Logisland Dynamic Properties
Learn how to use Dynamic Properties in Logisland configurations.
1. Overview
You use components to run jobs in logisland that manipulate records. Those components use properties that you specify in the job configuration file. Some of them are defined in advance by the component’s developer. They got a name and you have to use it to define these properties.
We call those properties static properties.
Some components support dynamic properties. When this is the case, any properties specified in job conf for this component that is not a static property will be used as a dynamic property instead of throwing an error for a bad configuration.
In this section we will talk about those properties and how you can use them.
2. Structure of a dynamic property
Dynamic properties are really just like static properties but build on the fly. It allow to use both the name and the value of the property by the developer. For example instead of specifying :
record.name: myName record.value: myValue
You could specify :
myName: myValue
The advantage is that you can have any number of dynamic property whereas you have to specify in advance all static properties…
3. Usage of a dynamic properties
You can check the documentation of :ref:`com.hurence.logisland.processor.AddFields` processor that we will use in those example.
3.1. Adding a field which is concatenation of two others using '_' as joining string
set those dynamic properties in AddFields processor :
concat2fields: value1
my_countries: 3
my_countries.type: INTThen records processed by this processor would have 2 more fields out of this processors:
-
field 'concat2fields' of type String with value 'value1'
-
field 'my_countries' of type Int with value '3'
By default if no type is specified by a dynamic property it use a type of String or the same type as old value if field already existed and you choose an overwrite policy.
See :ref:`com.hurence.logisland.processor.AddFields` processor doc fore more information.
4. Conclusion
As you can see dynamic properties are very flexible but it’s usage is very dependent of the implementation of the component’s developer.
