Class: OpenHAB::Core::Things::Channel

Inherits:
Object
  • Object
show all
Defined in:
lib/openhab/core/things/channel.rb

Overview

Channel is a part of a Thing that represents a functionality of it. Therefore Items can be linked a to a channel.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#channel_type ⇒ ChannelType (readonly)

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 51

def channel_type
  ChannelType.registry.get_channel_type(channel_type_uid)
end

#channel_type_uid ⇒ ChannelTypeUID (readonly)

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 29

class Channel
  extend Forwardable

  delegate %i[item items thing] => :uid

  # @return [String]
  def inspect
    r = "#<OpenHAB::Core::Things::Channel #{uid}"
    r += " #{label.inspect}" if label
    r += " description=#{description.inspect}" if description
    r += " kind=#{kind.inspect}"
    r += " channel_type_uid=#{channel_type_uid.inspect}" if channel_type_uid
    r += " configuration=#{configuration.properties.to_h}" unless configuration.properties.empty?
    r += " properties=#{properties.to_h}" unless properties.empty?
    r += " default_tags=#{default_tags.to_a}" unless default_tags.empty?
    r += " auto_update_policy=#{auto_update_policy}" if auto_update_policy
    r += " accepted_item_type=#{accepted_item_type}" if accepted_item_type
    "#{r}>"
  end

  # @!attribute [r] channel_type
  # @return [ChannelType]
  def channel_type
    ChannelType.registry.get_channel_type(channel_type_uid)
  end

  # @return [String]
  def to_s
    uid.to_s
  end

  # @!attribute item_name [r]
  # Return the name of the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [String, nil]
  def item_name
    item_names.first
  end

  # @!attribute item_names [r]
  # Return the names of all of the items this channel is linked to.
  #
  # @return [Array<String>]
  def item_names
    Things::Links::Provider.registry.get_linked_item_names(uid)
  end

  # @!attribute item [r]
  # Return the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [Items::Item, nil]
  def item
    items.first
  end

  # @!attribute items [r]
  # Return all of the items this channel is linked to.
  #
  # @return [Array<Items::Item>]
  def items
    Things::Links::Provider.registry.get_linked_items(uid).map { |item| Items::Proxy.new(item) }
  end

  #
  # @!attribute links [r]
  # Returns all of the channel's links (items and link configurations).
  #
  # @return [Items::ItemChannelLinks] An array of ItemChannelLink or an empty array
  #
  # @example Get the configuration of the first link
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.first.configuration
  #
  # @example Remove all managed links
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.clear
  #
  # @see link
  # @see unlink
  #
  def links
    Items::ItemChannelLinks.new(uid, Things::Links::Provider.registry.get_links(uid))
  end

  #
  # @return [ItemChannelLink, nil]
  #
  # @overload link
  #   Returns the channel's link. If an channel is linked to more than one item,
  #   this method only returns the first link.
  #
  #   @return [Things::ItemChannelLink, nil]
  #
  # @overload link(item, config = {})
  #
  #   Links the channel to an item.
  #
  #   @param [String, Items::Item] item The item to link to.
  #   @param [Hash] config The configuration for the link.
  #
  #   @return [Things::ItemChannelLink] The created link.
  #
  #   @example Link a channel to an item
  #     things["mqtt:topic:livingroom-light"].channels["power"].link(LivingRoom_Light_Power)
  #
  #   @example Specify a link configuration
  #     things["mqtt:topic:outdoor-thermometer"].channels["temperature"].link(
  #       High_Temperature_Alert,
  #       profile: "system:hysteresis",
  #       lower: "29 °C",
  #       upper: "30 °C")
  #
  #   @see links
  #   @see unlink
  #
  def link(item = nil, config = nil)
    return Things::Links::Provider.registry.get_links(uid).first if item.nil? && config.nil?

    config ||= {}
    Core::Things::Links::Provider.create_link(item, self, config).tap do |new_link|
      provider = Core::Things::Links::Provider.current
      if !(current_link = provider.get(new_link.uid))
        provider.add(new_link)
      elsif current_link.configuration != config
        provider.update(new_link)
      end
    end
  end

  #
  # Removes a link to an item from managed link providers.
  #
  # @param [String, Items::Item] item The item to remove the link to.
  #
  # @return [Things::ItemChannelLink, nil] The removed link, if found.
  # @raise [FrozenError] if the link is not managed by a managed link provider.
  #
  # @see link
  # @see links
  #
  def unlink(item)
    link_to_delete = Things::Links::Provider.create_link(item, self, {})
    provider = Things::Links::Provider.registry.provider_for(link_to_delete.uid)
    unless provider.is_a?(ManagedProvider)
      raise FrozenError,
            "Cannot remove the link #{link_to_delete.uid} from non-managed provider #{provider.inspect}"
    end

    provider.remove(link_to_delete.uid)
  end

  # @deprecated OH3.4 this whole section is not needed in OH4+. Also see Thing#config_eql?
  if Core.version < Core::V4_0
    # @!visibility private
    module ChannelComparable
      # @!visibility private
      # This is only needed in OH3 because it is implemented in OH4 core
      def ==(other)
        return true if equal?(other)
        return false unless other.is_a?(Channel)

        %i[class
           uid
           label
           description
           kind
           channel_type_uid
           configuration
           properties
           default_tags
           auto_update_policy
           accepted_item_type].all? do |attr|
          send(attr) == other.send(attr)
        end
      end
    end
    org.openhab.core.thing.binding.builder.ChannelBuilder.const_get(:ChannelImpl).prepend(ChannelComparable)
  end
end

#item ⇒ Items::Item? (readonly)

Return the item this channel is linked to. If a channel is linked to more than one item, this method only returns the first item.

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 29

class Channel
  extend Forwardable

  delegate %i[item items thing] => :uid

  # @return [String]
  def inspect
    r = "#<OpenHAB::Core::Things::Channel #{uid}"
    r += " #{label.inspect}" if label
    r += " description=#{description.inspect}" if description
    r += " kind=#{kind.inspect}"
    r += " channel_type_uid=#{channel_type_uid.inspect}" if channel_type_uid
    r += " configuration=#{configuration.properties.to_h}" unless configuration.properties.empty?
    r += " properties=#{properties.to_h}" unless properties.empty?
    r += " default_tags=#{default_tags.to_a}" unless default_tags.empty?
    r += " auto_update_policy=#{auto_update_policy}" if auto_update_policy
    r += " accepted_item_type=#{accepted_item_type}" if accepted_item_type
    "#{r}>"
  end

  # @!attribute [r] channel_type
  # @return [ChannelType]
  def channel_type
    ChannelType.registry.get_channel_type(channel_type_uid)
  end

  # @return [String]
  def to_s
    uid.to_s
  end

  # @!attribute item_name [r]
  # Return the name of the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [String, nil]
  def item_name
    item_names.first
  end

  # @!attribute item_names [r]
  # Return the names of all of the items this channel is linked to.
  #
  # @return [Array<String>]
  def item_names
    Things::Links::Provider.registry.get_linked_item_names(uid)
  end

  # @!attribute item [r]
  # Return the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [Items::Item, nil]
  def item
    items.first
  end

  # @!attribute items [r]
  # Return all of the items this channel is linked to.
  #
  # @return [Array<Items::Item>]
  def items
    Things::Links::Provider.registry.get_linked_items(uid).map { |item| Items::Proxy.new(item) }
  end

  #
  # @!attribute links [r]
  # Returns all of the channel's links (items and link configurations).
  #
  # @return [Items::ItemChannelLinks] An array of ItemChannelLink or an empty array
  #
  # @example Get the configuration of the first link
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.first.configuration
  #
  # @example Remove all managed links
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.clear
  #
  # @see link
  # @see unlink
  #
  def links
    Items::ItemChannelLinks.new(uid, Things::Links::Provider.registry.get_links(uid))
  end

  #
  # @return [ItemChannelLink, nil]
  #
  # @overload link
  #   Returns the channel's link. If an channel is linked to more than one item,
  #   this method only returns the first link.
  #
  #   @return [Things::ItemChannelLink, nil]
  #
  # @overload link(item, config = {})
  #
  #   Links the channel to an item.
  #
  #   @param [String, Items::Item] item The item to link to.
  #   @param [Hash] config The configuration for the link.
  #
  #   @return [Things::ItemChannelLink] The created link.
  #
  #   @example Link a channel to an item
  #     things["mqtt:topic:livingroom-light"].channels["power"].link(LivingRoom_Light_Power)
  #
  #   @example Specify a link configuration
  #     things["mqtt:topic:outdoor-thermometer"].channels["temperature"].link(
  #       High_Temperature_Alert,
  #       profile: "system:hysteresis",
  #       lower: "29 °C",
  #       upper: "30 °C")
  #
  #   @see links
  #   @see unlink
  #
  def link(item = nil, config = nil)
    return Things::Links::Provider.registry.get_links(uid).first if item.nil? && config.nil?

    config ||= {}
    Core::Things::Links::Provider.create_link(item, self, config).tap do |new_link|
      provider = Core::Things::Links::Provider.current
      if !(current_link = provider.get(new_link.uid))
        provider.add(new_link)
      elsif current_link.configuration != config
        provider.update(new_link)
      end
    end
  end

  #
  # Removes a link to an item from managed link providers.
  #
  # @param [String, Items::Item] item The item to remove the link to.
  #
  # @return [Things::ItemChannelLink, nil] The removed link, if found.
  # @raise [FrozenError] if the link is not managed by a managed link provider.
  #
  # @see link
  # @see links
  #
  def unlink(item)
    link_to_delete = Things::Links::Provider.create_link(item, self, {})
    provider = Things::Links::Provider.registry.provider_for(link_to_delete.uid)
    unless provider.is_a?(ManagedProvider)
      raise FrozenError,
            "Cannot remove the link #{link_to_delete.uid} from non-managed provider #{provider.inspect}"
    end

    provider.remove(link_to_delete.uid)
  end

  # @deprecated OH3.4 this whole section is not needed in OH4+. Also see Thing#config_eql?
  if Core.version < Core::V4_0
    # @!visibility private
    module ChannelComparable
      # @!visibility private
      # This is only needed in OH3 because it is implemented in OH4 core
      def ==(other)
        return true if equal?(other)
        return false unless other.is_a?(Channel)

        %i[class
           uid
           label
           description
           kind
           channel_type_uid
           configuration
           properties
           default_tags
           auto_update_policy
           accepted_item_type].all? do |attr|
          send(attr) == other.send(attr)
        end
      end
    end
    org.openhab.core.thing.binding.builder.ChannelBuilder.const_get(:ChannelImpl).prepend(ChannelComparable)
  end
end

#item_name ⇒ String? (readonly)

Return the name of the item this channel is linked to. If a channel is linked to more than one item, this method only returns the first item.

Returns:

  • (String, nil) 


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# File 'lib/openhab/core/things/channel.rb', line 65

def item_name
  item_names.first
end

#item_names ⇒ Array<String> (readonly)

Return the names of all of the items this channel is linked to.

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 73

def item_names
  Things::Links::Provider.registry.get_linked_item_names(uid)
end

#items ⇒ Array<Items::Item> (readonly)

Return all of the items this channel is linked to.

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 29

class Channel
  extend Forwardable

  delegate %i[item items thing] => :uid

  # @return [String]
  def inspect
    r = "#<OpenHAB::Core::Things::Channel #{uid}"
    r += " #{label.inspect}" if label
    r += " description=#{description.inspect}" if description
    r += " kind=#{kind.inspect}"
    r += " channel_type_uid=#{channel_type_uid.inspect}" if channel_type_uid
    r += " configuration=#{configuration.properties.to_h}" unless configuration.properties.empty?
    r += " properties=#{properties.to_h}" unless properties.empty?
    r += " default_tags=#{default_tags.to_a}" unless default_tags.empty?
    r += " auto_update_policy=#{auto_update_policy}" if auto_update_policy
    r += " accepted_item_type=#{accepted_item_type}" if accepted_item_type
    "#{r}>"
  end

  # @!attribute [r] channel_type
  # @return [ChannelType]
  def channel_type
    ChannelType.registry.get_channel_type(channel_type_uid)
  end

  # @return [String]
  def to_s
    uid.to_s
  end

  # @!attribute item_name [r]
  # Return the name of the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [String, nil]
  def item_name
    item_names.first
  end

  # @!attribute item_names [r]
  # Return the names of all of the items this channel is linked to.
  #
  # @return [Array<String>]
  def item_names
    Things::Links::Provider.registry.get_linked_item_names(uid)
  end

  # @!attribute item [r]
  # Return the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [Items::Item, nil]
  def item
    items.first
  end

  # @!attribute items [r]
  # Return all of the items this channel is linked to.
  #
  # @return [Array<Items::Item>]
  def items
    Things::Links::Provider.registry.get_linked_items(uid).map { |item| Items::Proxy.new(item) }
  end

  #
  # @!attribute links [r]
  # Returns all of the channel's links (items and link configurations).
  #
  # @return [Items::ItemChannelLinks] An array of ItemChannelLink or an empty array
  #
  # @example Get the configuration of the first link
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.first.configuration
  #
  # @example Remove all managed links
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.clear
  #
  # @see link
  # @see unlink
  #
  def links
    Items::ItemChannelLinks.new(uid, Things::Links::Provider.registry.get_links(uid))
  end

  #
  # @return [ItemChannelLink, nil]
  #
  # @overload link
  #   Returns the channel's link. If an channel is linked to more than one item,
  #   this method only returns the first link.
  #
  #   @return [Things::ItemChannelLink, nil]
  #
  # @overload link(item, config = {})
  #
  #   Links the channel to an item.
  #
  #   @param [String, Items::Item] item The item to link to.
  #   @param [Hash] config The configuration for the link.
  #
  #   @return [Things::ItemChannelLink] The created link.
  #
  #   @example Link a channel to an item
  #     things["mqtt:topic:livingroom-light"].channels["power"].link(LivingRoom_Light_Power)
  #
  #   @example Specify a link configuration
  #     things["mqtt:topic:outdoor-thermometer"].channels["temperature"].link(
  #       High_Temperature_Alert,
  #       profile: "system:hysteresis",
  #       lower: "29 °C",
  #       upper: "30 °C")
  #
  #   @see links
  #   @see unlink
  #
  def link(item = nil, config = nil)
    return Things::Links::Provider.registry.get_links(uid).first if item.nil? && config.nil?

    config ||= {}
    Core::Things::Links::Provider.create_link(item, self, config).tap do |new_link|
      provider = Core::Things::Links::Provider.current
      if !(current_link = provider.get(new_link.uid))
        provider.add(new_link)
      elsif current_link.configuration != config
        provider.update(new_link)
      end
    end
  end

  #
  # Removes a link to an item from managed link providers.
  #
  # @param [String, Items::Item] item The item to remove the link to.
  #
  # @return [Things::ItemChannelLink, nil] The removed link, if found.
  # @raise [FrozenError] if the link is not managed by a managed link provider.
  #
  # @see link
  # @see links
  #
  def unlink(item)
    link_to_delete = Things::Links::Provider.create_link(item, self, {})
    provider = Things::Links::Provider.registry.provider_for(link_to_delete.uid)
    unless provider.is_a?(ManagedProvider)
      raise FrozenError,
            "Cannot remove the link #{link_to_delete.uid} from non-managed provider #{provider.inspect}"
    end

    provider.remove(link_to_delete.uid)
  end

  # @deprecated OH3.4 this whole section is not needed in OH4+. Also see Thing#config_eql?
  if Core.version < Core::V4_0
    # @!visibility private
    module ChannelComparable
      # @!visibility private
      # This is only needed in OH3 because it is implemented in OH4 core
      def ==(other)
        return true if equal?(other)
        return false unless other.is_a?(Channel)

        %i[class
           uid
           label
           description
           kind
           channel_type_uid
           configuration
           properties
           default_tags
           auto_update_policy
           accepted_item_type].all? do |attr|
          send(attr) == other.send(attr)
        end
      end
    end
    org.openhab.core.thing.binding.builder.ChannelBuilder.const_get(:ChannelImpl).prepend(ChannelComparable)
  end
end

#links ⇒ Items::ItemChannelLinks (readonly)

Returns all of the channel’s links (items and link configurations).

Examples:

Get the configuration of the first link

things["mqtt:topic:livingroom-light"].channel["power"].links.first.configuration

Remove all managed links

things["mqtt:topic:livingroom-light"].channel["power"].links.clear

Returns:

See Also:



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# File 'lib/openhab/core/things/channel.rb', line 109

def links
  Items::ItemChannelLinks.new(uid, Things::Links::Provider.registry.get_links(uid))
end

#thing ⇒ Thing? (readonly)

Return the thing this channel is associated with.

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 29

class Channel
  extend Forwardable

  delegate %i[item items thing] => :uid

  # @return [String]
  def inspect
    r = "#<OpenHAB::Core::Things::Channel #{uid}"
    r += " #{label.inspect}" if label
    r += " description=#{description.inspect}" if description
    r += " kind=#{kind.inspect}"
    r += " channel_type_uid=#{channel_type_uid.inspect}" if channel_type_uid
    r += " configuration=#{configuration.properties.to_h}" unless configuration.properties.empty?
    r += " properties=#{properties.to_h}" unless properties.empty?
    r += " default_tags=#{default_tags.to_a}" unless default_tags.empty?
    r += " auto_update_policy=#{auto_update_policy}" if auto_update_policy
    r += " accepted_item_type=#{accepted_item_type}" if accepted_item_type
    "#{r}>"
  end

  # @!attribute [r] channel_type
  # @return [ChannelType]
  def channel_type
    ChannelType.registry.get_channel_type(channel_type_uid)
  end

  # @return [String]
  def to_s
    uid.to_s
  end

  # @!attribute item_name [r]
  # Return the name of the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [String, nil]
  def item_name
    item_names.first
  end

  # @!attribute item_names [r]
  # Return the names of all of the items this channel is linked to.
  #
  # @return [Array<String>]
  def item_names
    Things::Links::Provider.registry.get_linked_item_names(uid)
  end

  # @!attribute item [r]
  # Return the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [Items::Item, nil]
  def item
    items.first
  end

  # @!attribute items [r]
  # Return all of the items this channel is linked to.
  #
  # @return [Array<Items::Item>]
  def items
    Things::Links::Provider.registry.get_linked_items(uid).map { |item| Items::Proxy.new(item) }
  end

  #
  # @!attribute links [r]
  # Returns all of the channel's links (items and link configurations).
  #
  # @return [Items::ItemChannelLinks] An array of ItemChannelLink or an empty array
  #
  # @example Get the configuration of the first link
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.first.configuration
  #
  # @example Remove all managed links
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.clear
  #
  # @see link
  # @see unlink
  #
  def links
    Items::ItemChannelLinks.new(uid, Things::Links::Provider.registry.get_links(uid))
  end

  #
  # @return [ItemChannelLink, nil]
  #
  # @overload link
  #   Returns the channel's link. If an channel is linked to more than one item,
  #   this method only returns the first link.
  #
  #   @return [Things::ItemChannelLink, nil]
  #
  # @overload link(item, config = {})
  #
  #   Links the channel to an item.
  #
  #   @param [String, Items::Item] item The item to link to.
  #   @param [Hash] config The configuration for the link.
  #
  #   @return [Things::ItemChannelLink] The created link.
  #
  #   @example Link a channel to an item
  #     things["mqtt:topic:livingroom-light"].channels["power"].link(LivingRoom_Light_Power)
  #
  #   @example Specify a link configuration
  #     things["mqtt:topic:outdoor-thermometer"].channels["temperature"].link(
  #       High_Temperature_Alert,
  #       profile: "system:hysteresis",
  #       lower: "29 °C",
  #       upper: "30 °C")
  #
  #   @see links
  #   @see unlink
  #
  def link(item = nil, config = nil)
    return Things::Links::Provider.registry.get_links(uid).first if item.nil? && config.nil?

    config ||= {}
    Core::Things::Links::Provider.create_link(item, self, config).tap do |new_link|
      provider = Core::Things::Links::Provider.current
      if !(current_link = provider.get(new_link.uid))
        provider.add(new_link)
      elsif current_link.configuration != config
        provider.update(new_link)
      end
    end
  end

  #
  # Removes a link to an item from managed link providers.
  #
  # @param [String, Items::Item] item The item to remove the link to.
  #
  # @return [Things::ItemChannelLink, nil] The removed link, if found.
  # @raise [FrozenError] if the link is not managed by a managed link provider.
  #
  # @see link
  # @see links
  #
  def unlink(item)
    link_to_delete = Things::Links::Provider.create_link(item, self, {})
    provider = Things::Links::Provider.registry.provider_for(link_to_delete.uid)
    unless provider.is_a?(ManagedProvider)
      raise FrozenError,
            "Cannot remove the link #{link_to_delete.uid} from non-managed provider #{provider.inspect}"
    end

    provider.remove(link_to_delete.uid)
  end

  # @deprecated OH3.4 this whole section is not needed in OH4+. Also see Thing#config_eql?
  if Core.version < Core::V4_0
    # @!visibility private
    module ChannelComparable
      # @!visibility private
      # This is only needed in OH3 because it is implemented in OH4 core
      def ==(other)
        return true if equal?(other)
        return false unless other.is_a?(Channel)

        %i[class
           uid
           label
           description
           kind
           channel_type_uid
           configuration
           properties
           default_tags
           auto_update_policy
           accepted_item_type].all? do |attr|
          send(attr) == other.send(attr)
        end
      end
    end
    org.openhab.core.thing.binding.builder.ChannelBuilder.const_get(:ChannelImpl).prepend(ChannelComparable)
  end
end

#uid ⇒ ChannelUID (readonly)

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 29

class Channel
  extend Forwardable

  delegate %i[item items thing] => :uid

  # @return [String]
  def inspect
    r = "#<OpenHAB::Core::Things::Channel #{uid}"
    r += " #{label.inspect}" if label
    r += " description=#{description.inspect}" if description
    r += " kind=#{kind.inspect}"
    r += " channel_type_uid=#{channel_type_uid.inspect}" if channel_type_uid
    r += " configuration=#{configuration.properties.to_h}" unless configuration.properties.empty?
    r += " properties=#{properties.to_h}" unless properties.empty?
    r += " default_tags=#{default_tags.to_a}" unless default_tags.empty?
    r += " auto_update_policy=#{auto_update_policy}" if auto_update_policy
    r += " accepted_item_type=#{accepted_item_type}" if accepted_item_type
    "#{r}>"
  end

  # @!attribute [r] channel_type
  # @return [ChannelType]
  def channel_type
    ChannelType.registry.get_channel_type(channel_type_uid)
  end

  # @return [String]
  def to_s
    uid.to_s
  end

  # @!attribute item_name [r]
  # Return the name of the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [String, nil]
  def item_name
    item_names.first
  end

  # @!attribute item_names [r]
  # Return the names of all of the items this channel is linked to.
  #
  # @return [Array<String>]
  def item_names
    Things::Links::Provider.registry.get_linked_item_names(uid)
  end

  # @!attribute item [r]
  # Return the item this channel is linked to. If a channel is linked to more than one item,
  # this method only returns the first item.
  #
  # @return [Items::Item, nil]
  def item
    items.first
  end

  # @!attribute items [r]
  # Return all of the items this channel is linked to.
  #
  # @return [Array<Items::Item>]
  def items
    Things::Links::Provider.registry.get_linked_items(uid).map { |item| Items::Proxy.new(item) }
  end

  #
  # @!attribute links [r]
  # Returns all of the channel's links (items and link configurations).
  #
  # @return [Items::ItemChannelLinks] An array of ItemChannelLink or an empty array
  #
  # @example Get the configuration of the first link
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.first.configuration
  #
  # @example Remove all managed links
  #   things["mqtt:topic:livingroom-light"].channel["power"].links.clear
  #
  # @see link
  # @see unlink
  #
  def links
    Items::ItemChannelLinks.new(uid, Things::Links::Provider.registry.get_links(uid))
  end

  #
  # @return [ItemChannelLink, nil]
  #
  # @overload link
  #   Returns the channel's link. If an channel is linked to more than one item,
  #   this method only returns the first link.
  #
  #   @return [Things::ItemChannelLink, nil]
  #
  # @overload link(item, config = {})
  #
  #   Links the channel to an item.
  #
  #   @param [String, Items::Item] item The item to link to.
  #   @param [Hash] config The configuration for the link.
  #
  #   @return [Things::ItemChannelLink] The created link.
  #
  #   @example Link a channel to an item
  #     things["mqtt:topic:livingroom-light"].channels["power"].link(LivingRoom_Light_Power)
  #
  #   @example Specify a link configuration
  #     things["mqtt:topic:outdoor-thermometer"].channels["temperature"].link(
  #       High_Temperature_Alert,
  #       profile: "system:hysteresis",
  #       lower: "29 °C",
  #       upper: "30 °C")
  #
  #   @see links
  #   @see unlink
  #
  def link(item = nil, config = nil)
    return Things::Links::Provider.registry.get_links(uid).first if item.nil? && config.nil?

    config ||= {}
    Core::Things::Links::Provider.create_link(item, self, config).tap do |new_link|
      provider = Core::Things::Links::Provider.current
      if !(current_link = provider.get(new_link.uid))
        provider.add(new_link)
      elsif current_link.configuration != config
        provider.update(new_link)
      end
    end
  end

  #
  # Removes a link to an item from managed link providers.
  #
  # @param [String, Items::Item] item The item to remove the link to.
  #
  # @return [Things::ItemChannelLink, nil] The removed link, if found.
  # @raise [FrozenError] if the link is not managed by a managed link provider.
  #
  # @see link
  # @see links
  #
  def unlink(item)
    link_to_delete = Things::Links::Provider.create_link(item, self, {})
    provider = Things::Links::Provider.registry.provider_for(link_to_delete.uid)
    unless provider.is_a?(ManagedProvider)
      raise FrozenError,
            "Cannot remove the link #{link_to_delete.uid} from non-managed provider #{provider.inspect}"
    end

    provider.remove(link_to_delete.uid)
  end

  # @deprecated OH3.4 this whole section is not needed in OH4+. Also see Thing#config_eql?
  if Core.version < Core::V4_0
    # @!visibility private
    module ChannelComparable
      # @!visibility private
      # This is only needed in OH3 because it is implemented in OH4 core
      def ==(other)
        return true if equal?(other)
        return false unless other.is_a?(Channel)

        %i[class
           uid
           label
           description
           kind
           channel_type_uid
           configuration
           properties
           default_tags
           auto_update_policy
           accepted_item_type].all? do |attr|
          send(attr) == other.send(attr)
        end
      end
    end
    org.openhab.core.thing.binding.builder.ChannelBuilder.const_get(:ChannelImpl).prepend(ChannelComparable)
  end
end

Instance Method Details

#inspect ⇒ String

Returns:

  • (String) 


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# File 'lib/openhab/core/things/channel.rb', line 35

def inspect
  r = "#<OpenHAB::Core::Things::Channel #{uid}"
  r += " #{label.inspect}" if label
  r += " description=#{description.inspect}" if description
  r += " kind=#{kind.inspect}"
  r += " channel_type_uid=#{channel_type_uid.inspect}" if channel_type_uid
  r += " configuration=#{configuration.properties.to_h}" unless configuration.properties.empty?
  r += " properties=#{properties.to_h}" unless properties.empty?
  r += " default_tags=#{default_tags.to_a}" unless default_tags.empty?
  r += " auto_update_policy=#{auto_update_policy}" if auto_update_policy
  r += " accepted_item_type=#{accepted_item_type}" if accepted_item_type
  "#{r}>"
end

#link ⇒ Things::ItemChannelLink? #link(item, config = {}) ⇒ Things::ItemChannelLink

Overloads:

  • #link ⇒ Things::ItemChannelLink?

    Returns the channel’s link. If an channel is linked to more than one item, this method only returns the first link.

    Returns:

  • #link(item, config = {}) ⇒ Things::ItemChannelLink

    Links the channel to an item.

    Examples:

    Link a channel to an item

    things["mqtt:topic:livingroom-light"].channels["power"].link(LivingRoom_Light_Power)

    Specify a link configuration

    things["mqtt:topic:outdoor-thermometer"].channels["temperature"].link(
  High_Temperature_Alert,
  profile: "system:hysteresis",
  lower: "29 °C",
  upper: "30 °C")

    Parameters:

    • item (String, Items::Item) —

      The item to link to.

    • config (Hash) (defaults to: {}) —

      The configuration for the link.

    Returns:

    See Also:

Returns:



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# File 'lib/openhab/core/things/channel.rb', line 144

def link(item = nil, config = nil)
  return Things::Links::Provider.registry.get_links(uid).first if item.nil? && config.nil?

  config ||= {}
  Core::Things::Links::Provider.create_link(item, self, config).tap do |new_link|
    provider = Core::Things::Links::Provider.current
    if !(current_link = provider.get(new_link.uid))
      provider.add(new_link)
    elsif current_link.configuration != config
      provider.update(new_link)
    end
  end
end

#to_s ⇒ String

Returns:

  • (String) 


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# File 'lib/openhab/core/things/channel.rb', line 56

def to_s
  uid.to_s
end

#unlink(item) ⇒ Things::ItemChannelLink?

Removes a link to an item from managed link providers.

Parameters:

  • item (String, Items::Item) —

    The item to remove the link to.

Returns:

Raises:

  • (FrozenError) —

    if the link is not managed by a managed link provider.

See Also:



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# File 'lib/openhab/core/things/channel.rb', line 169

def unlink(item)
  link_to_delete = Things::Links::Provider.create_link(item, self, {})
  provider = Things::Links::Provider.registry.provider_for(link_to_delete.uid)
  unless provider.is_a?(ManagedProvider)
    raise FrozenError,
          "Cannot remove the link #{link_to_delete.uid} from non-managed provider #{provider.inspect}"
  end

  provider.remove(link_to_delete.uid)
end