IBM Integration Bus, Version 10.0.0.1 Operating Systems: AIX, HP-Itanium, Linux, Solaris, Windows, z/OS


Using filters in content-based filtering

Content based filters are specified as ESQL expressions.

Field references

Read syntax diagramSkip visual syntax diagram
                         .-"."---------------------.   
                         V                         |   
>>-+------------------+----field name--+---------+-+-----------><
   '-Correlation Name-'                '-[INDEX]-'     

The field references that can be used in filters for content based filtering form a subset of those supported by the Filter node. As with the Filter node, to reference a field in a filter, you must specify a path. Each element of the path consists of a, possibly indexed, field name.

The syntax of a field reference is shown above, where field name and Correlation Name are identifiers. These identifiers represent all messages as a hierarchical syntax element tree. Each path identifies a route through that tree, which leads to a particular syntax element, starting from one of the predefined correlation names that refer to fixed points that every message has. The following correlation names are supported for content based filtering:

Correlation name Purpose
Root Identifies the root of a published message.
Properties Identifies the portion of the message in which the standard properties of a message lie.
Body Identifies the last child of the root of the message, which is usually, but not always, the application data that follows any headers.

Here are some examples of field references, together with their meanings:

Field reference Purpose
Body.Person.Address Refers to the first Address field in the Person entity in the body of the message.
Properties.Topic Refers to the "Topic" field in the standard properties of a message.
Root.MQMD.UserIdentifier Refers to the UserIdentifier field in the MQMD of the message.

Note that path elements of "*" and the array index "LAST" are not supported in the filters.


bq13350_.htm | Last updated 2015-05-28 20:53:04