Thanks for the info, Brian. I'll check the console with the new server-side
impl (should affect the transaction attributes only, but will also do some
On Wed, Nov 23, 2016 at 12:50 AM, Brian Stansberry <
This PR is merged so this will be there once this week’s core release is
merged into full (probably by Monday).
> On Sep 7, 2016, at 3:59 PM, Brian Stansberry <
> PR for this: https://github.com/wildfly/wildfly-core/pull/1781
>> On Sep 6, 2016, at 1:56 PM, Brian Stansberry <
>>> On Sep 6, 2016, at 11:58 AM, Harald Pehl <hpehl(a)redhat.com> wrote:
>>> Thanks Brian for bringing this up. Everything which makes the metadata
more consistent helps management client such as HAL. And as more and more
forms are based on MBUI (generated based on the r-r-d metadata) this is
even more important.
>>> Right now we already have some logic behind the 'nillable' and
'alternatives' attributes to decide whether an attribute is required or not:
>>> boolean required = attributeDescription.hasDefined("nillable")
>>> if (attributeDescription.hasDefined("alternatives") &&
>>> required = false;
>> Ah, good. So my proposed change to how nillable is calculated shouldn’t
change the final result you get above for your required variable. :) So
once I do what I propose on the server side you can adapt to it when
>>> In HAL we use attribute descriptions to add new resources and to
modify existing resources. For the former we rely on the
'request-properties' node of the add operation description. The latter uses
the 'attributes' node of the r-r-d op. If we want to make changes, it's
important to be consistent and apply them to both nodes. Right now these
two nodes already have slightly different attributes: The
'request-properties' already contain a 'required' attribute whereas the
>> Yes, this inconsistency is part of the overall task of WFCORE-1556. The
actual metadata we generate doesn’t comply with the spec in [a] and [b] and
then the spec itself is inconsistent between those two sections in how it
deals with “required” vs “nillable”. And there’s no reason for that.
>> [a] https://docs.jboss.org/author/display/WFLY/Admin+Guide#AdminGuide-
>> [b] https://docs.jboss.org/author/display/WFLY/Admin+Guide#AdminGuide-
>>> The proposal makes sense to me and the impact on HAL should be
minimal. Some questions I have:
>>> 1. Will the metadata contain both 'nillable' and 'required'?
'required' being the leading attribute and 'nillable' being deprecated
still there for backwards compability?
>> It will contain both. I wouldn’t characterize either as leading or
deprecated. Rather they have different functions:
>> required — indicates the attribute/parameter represents something that
must be configured in some way. But configuring one of the ‘alternatives’
>> nillable — indicates that attribute/parameter may have an undefined
value for some reason
>> So nillable is useful to a client simply wanting to know whether it
needs to deal with ‘undefined’. A more sophisticated client would use
‘required’ plus ‘alternatives’.
>>> 2. Will your proposal also cover the 'request-properties' for the
>> Yes, they will be made consistent, with all attribute and parameter
descriptions exposing the same metadata fields with the same conceptual
>> In terms of the server side implementation, for almost all add
operations, the same AttributeDefinition instance is used for generating
both the attribute description and the add parameter description. And for
all parameter descriptions we use the same AttributeDefinition classes that
we use for resource attributes, so the behavior we put in the AD class will
apply to both.
>>> On Tue, Sep 6, 2016 at 3:10 PM, Brian Stansberry <
>>> It’s not an uncommon thing to have a management attribute A that is
required; i.e. must be set, but also has an alternative attribute B, where
setting B satisfies the requirement for A, making an undefined value for A
legal. We’re not handling that correctly and I want to fix it. But
fixing it will require some coordination with the HAL console.
>>> Right now the way AttributeDefinition building works it’s not
practical to declare that an attribute is required but only if no
alternative is set. So instead attributes are declared as if they aren’t
really required. This leads to less than helpful input validation, e.g. 
and , since the attribute definition is imprecise.
>>> The change I’d like to make will alter the read-resource-description
output for 4 attributes, changing the value of the ‘nillable’ description
from ‘false’ to ‘true’ so I want to coordinate that with the console team.
>>> Long version
>>> Harald and Claudio you guys are the main audience here. :)
>>> For even longer version see description and comments on .
>>> In a nutshell, if devs set the ‘allowNull’ property on an
AttributeDefinition to ‘true’, the r-r-d output for the attribute has
“nillable” => true. But there is no way to say “allowNull but only if an
alternative is set.” So people are setting “allowNull” to true even if the
attribute should be set in the absence of alternatives. And HAL has no
metadata available to it to tell users they *must* set one of the
alternatives. So I want to:
>>> 1) Add a setRequired(boolean) method to the AD builders where the fact
that it means “must be defined if no alternative is defined” is explicitly
>>> 2) @Deprecate setAllowNull and point to setRequired
>>> 3) Clarify the meaning of setAllowNull(true) as being the same as
>>> 4) Change the builder ‘allowNull’ constructor param name to “optional”
and document its meaning as “allowing undefined values even in the absence
of defined alternatives”. I could call the param ‘notRequired’ which is
clearer in meaning but odd.
>>> Then I will add a new ‘required’ metadata field to the r-r-d output
and change the impl of the existing ’nillable’ metadata to a logical
“!required || (alternatives != null && alternatives.length > 0)”
>>> This will result in a change in the ‘nillable’ value for 4 attributes
in the WildFly model from ‘false’ to ’true':
>>> /subsystem=transactions PROCESS_ID_SOCKET_BINDING and PROCESS_ID_UUID
USERNAME_FILTER and ADVANCED_FILTER
>>> The latter two are not exposed in the console so the issue really is
the two transaction attributes.
>>> I haven’t checked other subsystems in things like Teiid or JDG, but if
there are only 4 in all of WildFly I doubt there are many.
>>> Also, if people start using the new behavior to correct problems like
 and  people may expect the console to understand and reflect the
concept of “required but only if there is no alternative’.
>>>  https://issues.jboss.org/browse/WFCORE-1556
>>>  https://issues.jboss.org/browse/WFLY-6608
>>>  https://issues.jboss.org/browse/WFLY-6607
>>> Brian Stansberry
>>> Manager, Senior Principal Software Engineer
>>> JBoss by Red Hat
>>> wildfly-dev mailing list
>>> Harald Pehl
>>> JBoss by Red Hat
>> Brian Stansberry
>> Manager, Senior Principal Software Engineer
>> JBoss by Red Hat
>> wildfly-dev mailing list
> Brian Stansberry
> Manager, Senior Principal Software Engineer
> JBoss by Red Hat
> wildfly-dev mailing list
Manager, Senior Principal Software Engineer
JBoss by Red Hat