1. Cape Town Ruby Brigade
Lightning Talks!

2. Schedule
● Farrel Lifson
● Luke Randall
● Glenn Roberts
● John Anderson
● Marc Helligers
● Dave Ungerer
● YOU!(?)

3. Cape Town Ruby Brigade
●
Meet 2nd Wednesday of the Month
● 19:00
● At the Bandwidth Barn
“Just like Rubyfuza, except there's only one
talk, 1/10 of the people but yet the same
amount of drinking”

4. Cape Town Ruby Brigade
●
9th March
●
13th April - “Sinatra” - Clive Crous
●
11th May
●
9th June
●
13th July
●
10th August
●
14th September
●
12th October
●
9th November

5. to_s & inspect: Wherefore art thou?
Farrel Lifson
farrel.lifson@aimred.com
http://www.aimred.com

6. inspect & to_s
Used to display an object

7. inspect & to_s
inspect - IRb/Console
to_s – Everywhere else

8. to_s
● What? Convert to a string
● Why? To represent or label an object
● Where? In a textual context
● How? By leaving out almost all detail
Remember it's a label not a data dump!

9. to_s
● Person class with name, surname, DOB,
earnings, address, etc etc etc.
● to_s should leave out 98% of data because it's
not needed to represent the person!
def to_s
“#{ name } #{ surname }”
end

10. to_s
Dear <%= @person %>
<%= select(:person, @people.map{|p| [p, p.id]})%>
In the “standard” context a string representation of
a Person is their name.

11. inspect
> brands = Brand.all
=> [#<Brand id: 9, client_id: 8, name: "15 on
Orange", benchmark_standards_score: 90,
benchmark_satisfaction_score: 90,
required_report_writing_grading: "A",
required_demographic: "A", active: true,
created_at: "2010-05-26 13:37:04", updated_at:
"2010-05-26 13:37:04", visit_type_id: nil,
report_template_code: 1, turnaround_time: 2>,
#<Brand id: 4, client_id: 4, name: "Cape Town
Tourism", benchmark_standards_score: 80,
??????????
benchmark_satisfaction_score: 80,
required_report_writing_grading: "D"

12. inspect
● What? Convert to a string!
● Why? To represent or label an object
● Where? In a debugging/informative context!
● How? By leaving out most detail!
Label and identify the object.

13. inspect
def inspect
“#{ self }(#{ self.id })”
end
>Brand.all
=> [Nandos(9), KFC(4)]
Representation is good enough!

14. Inspect & collections
> t = TemperatureMonitor.find_by_geocode(“CPTN”)
=> Temperature Monitor: Cape Town
Latt: -33.96 Long: 18.59 Alt: 42m
Last 5 temperature readings(51 total):
17/9/2008: 18C
18/9/2008: 23C
19/9/2008: 22C
20/9/2008: 16C
21/9/2008: 15C
> t.readings.last
=> 17/5/2006: 17C

15. inspect
>Area.new(:area_desc => "Cape Town",
:geocodes => "CPTN" )
=>
.---------------------------.
|AREA |
|---------------------------|
|Area Description: Cape Town|
|Geocodes: ["CPTN"] |
'---------------------------'

16. Limitations & Considerations
● to_s
– short
– single line
● inspect
– 80x25 screen
– Be wary of collections