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.



18
19
20
21
22
 
# File 'lib/volt/models/persistors/array_store.rb', line 18

def initialize(model, tasks=nil)
  super

  @query = @model.options[:query]
end

Instance Attribute Details

#model ⇒ Object (readonly)

Returns the value of attribute model.



12
13
14
 
# File 'lib/volt/models/persistors/array_store.rb', line 12

def model
  @model
end

Class Method Details

.query_pool ⇒ Object 



14
15
16
 
# 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



144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
 
# File 'lib/volt/models/persistors/array_store.rb', line 144

def add(index, data)
  $loading_models = true

  data_id = data[:_id]

  # Don't add if the model is already in the ArrayModel
  if !@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.



184
185
186
187
188
189
 
# File 'lib/volt/models/persistors/array_store.rb', line 184

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

#channel_name ⇒ Object 



178
179
180
 
# File 'lib/volt/models/persistors/array_store.rb', line 178

def channel_name
  @model.path[-1]
end

#event_added(event, first, first_for_event) ⇒ Object 



24
25
26
27
28
29
30
 
# File 'lib/volt/models/persistors/array_store.rb', line 24

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 



32
33
34
35
36
37
38
 
# File 'lib/volt/models/persistors/array_store.rb', line 32

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



110
111
112
113
114
115
116
117
118
119
120
121
122
 
# File 'lib/volt/models/persistors/array_store.rb', line 110

def find(query=nil, &block)
  # Set a default query if there is no block
  if block
    if query
      raise "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

#load_data ⇒ Object

Called the first time data is requested from this collection



57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/volt/models/persistors/array_store.rb', line 57

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

#remove(ids) ⇒ Object 



163
164
165
166
167
168
169
170
171
172
173
174
175
176
 
# File 'lib/volt/models/persistors/array_store.rb', line 163

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 



191
192
193
194
195
196
197
198
199
200
201
202
 
# File 'lib/volt/models/persistors/array_store.rb', line 191

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 = {}) ⇒ Object 



85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
 
# File 'lib/volt/models/persistors/array_store.rb', line 85

def run_query(model, query={})
  @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

  @query_listener = @@query_pool.lookup(collection, query) do
    # Create if it does not exist
    QueryListener.new(@@query_pool, @tasks, collection, query)
  end

  @query_listener.add_store(self)
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.



42
43
44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/volt/models/persistors/array_store.rb', line 42

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.



126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
 
# File 'lib/volt/models/persistors/array_store.rb', line 126

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

  return promise
end

#unload_data ⇒ Object

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



80
81
82
83
 
# File 'lib/volt/models/persistors/array_store.rb', line 80

def unload_data
  change_state_to :not_loaded
  @model.clear
end