Sha256: 00dbab8d7c83f3a68958f46c085a89e8e4f70e2a621263e0c68f963e85d7fc09
Contents?: true
Size: 1.54 KB
Versions: 13
Compression:
Stored size: 1.54 KB
Contents
# Ovto::State
`Ovto::State` is like a hash, but members are accessible with name rather than `[]`.
## Example
```rb
class State < Ovto::State
item :foo
item :bar
end
state = State.new(foo: 1, bar: 2)
state.foo #=> 1
state.bar #=> 2
```
## Default value
```rb
class State < Ovto::State
item :foo, default: 1
item :bar, default: 2
end
state = State.new
state.foo #=> 1
state.bar #=> 2
```
## Immutable
State objects are immutable. i.e. you cannot update value of a key. Instead, use `State#merge`.
```rb
state = State.new(foo: 1, bar: 2)
new_state = state.merge(bar: 3)
new_state.foo #=> 1
new_state.bar #=> 3
```
## Nesting state
For practical apps, you can nest State like this.
```rb
class Book < Ovto::State
item :title
item :author
end
class State < Ovto::State
item :books, []
end
book = Book.new('Hello world', 'taro')
state = State.new(books: [book])
```
## Defining instance methods of state
You can define instance methods of state.
```rb
class Book < Ovto::State
item :title
item :author
def to_text
"#{self.title} (#{self.author})"
end
end
book = Book.new('Hello world', 'taro')
book.to_text #=> "Hello world (taro)"
```
## Defining class methods of state
Ovto does not have a class like `StateList`. Just use Array to represent a list of state.
You can define class methods to manipulate a list of state.
```rb
class Book < Ovto::State
item :title
item :author
def self.of_author(books, author)
books.select{|x| x.author == author}
end
end
# Example
taro_books = Book.of_author(books, "taro")
```
Version data entries
13 entries across 13 versions & 1 rubygems