<event-filter>
Used in subscriptions for receiving events. Allows matching on any and all header properties (see <local-event>
).
In essence, the filter is a list of header comparators (see below), to be treated as a disjunction (OR).
Attributes
NAME |
TYPE |
DEFAULT VALUE |
DESCRIPTION |
---|---|---|---|
topic |
|
|
topic to which to subscribe for events; if UNSPECIFIED, all events received on other subscriptions will qualify |
Elements
TAG |
TYPE |
COUNT |
DESCRIPTION |
---|---|---|---|
|
|
0:N |
filter subpart enabling matching on header properties (see below) |
|
|
0:1 |
specify only these connections (= URI strings; default behavior is all connections) |
Examples
<event-header-comparator>
Filter for matching event headers. Treated as a conjunction (AND) of constraints.
The topic and key will always be compared for equality; timestamps and header properties can be given a string comparator (see below) with the default being EQ. NULL
and NOT_NULL
can be used as the value of property comparisons. Property comparators are stored in lexicographically sorted order.
Attributes
NAME |
TYPE |
DEFAULT VALUE |
DESCRIPTION |
---|---|---|---|
key |
|
|
a unique identifier for the subject of the event; usually a string representation of a ParsedLocalEventKey |
timestamp |
|
|
timestamp to use in comparison |
timestampComparator |
|
|
string comparator (see below) to use with timestamp comparison, if any |
Elements
TAG |
TYPE |
COUNT |
DESCRIPTION |
---|---|---|---|
|
|
0:N |
describes a single match constraint (see below) |
<property-comparator>
The named header property of the event is accessed for its value, which is compared to the given value using the comparator indicated. Types are limited to strings and primitives.
NAME |
TYPE |
DEFAULT VALUE |
DESCRIPTION |
---|---|---|---|
name |
|
|
name of header property |
value |
|
|
string representation of the value to compare header property value to |
type |
|
|
type of the value |
comparator |
|
|
string comparator to use (see below) |