Class: Proc

Inherits:
Object show all
Defined in:
lib/volt/reactive/computation.rb

Instance Method Summary collapse

Instance Method Details

#watch! ⇒ Object 



133
134
135
136
137
138
139
140
141
 
# File 'lib/volt/reactive/computation.rb', line 133

def watch!
  computation = Volt::Computation.new(self)

  # Initial run
  computation.compute!

  # return the computation
  computation
end

#watch_and_resolve! ⇒ Object

Does an watch and if the result is a promise, resolves the promise. #watch_and_resolve! takes a block that will be passed the resolved results of the proc.

Example:

-> { }



175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
 
# File 'lib/volt/reactive/computation.rb', line 175

def watch_and_resolve!
  unless block_given?
    raise "watch_and_resolve! requires a block to call when the value is resolved or another value other than a promise is returned in the watch."
  end

  computation = Proc.new do
    result = self.call

    if result.is_a?(Promise)
      result.then do |final|
        yield(final)
      end
    else
      yield(result)
    end
  end.watch!

  # Return the computation
  computation
end

#watch_until!(value, &block) ⇒ Volt::Computation

Watches a proc until the value returned equals the passed in value. When the value matches, the block is called.

Parameters:

  • the —

    value to match

Returns:



148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
 
# File 'lib/volt/reactive/computation.rb', line 148

def watch_until!(value, &block)
  computation = Proc.new do |comp|
    # First fetch the value
    result = self.call

    if result == value
      # Values match

      # call the block
      Volt::Computation.run_without_tracking do
        block.call
      end

      # stop the computation
      comp.stop
    end
  end.watch!

  computation
end