree and cofounded Lokalty right after. Currently cofounder at Partcle.

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When creating a custom initialiser for UIViewController (Rubymotion)

Always make sure to return self at the end of the initializer function. For ex:

class MapViewController < UIViewController

  attr_accessor :lat,:lng

  def initWithCoord(params={})

    self.lat = params[:lat]

    self.lng = params[:lng]

    self #important!

  end

end

Not doing this will give you a runtime error NSInvalidArgumentException

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getting FB-ios-sdk to work with rubymotion

I faced one of the most annoying bugs while trying to get Facebook Connect to work on a rubymotion app. I was able to get a sample facebook connect app working thanks to this github project https://github.com/Bodacious/FacbookConnectWithRubyMotion

The app was working perfectly as a stand-alone fb-connect app, but the moment I copied over the code into my main project, I was getting errors like 

uninitialized constant FBSession (NameError)

Believe it or not - the fix was to delete the Pods folder entirely and do a rake command, which regenerates the folder and the files within and voila it worked!! One of the most frustrating bugs encountered. Period.

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Cocoa Error 3840

If you see this kinda error while developing an IOS app (rubymotion in this case): 

(Cocoa error 3840.)" (Invalid value around character 0.) UserInfo=0xab7b760 {NSDebugDescription=Invalid value around character 0.} (BubbleWrap::JSON::ParserError)

Check your server to see if it is alive and kicking

Double check your data format, is it RTF?

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delayed jobs and scripts

Today I was facing a rather annoying issue with delayed jobs in rails. I had previously worked with them and as far as I remembered, they were really easy to get working. 

The difference this time: I was running a library script (which I had placed in the root lib directory) in my rails application. I was loading the files above the class structure and trying to get delayed jobs to work as follows:

Dir[File.expand_path(Rails.root.join 'lib/parse_scripts','**','*.rb')].each {|f| require f}

class Api::V1::PostsController < ApplicationController

.......

.......

 ParseScripts.delay.scrape

This was correctly inserting a delayed job entry into my table. But after a bit, I realized that it was silently failing and deleting itself automatically from the table (An issue that was mentioned in the delayed job wiki). The reason being, the delayed job script has no idea about my ParseScripts module which was not being loaded in the current environment! 

Hence, the fix was to require the module files as a rails initializer (config/initializers/load_scripts.rb) so that it was available to the delayed job script as well. And voila! everything works as normal again :)

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Single Table Inheritance in rails

STI - used in the case when 2 or more models are very similar in nature but have couple of attributes different. There has to be a main model (Eg: Posts) from where all the other models inherit (Eg: RecurringPost). 

There needs to be a type attribute in Post which will determine the type of the post.

class Post < ActiveRecord::Base

attr_accessible :type

end

class RecurringPost < Post

end

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Setting up a development machine

Install OSX command line tools

Install homebrew

brew doctor

brew install rbenv

rbenv global 1.9.3-p327

rbenv rehash

make sure rbenv path is included in bash_profile

brew install mysql

sudo gem install rails

[inothernews]

In which the Catholic Church uses science to debunk a myth and Hell has not frozen over.

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Haha so true

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An interesting take on hollywood bollywood

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my date with postgresql

I finally got the time to install postgresql - mostly as a requirement from heroku (they do not support mysql). Here were the steps:

brew install postgresql

initdb /usr/local/var/postgres

postgres -D /usr/local/var/postgres to start the server

make sure that your bash_profile (depending on your terminal) is loaded and also the PATH should contain /usr/local/bin:    export PATH=/usr/local/bin:$PATH

make sure to restart your terminal or do source ~/.bash_profile

Reinstall the pg gem if it has already been installed so that it relates to the latest installation.

do a rake db:create:all to create your rails databases.

Check out this screen cast by ryan bates to see how to migrate data from an old mysql db to postgresql http://railscasts.com/episodes/342-migrating-to-postgresql