Module: Tuile::Component::HasValue

Included in:
AbstractStringField, Checkbox, CheckboxGroup, ComboBox, IntegerField, RadioGroup
Defined in:
lib/tuile/component/has_value.rb,
sig/tuile.rbs

Overview

The value seam every input component shares: a settable/gettable #value of any type, an #on_value_change listener, #empty?, and #clear. A form (a future binder) drives a mix of field types uniformly through it, not caring that a TextField's value is a String while another field's is a domain object.

field.on_value_change = ->(v) { puts "now: #{v.inspect}" }
field.value = "hello"   # fires the listener
field.clear             # value = empty_value, fires again

The default #value=/#value keep the value in @value and are enough for a component with nothing more natural — you get a repaint and the listener for free. An includer whose value lives elsewhere overrides both (AbstractStringField backs them with its text buffer). Override #empty_value when the empty sentinel isn't nil (a text field's is "").

Implementation details

Deliberately smaller than Vaadin's HasValue: read-only, required-indicator, the from-client/old-value event payload, and converters all belong to the not-yet-built form layer, not here.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#on_value_change ⇒ Proc, ...

@return — one-arg callable fired with the new value whenever #value actually changes — never on a no-op set.

Returns:

  • (Proc, Method, nil) 


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# File 'lib/tuile/component/has_value.rb', line 28

def on_value_change
  @on_value_change
end

Instance Method Details

#clear ⇒ void

This method returns an undefined value.

Resets #value to #empty_value.



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# File 'lib/tuile/component/has_value.rb', line 49

def clear = (self.value = empty_value)

#empty? ⇒ Boolean

@return — true iff #value equals #empty_value.

Returns:

  • (Boolean) 


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# File 'lib/tuile/component/has_value.rb', line 45

def empty? = value == empty_value

#empty_value ⇒ Object

@return — the value #empty?/#clear treat as empty; nil unless an includer overrides it.

Returns:

  • (Object) 


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# File 'lib/tuile/component/has_value.rb', line 53

def empty_value = nil

#focusable? ⇒ Boolean

Input fields are focusable by default (overrides Tuile::Component#focusable?); a read-only display field could override back to false. Only focusable? lives here — tab_stop? diverges between leaf fields and composing wrappers, so it stays per-class (DECISIONS.md D-integer-field).

Returns:

  • (Boolean) 


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# File 'lib/tuile/component/has_value.rb', line 61

def focusable? = true

#value ⇒ Object

@return — the current value; nil until first set.

Returns:

  • (Object) 


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# File 'lib/tuile/component/has_value.rb', line 31

def value = @value

#value=(new_value) ⇒ void

This method returns an undefined value.

No-op (no repaint, no listener) when equal to the current value.

@param new_value

Parameters:

  • new_value (Object) 


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# File 'lib/tuile/component/has_value.rb', line 36

def value=(new_value)
  return if value == new_value

  @value = new_value
  invalidate
  on_value_change&.call(new_value)
end