API

object Data

The most basic implementation of a DML Object. It allows to add properties, events and functions and can hold other Objects and Behaviours as children. It has no other special functionality. It is intended as dml grouping object as well as base object for all other data types Data does allow for children. Note that children are static values, they cannot change at runtime. Hence they are different to dynamic objects as are possible with Maps etc. Children are used purely for the static DML hirarchy.

property string name [constant]

A property defining the name of the object. The name can than be used to access in the hirarchy, either in JavaScript code or as WAMP uri. It is mandatory to set the name of each object.

property Data parent [constant]

The parent object of the object. The value is null for the toplevel object.

property [Data] children [constant]

A list of all children the Data object has. Note that this are only the children defined in the DML file itself, not the dynamic subobjects some types can add, like maps entries.

event onBeforePropertyChange

Emitted bevore a property of the object changes. At time of emit the property still has its old value.

Arguments

• Property (string) – Name of the property thats about to be changed

event onPropertyChanged

Emitted when a property was changed. The value of the property is already the new one when emitted.

Arguments

• Property (string) – Name of the property thats was changed

event onCreated

Emitted after the object was created and fully setup. It will be emitted only dynamically created objects, for example when used as value in Maps, and not the ones in the static DML hirarchy.

event onRemove

Emitted after the object is about to be removed. At the time of emitting the object is still fully setup and accessible, the removing will happen after all handlers have been executed. As static hirarchy objects cannot be removed this event will be emitted only for dynamically created objects, for example when used as value in Maps etc.

event onBeforeChange

This is a general event, emitted bevore the object itself changes, no matter what the changes are. This is not emitted for changed properties, there is a custom event for that, but if the objects content is manipulated. This means that for a Data object it will never be emitted, as it does not have any object content, but it may be emitted for derived object types like maps.

Note

Most derived classes that emit this event will also have custom events that are more specialized for the eexact changes that happend.

event onChanged

This is a general event, emitted after the object has changed, no matter what the changes are. This is not emitted for changed properties, there is a custom event for that, but if the objects content was manipulated. This means that for a Data object it will never be emitted, as it does not have any object content, but it may be emitted for derived object types like maps.

Note

Most derived classes that emit this event will also have custom events that are more specialized for the eexact changes that happend.

object Map(Data)

Mapping from any key type to any other type. A Map is a standart datatype as avilable in all programming languages, sometimes nown as Dictionary.

property key key [constant]

A property defining the datatype of the maps keys. Allowed values are all key datatypes like int and string.

Default

string

property type value [constant]

A property defining the datatype of the maps values. Allowed values are dml types including var. This allows for nesting objects by making the map value a new subtype.

Default

none

function Length()

Returns the length of the map, which is defined as the number of keys.

Return

• length (int) – The length of the map

function Keys()

Provides access to all keys in the map. The type of the keys is dependend on the Maps key property. If called from javascript, an unmutable array is returned, if called via WAMP API it will be the list type that is supported by the calling language (e.g. List for python)

Return

• keys (List[any]) – All keys that are in the map

function Has(key)

Checks if the given key is available in the Map. The key must be of correct type, e.g. if the Map key property defines int, the key must be an integer and not a string describing the integer (like 1 and not “1”). This is different to how the Map handels WAMP Uri for accessing its values, as there the key must always be given as string.

Throws

If key is of wrong type

Return

• has (bool) – True if the key is available in the Map

function Get(key)

Returns the value currently stored for the given key. If the Maps value type is a Object it will return the object itself when called from JavaScript, and the object ID if called by WAMP Api.

Throws

If key is not available

Throws

If key is of wrong type (must be equal to key property)

Return

• value (any) – The value for the key

function Set(key, value)

Sets the value for the given key. If already available it the old value will be overriden, otherwise it will be newly created and set to value. Key and value type need to be consitent with the Maps defining properties.

If the Map value type is a object, this function will fail. It is not possible, to set it to a different object or override it once created. Use the New function for creating the object for a given key.

Throws

If key is of wrong type (must be equal to key property)

Throws

If value is of wrong type (must be equal to value property)

Throws

If value type of Map is a Object

function New(key)

Creates a new entry with the given key and sets it to the value types default, e.g. 0 for int, “” for string etc. If the value type is a Object it will be fully setup, and its onCreated event will be called. The New function is the only way to create a key entry if value type is an Object, as Set will fail in this case.

Throws

If key already exists

Throws

If key is of wrong type (must be equal to key property)

Return

• value (any) – The stored value for given key

function Remove(key)

Removes the key from the map. If value type is a Object, its onRemove event will be called and afterards will be deleted.

Throws

If key does not exist

Throws

If key is of wrong type (must be equal to key property)

behaviour Behaviour [abstract]

Base class for all behaviours, adding common properties and events. It cannot be used directly, only behaviours derived from it. It does add the possibility to add custom properties, events and functions. Children are not allowed.

property string name [constant]

A property defining the name of the behaviour. The name can be used to access ut in the hirarchy, either in JavaScript code or as WAMP uri. It is mandatory to set the name of each behaviour.

property Data parent [constant]

The parent object of the behaviour, the one which it extends.

property bool recursive [constant]

Defines if the behaviour is applied recursively for all children and subobjects of the behaviours parent. For example, if a behaviour is added to a Map Object, it may watch for changes in that object. If recursive is true, it will also look for all changes in any children or value objects of that Map.

Default

false

event onBeforePropertyChange

Emitted bevore a property of the object changes. At time of emit the property still has its old value.

Arguments

• Property (string) – Name of the property thats about to be changed

event onPropertyChanged

Emitted when a property was changed. The value of the property is already the new one when emitted.

Arguments

• Property (string) – Name of the property thats was changed

behaviour Continuity(Behaviour)

The continuity behaviour helps you to ensure continious updates to a object. The idea is to make updates on a object only possible, if they are based on the latest available data.

To ensure this, the caller, the one who wants to make a change, need to show that he based his update on the currently existing object. For this, the behaviour adds the state property to the object which represents the current state as a integer. When a set of changes is finished, the state gets incremented (by the user or automatically). Any caller needs to ensure, that his change is based on the currently available data by providing his last state as integer. If this provided known state matches the current state value, the update is allowed, and if it does not match, the update fails.

..note:: The state increment happens after all user code is executed. Calling “Increment” on a

continuity behaviour marks that object for state increment but does not do it directly. It is only done just before finishing the WAMP api call. The same holds for automatic increments.

behaviour Transaction(Behaviour)

Defines how a Object behaves in transactions. With this behaviour defined in a Object it will become part of the current transaction when a change occurs. If any other user tries to edit it an error will be raised and the action fails.

Any change within the object does trigger the transaction behaviour, be it a set property or any Object internal change, like a new entry in a Map. If recursive is true, the same holds for any change in a child- or subobject. Note that a change in a child will not add the child to the current transaction, but the Object which has the behaviour defined.

function Add()

Adds the Object to the current transaction. If the Object is already part of the current transaction nothing happens, and no error is thrown.

Throws

If no transaction is open for current user

Throws

If Object is already part of a transaction of annother user

function InTransaction()

Checks if the Object is currently part in any transaction

Return

• IsPart (bool) – True if in a transaction, false otherwise

function InCurrentTransaction()

Checks if the Object is currently part in the users transaction

Return

• IsPart (bool) – True if in users transaction, false otherwise

function InDifferentTransaction()

Checks if the Object is currently part in a transaction of annother user

Return

• IsPart (bool) – True if in other users transaction, false otherwise

function CanBeAdded() [virtual]

Allows custom logic for checking if the Object is allowed to take part in the current transaction. To be overriden and implemented by the user. If false is returned, the action that lead to the Object being added to the transaction fails. Note that it is not needed to check if the Object is already part of annother transaction, this is still done internally. This function is to be used for custom logic only.

Return

• Possible (bool) – True if it is allowed to add object to current transaction

function CanBeClosed() [virtual]

Allows custom logic for checking if the transaction, in which the Object takes part, is allowed to be closed. To be overriden and implemented by the user. If false is returned, closing the transaction fails and it stays open. The implementation should make sure that the user is informed about the reasons, so that he can correct it bevore trying to close the transaction again.

Note

This function is not called for aborting transactions. Aborting cannot be prevented.

Return

• Possible (bool) – True if it is allowed to close the current transaction

function DependentObjects() [virtual]

Allows custom logic for defining dependent Objeccts. To be overriden and implemented by the user. This function will be called when the Object is added to the transaction, and the list of returned Objects will then be added to the current transaction too.

Return

• Dependencies (List[Objecct]) – All Objects that need to also be part of the transaction

event onParticipation

Emitted when the Object becomes part of the users current transaction. If a JavaScript callback for this event throws an error the adding of the Object fails, as well as the user action triggering it. Hence this can be used the same way as overriding CanBeAdded

event onClosing

Emitted when current transaction, of which the Object is a part, is closed. If a JavaScript callback for this event throws an error the transaction closing fails, as well as the user action triggering it. Hence this can be used the same way as overriding CanBeClosed

event onAborting

Emitted when current transaction, of which the Object is a part, is aborted. Errors in callbacks ar ignored, as aborting cannot be stopped.

event onFailure

Emitted when adding the object to the current transaction fails, independent of the reason for the fail.

Arguments

• error (str) – The error message describing why it failed

behaviour PartialTransaction(Behaviour)

Defines how the objects individual keys behaves in transactions. With this behaviour defined in a object its keys can become part of that transaction. A key is any identifier pointing to data, like a property name, a number for a Vector or a key for a map. If the behaviour is recursive keys can also be stacked, like childname.mapkey

Any change within the object does trigger the transaction behaviour, be it a set property or any Object internal change, like a new entry in a Map. If recursive is true, the same holds for any change in a child- or subobject. Note that a change in a child will not add the child to the current transaction, but the Object which has the behaviour defined.

Note

Keys are relative paths from the behaviours parent object, e.g. MyChild.myProperty