BACnet.Protocol.ObjectTypes.Calendar (bacstack v0.1.0-dev.1)

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The Calendar object maintains a list of calendar dates and/or date patterns that represent holidays, special events, or other date-based exceptions. Other objects (primarily Schedule objects) reference a Calendar by its Object Identifier to determine whether the current day is "in calendar" or not.

The present_value is a Boolean that is true precisely when today's date matches at least one entry in the date_list. The list can contain both concrete dates and recurring patterns, giving a very flexible way to define "every third Wednesday in November", date ranges, etc.

Object Description (ASHRAE 135)

The Calendar object type defines a standardized object used to describe a list of calendar dates, which might be thought of as "holidays", "special events", or simply as a list of dates.

Behaviour and Operation

Calendar objects are passive date-list containers. The date_list property (containing concrete dates, DateRanges, WeekNDay patterns, etc.) is normally configured at creation time or by a configuration tool / operator and then left alone. The local timekeeping subsystem evaluates the list against the current date to decide whether the calendar is "active".

The present_value is true when the current local date matches any entry. The device must keep the system clock (and thus the evaluation) accurate. The calendar is not a control point but a reference used by Schedules and other objects.

Developer Implementation Notes (geared to device server / application authors)

The generated code handles storage + basic mechanics (validation, implicit_relationships, readonly annotations as hints to your server, etc.). You must drive "special" live properties and side effects yourself, analogous to maintaining present_value on inputs via update_property/3 (never direct mutation). Read notes below + generated tables for details.

Special / live properties and expected developer behaviour

  • present_value: "Is today a special day per this calendar?" (yes/no for use by Schedules etc.). Dev must: This is computed live. Your time task (or the Schedules that reference calendars) must, on every date change (midnight or DST etc.) or slow poll, re-evaluate every BACnet.Protocol.CalendarEntry in date_list against the current wall date (handling wildcards, ranges, WeekNDay). Update present_value via update_property/3 when it changes.

  • date_list: The definition of special days. Dev must: Populate at creation/config (by workstation, client, or your setup). Clients can rewrite it at runtime (you may restrict in Write handler or require special mode). When it changes, immediately re-eval present_value for "today".

A Calendar is a shared date predicate. Any number of Schedules (and potentially your own custom logic) can ask "is today one of the special days defined by this calendar?" by simply reading its present_value.

Wildcards and patterns: The power of a calendar comes from the rich wildcard rules (month 13 = odd, 14 = even, day-of-month 32 = last day, weekday 7 = "any", year = unspecified, etc.). Your evaluation code must implement the full BACnet date matching rules when comparing a BACnet.Protocol.CalendarEntry against the current date.

Remote calendars: A Schedule can reference a Calendar on another device (via the object identifier in an exception). In that case the Schedule's evaluation engine must read the remote calendar's present_value.

Writing the date_list: Because it is a normal property (an array of CalendarEntry), a client can completely rewrite the holidays at runtime.

Calendars are the classic example of a "pure reference object" whose only job is to answer a yes/no question that many other objects need.

Examples

Creating a Calendar:

iex> {:ok, cal} = BACnet.Protocol.ObjectTypes.Calendar.create(500, "Holidays", %{}); cal.object_name
"Holidays"

See Also

The following part has been automatically generated.

Click to expand This module defines a BACnet object of the type `calendar`. The following properties are defined: | Property | Revision | Required | Readonly | Protected | Intrinsic | |----------|----------|----------|----------|-----------|-----------| | date_list | | X | | | | | description | | | | | | | object_instance | | X | X | | | | object_name | | X | X | | | | present_value | | X | | | | | profile_location | 19 | | | | | | profile_name | | | | | | | tags | 19 | | | | | The following properties have additional semantics: | Property | Has Default | Has Init | Implicit Relationships | Validators | Annotations | |----------|-------------|----------|------------------------|------------|-------------| | date_list | X | | | | | | profile_location | | | | Fun | `revision: 19` | | tags | | | | | `revision: 19` | The following table shows the default values and/or init functions: | Property | Default Value | Init Function | |----------|---------------|---------------| | date_list | `[]` | |

Summary

Types

common_object_opts()

Common object options for creation - all are optional.

object_opts()

Options accepted when creating or configuring a Calendar object.

property_name()

Available property names for this object.

property_update_error()

The structure for property errors.

t()

Represents a Calendar object. All keys should be treated as read-only, all updates should go only through update_property/3.

Functions

add_property(object, property, value)

Adds an optional property to an object. Remote objects can not be mutated using this operation.

create(instance_number, object_name, properties \\ %{}, opts \\ [])

Creates a new object struct with the defined properties. Optional properties are not created when not given, only required, given and dependency properties are created. Properties with a value of nil are ignored.

get_all_properties()

Auto generated function to get the names of all properties this object supports.

get_annotation(name)

Auto generated function to get the annotations for the given property name.

get_annotations()

Auto generated function to get the list of annotations for each property.

get_cov_properties()

Auto generated function to get the names of properties used for COV reporting.

get_intrinsic_properties()

Auto generated function to get the names of intrinsic properties.

get_object_identifier(object)

Get the BACnet object identifier.

get_optional_properties()

Auto generated function to get the names of optional properties.

get_properties(object)

Get the list of properties the object has.

get_properties_type_map()

Auto generated function to get a map of property name to type.

get_property(object, property)

Get a property's value from an object.

get_protected_properties()

Auto generated function to get the names of protected properties.

get_readonly_properties()

Auto generated function to get the names of readonly properties.

get_required_properties()

Auto generated function to get the names of required properties.

has_property?(object, property)

Checks if the given object has the given property.

property_writable?(object, property)

Checks if the given property is writable.

remove_property(object, property)

Removes an optional property from an object. This function is idempotent. Remote objects can not be mutated using this operation.

supports_intrinsic()

Auto generated function to check whether the object type supports intrinsic reporting.

update_property(object, property, value)

Updates a property of an object.

Types

common_object_opts()

@type common_object_opts() ::
  {:allow_numeric_constants, boolean()}
  | {:allow_unknown_properties, boolean()}
  | {:ignore_unknown_properties, boolean()}
  | {:revision, BACnet.Protocol.Constants.protocol_revision()}
  | {:skip_property_validation_remote_object, boolean() | :value}

Common object options for creation - all are optional.

  • allow_numeric_constants - Constants are atoms and thus unknown constants or vendor extensions are integers and thus are rejected. Enabling this option will allow integers (non_neg_integer()) for properties with a Constants.type() spec.
  • allow_unknown_properties - Properties that are unknown to the object implementation are usually rejected. With this option, unknown properties (numeric identifiers usually means we dont know them) are accepted and put into a separate map. This does mean we can not validate or write them. Types of the values can be anything at this point. While you can read unknown properties with atom or integer as property identifier, you can only remove numeric unknown property identifiers from an object. Property identifiers of type atom are only accepted, if it is a remote object (object implementation is only enforced if it is a local object). Numeric property identifiers are accepted regardless of remote object or not. For remote objects, this means you have to write "raw values" (usually Encoding structs).
  • ignore_unknown_properties - Properties that are unknown to the object implementation are usually rejected. With this option, unknown properties get ignored, as if they were not specified.
  • revision - The BACnet protocol revision to check required properties against. Optional properties are regardless of revision available. See BACnet.Protocol.Constants.protocol_revision/0 for the available revisions.
  • skip_property_validation_remote_object - Skips property validation for remote objects. Sometimes it is possible that the value is invalid as per BACnet specification (i.e. value 0 for a multistate object), but you still want those to be represented. Value true neither type nor value are validated. Value :value means the type is still validated and only the value validator is not run (if present). The property's validator_fun will also be skipped.

object_opts()

@type object_opts() :: common_object_opts()

Options accepted when creating or configuring a Calendar object.

property_name()

@type property_name() ::
  :date_list
  | :description
  | :object_instance
  | :object_name
  | :present_value
  | :profile_location
  | :profile_name
  | :tags

Available property names for this object.

property_update_error()

@type property_update_error() ::
  {:error,
   {error :: atom(),
    property :: BACnet.Protocol.Constants.property_identifier()}}

The structure for property errors.

t()

@type t() :: %BACnet.Protocol.ObjectTypes.Calendar{
  _metadata: internal_metadata(),
  _unknown_properties: %{
    optional(atom() | non_neg_integer()) =>
      term()
      | BACnet.Protocol.ApplicationTags.Encoding.t()
      | [BACnet.Protocol.ApplicationTags.Encoding.t()]
  },
  date_list: [BACnet.Protocol.CalendarEntry.t()],
  description: String.t() | nil,
  object_instance: non_neg_integer(),
  object_name: String.t(),
  present_value: boolean(),
  profile_location: String.t() | nil,
  profile_name: String.t() | nil,
  tags: BACnet.Protocol.BACnetArray.t(BACnet.Protocol.NameValue.t()) | nil
}

Represents a Calendar object. All keys should be treated as read-only, all updates should go only through update_property/3.

Functions

add_property(object, property, value)

@spec add_property(t(), BACnet.Protocol.Constants.property_identifier(), term()) ::
  {:ok, t()} | property_update_error()

Adds an optional property to an object. Remote objects can not be mutated using this operation.

Please note that properties of services can not be dynamically added and instead the object must be newly created using create/4.

create(instance_number, object_name, properties \\ %{}, opts \\ [])

@spec create(
  non_neg_integer(),
  String.t(),
  %{optional(property_name() | atom() | non_neg_integer()) => term()},
  [object_opts() | internal_metadata()]
) :: {:ok, t()} | property_update_error()

Creates a new object struct with the defined properties. Optional properties are not created when not given, only required, given and dependency properties are created. Properties with a value of nil are ignored.

Only properties that are required for specific services (i.e. Intrinsic Reporting) are automatically created.

get_all_properties()

@spec get_all_properties() :: [BACnet.Protocol.Constants.property_identifier()]

Auto generated function to get the names of all properties this object supports.

get_annotation(name)

@spec get_annotation(property_name()) :: [term()]

Auto generated function to get the annotations for the given property name.

get_annotations()

@spec get_annotations() :: [{name :: property_name(), values :: [term()]}]

Auto generated function to get the list of annotations for each property.

get_cov_properties()

@spec get_cov_properties() :: [BACnet.Protocol.Constants.property_identifier()]

Auto generated function to get the names of properties used for COV reporting.

get_intrinsic_properties()

@spec get_intrinsic_properties() :: [BACnet.Protocol.Constants.property_identifier()]

Auto generated function to get the names of intrinsic properties.

get_object_identifier(object)

@spec get_object_identifier(t()) :: BACnet.Protocol.ObjectIdentifier.t()

Get the BACnet object identifier.

get_optional_properties()

@spec get_optional_properties() :: [BACnet.Protocol.Constants.property_identifier()]

Auto generated function to get the names of optional properties.

get_properties(object)

@spec get_properties(t()) :: [BACnet.Protocol.Constants.property_identifier()]

Get the list of properties the object has.

get_properties_type_map()

@spec get_properties_type_map() :: map()

Auto generated function to get a map of property name to type.

get_property(object, property)

@spec get_property(
  t(),
  BACnet.Protocol.Constants.property_identifier() | non_neg_integer()
) ::
  {:ok, term()} | property_update_error()

Get a property's value from an object.

get_protected_properties()

@spec get_protected_properties() :: [BACnet.Protocol.Constants.property_identifier()]

Auto generated function to get the names of protected properties.

Protected is an annotation and the object modules prevent writing to this property directly in code. The protected properties are either written on creation or updated automatically depending on other properties being written to. Some properties are only written once at creation and never updated.

get_readonly_properties()

@spec get_readonly_properties() :: [BACnet.Protocol.Constants.property_identifier()]

Auto generated function to get the names of readonly properties.

Readonly is only an annotation that the property should be write protected on the BACnet side, there is no actual write protection in the object. This is a hint to the device server. If you need actual write protection, see protected.

get_required_properties()

@spec get_required_properties() :: [BACnet.Protocol.Constants.property_identifier()]

Auto generated function to get the names of required properties.

has_property?(object, property)

@spec has_property?(t(), BACnet.Protocol.Constants.property_identifier()) :: boolean()

Checks if the given object has the given property.

See BACnet.Protocol.ObjectsUtility.has_property?/2 for implementation details.

property_writable?(object, property)

@spec property_writable?(t(), BACnet.Protocol.Constants.property_identifier()) ::
  boolean()

Checks if the given property is writable.

Check BACnet.Protocol.ObjectsUtility.property_writable?/2 for a basic run-down.

remove_property(object, property)

@spec remove_property(
  t(),
  BACnet.Protocol.Constants.property_identifier() | non_neg_integer()
) ::
  {:ok, t()} | property_update_error()

Removes an optional property from an object. This function is idempotent. Remote objects can not be mutated using this operation.

Please note that properties of services can not be dynamically removed and instead the object must be newly created using create/4. Required properties can not be removed.

supports_intrinsic()

@spec supports_intrinsic() :: boolean()

Auto generated function to check whether the object type supports intrinsic reporting.

update_property(object, property, value)

@spec update_property(t(), BACnet.Protocol.Constants.property_identifier(), term()) ::
  {:ok, t()} | property_update_error()

Updates a property of an object.