Class: Browser::Storage

Inherits:
Object show all
Includes:
Enumerable
Defined in:
opal/browser/storage.rb

Overview

TODO:

remove method_defined? checks when require order is fixed

A Storage allows you to store data across page loads and browser restarts.

Compatibility

The compatibility layer will try various implementations in the following order.

See Also:

Direct Known Subclasses

SessionStorage

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(window, name) ⇒ Storage

Create a new storage on the given window with the given name.

Parameters:

  • window (native) —

    the window to save the storage to

  • name (String) —

    the name to use to discern different storages



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# File 'opal/browser/storage.rb', line 39

def initialize(window, name)
  super()

  @window = window
  @name   = name
  @data   = {}

  autosave!
  reload
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*args, &block) ⇒ Object 



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# File 'opal/browser/storage.rb', line 81

def method_missing(*args, &block)
  @data.__send__(*args, &block)
end

Instance Attribute Details

#name ⇒ String (readonly)

Returns the name of the storage.

Returns:

  • (String) —

    the name of the storage



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# File 'opal/browser/storage.rb', line 33

def name
  @name
end

Class Method Details

.json_create(data) ⇒ Object 



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# File 'opal/browser/storage.rb', line 23

def self.json_create(data)
  data.delete(JSON.create_id)

  Hash[data.map {|key, value|
    [JSON.parse(key), value]
  }]
end

Instance Method Details

#[]=(key, value) ⇒ Object

Set a value in the storage.



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# File 'opal/browser/storage.rb', line 86

def []=(key, value)
  @data[key] = value

  save if autosave?
end

#autosave! ⇒ Object

Enable autosaving.



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# File 'opal/browser/storage.rb', line 59

def autosave!
  @autosave = true
end

#autosave? ⇒ Boolean

Check if autosaving is enabled.

When autosaving is enabled the Browser::Storage is saved every time a change is made, otherwise you'll have to save it manually yourself.

Returns:

  • (Boolean) 


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# File 'opal/browser/storage.rb', line 54

def autosave?
  @autosave
end

#clear ⇒ Object

Clear the storage.



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# File 'opal/browser/storage.rb', line 100

def clear
  @data.clear.tap {
    save if autosave?
  }
end

#commit(&block) ⇒ Object

Call the block between a [#reload] and [#save].



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# File 'opal/browser/storage.rb', line 118

def commit(&block)
  autosave  = @autosave
  @autosave = false
  result    = nil

  reload

  begin
    result = block.call
    save
  rescue
    reload
    raise
  ensure
    @autosave = autosave
  end

  result
end

#delete(key) ⇒ Object

Delete a value from the storage.



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# File 'opal/browser/storage.rb', line 93

def delete(key)
  @data.delete(key).tap {
    save if autosave?
  }
end

#each {|key, value| ... } ⇒ Object

Iterate over the (key, value) pairs in the storage.

Yields:

  • (key, value) 


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# File 'opal/browser/storage.rb', line 73

def each(&block)
  return enum_for :each unless block

  @data.each(&block)

  self
end

#no_autosave! ⇒ Object

Disable autosaving.



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# File 'opal/browser/storage.rb', line 64

def no_autosave!
  @autosave = false
end

#reload ⇒ Object

Load the storage.




# File 'opal/browser/storage.rb', line 142

#replace(new) ⇒ Object

Replace the current storage with the given one.

Parameters:



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# File 'opal/browser/storage.rb', line 109

def replace(new)
  if String === new
    @data.replace(JSON.parse(new))
  else
    @data.replace(new)
  end
end

#save ⇒ Object 



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# File 'opal/browser/storage.rb', line 153

def save
  `#@window.localStorage[#@name] = #{JSON.dump(self)}`
end

#to_h ⇒ Object 



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# File 'opal/browser/storage.rb', line 138

def to_h
  @data
end

#to_json ⇒ String

Convert the storage to JSON.

Returns:

  • (String) —

    the JSON representation



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# File 'opal/browser/storage.rb', line 199

def to_json
  io = StringIO.new << "{"

  io << JSON.create_id.to_json << ":" << self.class.name.to_json << ","

  @data.each {|key, value|
    io << key.to_json.to_s << ":" << value.to_json << ","
  }

  io.seek(-1, IO::SEEK_CUR)
  io << "}"

  io.string
end