Rails3 'link_to' displays literal HTML on front end

In the last month, I have been working on a rails3 app and I ran across this interesting problem where I need to create a href link to a another page from my current page.

In my view i have written

<%= "Please click on this link #{link_to('here', new_house_path)}" %>

And interestingly this is displayed as

Please click on this link <a href="http://localhost:3000/houses/new">here</a>

on the front end.

Hours of frustration and google searches leads me to doing this:

<%= ("Please click on this link #{link_to('here', new_house_path)}").html_safe %>;

which then is displayed correctly on front end

Please click on this link here

if that isnt clear enough, the trick is you need to wrap the string with a 'html_safe' method

Off i go to learn more stuff .....

Installing mysql on snow leopard

I have always struggled with install mysql on my snow leopard, as a result i have decided to keep a link on this blog for this:

http://www.icoretech.org/2009/08/install-mysql-and-mysql-ruby-gem-on-snow-leopard-64-bit/


Hopefully that link would be up for a very long time and i hope it is useful for someone else as well.

Watir: Search for elements on page using multiple attributes

I ran into a situation today where i wanted to scan through a page and return a table based on the table matching 3 attributes

Before:

browser.tables.find do |table|
table.class_name == 'my_class_name' and
table.cell(:class, 'class_1_name').text == 'some_text_1' and
table.cell(:class, 'class_2_name').text == 'some_text_2'
end

This was taking about 3minutes as there were about 86tables on this page under test. I was worried but the tables on this page was gonna increase with time which meant the time for this stage of the test was bound to increase.

In my search for how to search for a single table using multiple attributes:

I found this:

After:

browser.table(:class => 'my_class_name', :text => /#{'some_text_1}/, :text => /#{'some_text_2}/)

Believe it or not, i got my test time reduced to 3secs, awesome isnt it?

Enjoy!!!!!!

Implement 'Select column_name from table_name where condition' in Active Record

I need an array from the data contained in a particular database column based on a condition, so i get the array of active record rows:

array_of_rows = TableName.find(:all, :conditions => {:column_name => ['col_data1','col_data2']})

Then use the array map! function to replace the active record objects with the column_name value
array_of_rows.map!{|item| item.column_name}

Doing some search got me:

array_of_rows = TableName .find(:all,:select=>'column_name' :conditions => {:column_name => ['col_data1','col_data2']}).map(&:column_name)

And i like this better, concise ....
update:

I've had to update the active record query above by removing the :select option

array_of_rows = TableName .find(:all, :conditions => {:column_name => ['col_data1','col_data2']}).map(&:column_name)

This is because if i have a method

def find_some_data
TableName .find(:all,:select=>'column_name' :conditions => {:column_name => ['col_data1','col_data2']})
end

I am able to do:

find_some_data.map(&:column_name)

but i cannot do

find_some_data.map(&:another_column_name)

throws: missing attribute: another_column_name (ActiveRecord::MissingAttributeError)

because i have only retrieved 'column_name' values from the table

In other to be able to create any array composed of data from any column_name, i have

def find_some_data
TableName .find(:all, :conditions => {:column_name => ['col_data1','col_data2']})
end

Active Record find by Column Name

In recent days been doing a lot of ruby, which means i tend to use Active Record as well.

I had written some scripts where i was selecting records that matched a criteria such as:

@table1.table2s.select{|e| e.column_name == 1234}

but as i need to sort my result and also give some more conditions to filter the data, i need alternatives to this above query and i ended up with the two lines of code below:

@table1.table2s.find(:all, :conditions => {:column_name => 1234})
@table1.table2s.find_all_by_column_name(1234)

Please note that the two lines above does same thing, the second one is just a lil but shorter and more readable the the 1st one.

using the second one i can now do stuff like

@table1.table2s.find_all_by_column_name(1234, :order => "col_2 ASC")

which would order my results based on the column that i have specified and i could have ASC - ascending and DESC - descending.

I have learnt something else today .... Have you?

Blank cells in step tables in cucumber 0.3.11 is represented as nil

In my current job, I have been doing a lot of acceptance test using Cucumber, Watir and RSpec, obvious all in Ruby. I have been using Cucumber 0.6.x, in which blank cells in the step table are represented by empty string (""). This was okay for me until today when i had to use a previous version of Cucumber 0.3.11 due to reasons including compatibility with other projects in the CI build. And my tests start failing because blank cells are represented as nil.

There was fix put in the current release of cucumber to change blanks to be represented as empty and not as nil(for whatever reason, which i don't really care, as both nil and "" has got its own arguments.)

Some code to explain this, Assuming i have a step table as below:

Given that i have the following detail in my app
|Header1|Header2|Header3|Header4|
|Body1 |Body2 |Body3 | |

Notice that the last column of the second row is blank, this would be represented as nil in cucumber 0.3.11 while it is represented as empty string "" in cucumber 0.6.x

In my step definition file, I have fixed this by converting every nil value to empty ("")

Given /have the following detail/ do |table|
table.rows.each do |row|
row.map! {|value| convert_nil_to_empty_string(value)}
# do some other stuff with row as every nil object has been converted to empty string
# The map! method for Array, allow you to invoke the block for the array and it amends
# the existing array
end
end

The method which i call to convert nil to empty is below:

def convert_nil_to_empty_string(test_string)
if (test_string.nil?)
return ""
else
return test_string
end
end

There might have been a better way to do this but this surely worked for me in this scenario and the reason i decided to use a method was that the map! method would only allow me use the variable "value" only once in the block. I am sure there are some rubyist out there, that could advice me on some shorthand for this ....... Hope it helps you too