In Babelway interface, it is possible to set up validations at message definition level.

You can set up validation rules for incoming and/or outgoing messages. These validations will be performed at runtime on messages.

To add validation rules, right click on a node in message definition window and select Add Validations... submenu. There are 3 basic validation rules that you can set up directly. In addition, you can also define your own rules in Xpath language.

Several validation rules may be applied to a same node. For example, using together a Max Length and a Min Length rule makes it easy to check that a node value has a specific length.

Once a validation rule has been added to a field, it will appears under the Validations section of message node. It can be removed by right-clicking on the validation rule and selecting the Delete command.

Example of Xpath validation rule:

string-length()>4

matches(.,"\d+") to validate if this field is only numeric 

Example of cross field validation rule:

For XML like this

<item>
<price>456</price>
<tax>123</tax>
</item>

You can write Cross field validation like

price > tax