This section describes commands that are common to most item types. The sections that describe particular item types define the subset of these common item commands applicable to a particular item type.

item# attribute [name [value]]

The item# attribute command allows you to save item specific data in item attributes. If called without any arguments, all existing attribute names for this item will be returned. If called with a name argument, the current value of the attribute will be returned. Non-existing attributes do not produce an error. Instead, an empty string is returned. Evaluating the item# attribute command with a name and a value argument causes the value to be saved in the item attribute name.

The item# bind command binds a Tcl script to an event. A binding is created by evaluating this command with a pattern, which is later matched against event tags. A successful match will trigger the evaluation of the Tcl script bound to the pattern. Pattern matching is done as described in the documentation for the Tcl string match command. It is possible to create multiple bindings for the same pattern. The item# bind command returns a handle for the new binding.

The item# cget command retrieves the value of an item option given by option. See the description of item options below for more details.

The item# configure command allows you to query or change the current configuration options of a item instance. See the description of item options below for more details.

The item# destroy command destroys the item. All data associated with the item is deleted.

The item dump command returns a Tcl script which can be evaluated to create a copy of the current item.

The item# info command returns the list of handles that are related to this item. The optional pattern is used to select a subset. The subject events returns the events associated with the item. The pattern is matched against the event name. The subject messages returns the message handles associated with the item. The pat-tern is matched against the message tag. The subject bindings return the list of binding handles for the item. The pattern is matched against the binding pat-tern. The subject member, who is only supported by container objects, returns the list of members of this item. The pattern is ignored in this case.

The item# map command returns the map which controls this item. Items are always associated with a single map and items can not move directly from one map to another.

The item# message command creates a message which contains the given text. The message is kept in memory until it expires. Messages might be appended to files if the message tag matches one of the patterns contained in the value of the -store item option and if the value -f the -path item option is not empty.
Message are used to report statistics or events. Every message is automatically augmented with a time-stamp. However, many statistics or events are bound to a time interval. The -interval option allows you to specify such a time interval in seconds. The interval value is set to 0 if this option is missing.
Messages can also be used to influence the health of the item. The value of the -health option must be in the range of -100..100 and indicates a negative or positive health change. The exact computation of the health of the item uses these indications to derive a new health value whenever the item ticks. The health value is be set to 0 if this option is missing.

The item# move command moves the item from the current position on the virtual map by adding x and y to the current position. The command returns the new position as a list containing the x and the y position. The item# move command only returns the current position if the optional arguments are missing.

The item# raise command raises an event on the item. The event type is identified by the string tag. Additional arguments, which describe event details, can be supplied in the optional args parameter. The item# raise command returns a handle for the new event. This handle can be used later to retrieve information about this specific event or to delete this event.

The item# type command returns the type of an item. See below for a description of item types.