[dna-issues] [JBoss JIRA] Commented: (DNA-293) JcrSession creates Property instances that use the PropertyType.UNDEFINED, which is not allowed

[Randall Hauch (JIRA)]

    [ https://jira.jboss.org/jira/browse/DNA-293?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12455505#action_12455505 ] 

Randall Hauch commented on DNA-293:
-----------------------------------

Actually, I just found this in Section 8.5.2.9 of the JSR-170 spec (which is Section 7.5.2.9 of the draft JSR-283 spec), which is about how to deal with property values in SQL queries when the property definition's type is "undefined":

    "When a node type T defines a property P with an UNDEFINED property type this means that two 
    node instances of type T can each have a property called P but with differing property types. 
    In such cases the database view of T is a single column of type VARCHAR (see below). In other 
    words, the different types are converted to strings."

I'm not sure whether this is a better strategy for choosing the actual property type for a Property instance.  It is likely that the SQL query functionality needs to use the PropertyDefinition objects (without the luxury of actual Property instances) to plan queries.


> JcrSession creates Property instances that use the PropertyType.UNDEFINED, which is not allowed
> -----------------------------------------------------------------------------------------------
>
>                 Key: DNA-293
>                 URL: https://jira.jboss.org/jira/browse/DNA-293
>             Project: DNA
>          Issue Type: Bug
>          Components: JCR
>    Affects Versions: 0.3
>            Reporter: Randall Hauch
>            Assignee: Randall Hauch
>             Fix For: 0.4
>
>
> The "undefined" property type is only allowed in property definitions.  According to the JSR-170 specification (Section, 6.2.5):
>     "This constant can be used within a property definition (see 6.7.6 Property Definitions) to specify that the property in 
>     question may be of any type. However, it cannot be the actual type of any property instance. For example it will 
>     never be returned by Property.getType and (in level 2 implementations) it cannot be assigned as the type when 
>     creating a new property."
> When the property definition has a type of "undefined", then we'll need to choose what actual type to use.  There doesn't appear to be any guidance on this in the spec (anybody?), so barring that the most logical approach is probably to look at the first property value.  
> Note that this is one reason why the DNA graph API was designed with the value factories to allow (or encourage) the client to convert the property values to the type desired by the client.  Because of this, it doesn't matter so much what type the value actually is, but rather that it can be converted to the type needed by the user.  So this should make the above assumption (about choosing the property type based upon value) a pretty decent one.

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