Workshop description for https://github.com/DanyMariaLee/partyplanner

1. with Scala
Let’s plan a party
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

2. github.com/DanyMariaLee/
partyplanner

3. The task
Parse data Calculate Print result
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

4. use worksheet
or
REPL

5. google it

6. Try again

7. Data models
case class Price(product: String,
value: Double)
Price("cola", 1.5)
case class Consumption(product: String,
value: Double)
Consumption("cake", 0.01)
case class Party(name: String,
products: List[String])
Party("birthday", List("cake", "balloon"))
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

8. Request
case class Request(party: Party,
numberOfPeople: Int,
budget: Double)
Request(
Party("birthday", List("cake",
"balloon")),
10, 100.5)
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

9. Receipt
case class Receipt(request: Request,
totalAmount: Double)
Receipt(
Request(
Party("Party name", List("product")),
3, 100.0), 6.0)
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

10. Parse data
package partyplanner.utils
/**
* @return List[String] containing lines from file with `name`
* For example for file name.txt
*
* product1;value1
* product2;value2
* product3;value3
*
* result will be
*
* List("product1;value1", "product2;value2", "product3;value3")
*
* @param name Is the name of a file you want to read (e.g. "price.txt")
*/
def loadDataFromFile(name: String): List[String] = {
val stream: InputStream = getClass.getResourceAsStream(name)
scala.io.Source.fromInputStream(stream).getLines.toList
}
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

11. Parse data
import utils.Utils.loadDataFromFile
All data is in resources folder: party.txt, price.txt, consumption.txt
Use `split` function
val arr = "boo:and:foo".split(":") // results to Array("boo", "and", "foo")
Access each element by index
arr(0) // results to "boo"
Don't forget to transform String into Double type when necessary
"2".toDouble // 2: Double
"a".toDouble // throws an Exception
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

12. price.txt
/**
* @return List[Price] containing prices from file in resource
* For example for line
*
* "apple;1.5"
*
* price should be Price("apple", 1.5)
*/
def parsePrices: List[Price] = ???
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

13. price.txt
banana;2
coffee;1
Price("banana", 2)
Price("coffee", 1)
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

14. consumption.txt
/**
* @return List[Consumption] containing
* consumptions from file in resource
* For example for line
*
* "apple;0.5"
*
* consumption should be Consumption("apple", 0.5)
*/
def parseConsumptions: List[Consumption] = ???
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

15. consumption.txt
banana;0.2
coffee;0.5
Consumption("banana", 0.2)
Consumption("coffee", 0.5)
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

16. party.txt
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence
/**
* @return List[Party] containing Party from file in resource
* For example for lines
*
* "birthday;coffee"
* "birthday;cola"
*
* party should be Party("birthday", List("coffee", "cola"))
*/
def parseParties: List[Party] = ???

17. party.txt
birthday;banana
birthday;coffee
corporate;vine
corporate;fish
Party(“birthday", List(“coffee”, "coffee"))
Party(“corporate", List(“vine”, “fish"))
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

18. Run test
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19. Calculation
ONE product
for
ONE person
ALL products
for
ONE person
Total amount
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

20. ONE product
for
ONE person
consumption * price = product amount
Price("coffee", 1)Consumption("banana", 0.2)
C * P = A (product, person)
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

21. ALL products
for
ONE person
A1 + A2 + A3 + … + An = A(person)
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

22. Total amount
A(person) * number of people = total amount
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

23. Console dialog
party type
number of people
budget
Request
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence

24. Console dialog
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence
To get data from console we have
scala.io.StdIn object with methods for each type.
For example to get an Int
scala.io.StdIn.readInt()
! This method throws an exception if
user types a wrong type.

25. Console dialog
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence
Hey there, it's a party planner app!
We are offering different types of parties:
0 - birthday
1 - cocktail
2 - garden
3 - corporate
Please, pick the type of your party
Please, pick the type of your party
0
How many people will be at the party?
10
What is your budget for this party?
1000

26. Receipt
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence
--------------------
Birthday party for 10 people
cake
balloon
cola
icecream
banana
TOTAL $37.0
--------------------
THANK YOU!
10 February 2018

27. Contact me
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twitter @besseifunction

28. Thank you!
© 2018 The Quantium Group Pty Ltd. In Commercial Confidence