Class: Volt::Persistors::ArrayStore

Inherits:
Store show all
Includes:
StoreState
Defined in:
lib/volt/models/persistors/array_store.rb

Constant Summary collapse

@@query_pool = 
QueryListenerPool.new

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from StoreState

#change_state_to, #loaded, #state

Methods inherited from Store

#read_new_model, #saved?

Methods inherited from Base

#changed, #loaded

Constructor Details

#initialize(model, tasks = nil) ⇒ ArrayStore

Returns a new instance of ArrayStore.



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# File 'lib/volt/models/persistors/array_store.rb', line 18

def initialize(model, tasks = nil)
  super

  @query = @model.options[:query]
  @limit = @model.options[:limit]
  @skip = @model.options[:skip]

  @skip = nil if @skip == 0
end

Instance Attribute Details

#model ⇒ Object (readonly)

Returns the value of attribute model.



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# File 'lib/volt/models/persistors/array_store.rb', line 12

def model
  @model
end

Class Method Details

.query_pool ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 14

def self.query_pool
  @@query_pool
end

Instance Method Details

#add(index, data) ⇒ Object

Called from backend



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# File 'lib/volt/models/persistors/array_store.rb', line 158

def add(index, data)
  $loading_models = true

  data_id = data['_id'] || data[:_id]

  # Don't add if the model is already in the ArrayModel
  unless @model.array.find { |v| v._id == data_id }
    # Find the existing model, or create one
    new_model = @@identity_map.find(data_id) do
      new_options = @model.options.merge(path: @model.path + [:[]], parent: @model)
      @model.new_model(data, new_options, :loaded)
    end

    @model.insert(index, new_model)
  end

  $loading_models = false
end

#added(model, index) ⇒ Object

When a model is added to this collection, we call its “changed” method. This should trigger a save.



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# File 'lib/volt/models/persistors/array_store.rb', line 198

def added(model, index)
  if model.persistor
    # Tell the persistor it was added
    model.persistor.add_to_collection
  end
end

#channel_name ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 192

def channel_name
  @model.path[-1]
end

#event_added(event, first, first_for_event) ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 28

def event_added(event, first, first_for_event)
  # First event, we load the data.
  if first
    @has_events = true
    load_data
  end
end

#event_removed(event, last, last_for_event) ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 36

def event_removed(event, last, last_for_event)
  # Remove listener where there are no more events on this model
  if last
    @has_events = false
    stop_listening
  end
end

#find(query = nil, &block) ⇒ Object

Find can take either a query object, or a block that returns a query object. Use the block style if you need reactive updating queries



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# File 'lib/volt/models/persistors/array_store.rb', line 116

def find(query = nil, &block)
  # Set a default query if there is no block
  if block
    if query
      fail 'Query should not be passed in to a find if a block is specified'
    end
    query = block
  else
    query ||= {}
  end

  return Cursor.new([], @model.options.merge(query: query))
end

#limit(limit) ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 130

def limit(limit)
  return Cursor.new([], @model.options.merge(limit: limit))
end

#load_data ⇒ Object

Called the first time data is requested from this collection



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# File 'lib/volt/models/persistors/array_store.rb', line 61

def load_data
  # Don't load data from any queried
  if @state == :not_loaded || @state == :dirty
    # puts "Load Data at #{@model.path.inspect} - query: #{@query.inspect} on #{self.inspect}"
    change_state_to :loading

    if @query.is_a?(Proc)
      @query_computation = -> do
        stop_listening(false)

        change_state_to :loading

        new_query = @query.call

        run_query(@model, @query.call, @skip, @limit)
      end.watch!
    else
      run_query(@model, @query, @skip, @limit)
    end
  end
end

#remove(ids) ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 177

def remove(ids)
  $loading_models = true
  ids.each do |id|
    # TODO: optimize this delete so we don't need to loop
    @model.each_with_index do |model, index|
      if model._id == id
        del = @model.delete_at(index)
        break
      end
    end
  end

  $loading_models = false
end

#removed(model) ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 205

def removed(model)
  if model.persistor
    # Tell the persistor it was removed
    model.persistor.remove_from_collection
  end

  if defined?($loading_models) && $loading_models
    return
  else
    StoreTasks.delete(channel_name, model.attributes[:_id])
  end
end

#run_query(model, query = {}, skip = nil, limit = nil) ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 89

def run_query(model, query={}, skip=nil, limit=nil)
  @model.clear

  collection = model.path.last
  # Scope to the parent
  if model.path.size > 1
    parent = model.parent

    parent.persistor.ensure_setup if parent.persistor

    if parent && (attrs = parent.attributes) && attrs[:_id].true?
      query[:"#{model.path[-3].singularize}_id"] = attrs[:_id]
    end
  end

  # The full query contains the skip and limit
  full_query = [query, skip, limit]
  @query_listener = @@query_pool.lookup(collection, full_query) do
    # Create if it does not exist
    QueryListener.new(@@query_pool, @tasks, collection, full_query)
  end

  @query_listener.add_store(self)
end

#skip(skip) ⇒ Object 



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# File 'lib/volt/models/persistors/array_store.rb', line 134

def skip(skip)
  return Cursor.new([], @model.options.merge(skip: skip))
end

#stop_listening(stop_watching_query = true) ⇒ Object

Called when an event is removed and we no longer want to keep in sync with the database.



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# File 'lib/volt/models/persistors/array_store.rb', line 46

def stop_listening(stop_watching_query = true)
  return if @has_events
  return if @fetch_promises && @fetch_promises.size > 0

  @query_computation.stop if @query_computation && stop_watching_query

  if @query_listener
    @query_listener.remove_store(self)
    @query_listener = nil
  end

  @state = :dirty
end

#then(&block) ⇒ Object

Returns a promise that is resolved/rejected when the query is complete. Any passed block will be passed to the promises then. Then will be passed the model.



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# File 'lib/volt/models/persistors/array_store.rb', line 140

def then(&block)
  promise = Promise.new

  promise = promise.then(&block) if block

  if @state == :loaded
    promise.resolve(@model)
  else
    @fetch_promises ||= []
    @fetch_promises << promise

    load_data
  end

  promise
end

#unload_data ⇒ Object

Clear out the models data, since we’re not listening anymore.



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# File 'lib/volt/models/persistors/array_store.rb', line 84

def unload_data
  change_state_to :not_loaded
  @model.clear
end