1 Reply Latest reply: Jul 14, 2010 9:47 AM by Jesper Pedersen RSS

Metadata design - xsds

Stefano Maestri Expert

Hi All,

 

I'm designing our new metadatas layer and I've imported in the projects XSDs form jboss-metadata-rar.

 

I've started with jboss-ra_2_0.xsd and I've already done some changes to that one I'd like to share with you because it would guidelines I'd like to follow in next future for our own XSDs (i.e. not included in JCA specs):

 

diff --git a/common/src/main/resources/schema/jboss-ra_2_0.xsd b/common/src/main/resources/schema/jboss-ra_2_0.xsd
index b8f86cc..3b53927 100644
--- a/common/src/main/resources/schema/jboss-ra_2_0.xsd
+++ b/common/src/main/resources/schema/jboss-ra_2_0.xsd
@@ -5,12 +5,9 @@
     xmlns:javaee="http://java.sun.com/xml/ns/javaee"
     elementFormDefault="qualified" attributeFormDefault="unqualified" version="2.0">
 
-
-    <xs:import namespace="http://java.sun.com/xml/ns/javaee" schemaLocation="http://java.sun.com/xml/ns/javaee/javaee_5.xsd"/>
-    
-    <xs:element name="jboss-ra" type="ra:jbossRaType"/>                              
+    <xs:element name="jboss-ra" type="ra:jboss-ra-type"/>                              
     
-    <xs:complexType name="jbossRaType">           
+    <xs:complexType name="jboss-ra-type">           
         
         <xs:sequence>
             <xs:element name="ra-config-property" type="ra:ra-config-property-type" minOccurs="0" maxOccurs="unbounded"/>  
@@ -26,10 +23,10 @@
 
         <xs:sequence>
             <xs:element name="ra-config-property-name" type="xs:string" minOccurs="1" maxOccurs="1"/>
-            <xs:element name="ra-config-property-type" type="ra:ra-config-property-typeType" minOccurs="1" maxOccurs="1"/>
+            <xs:element name="ra-config-property-type" type="ra:ra-config-property-type-type" minOccurs="1" maxOccurs="1"/>
             <xs:element name="ra-config-property-value" type="xs:string" minOccurs="0" maxOccurs="1"/>
         </xs:sequence>
-        <xs:attribute name="override-element" type="xs:string" default="resourceadapter"/>
+        <xs:attribute name="override-element" type="ra:override-element-type" default="resourceadapter"/>
     </xs:complexType>
 
      <xs:complexType name="bean-validation-groups-type">
@@ -45,31 +42,27 @@
        </xs:sequence>
      </xs:complexType>
      
-      <xs:complexType name="ra-config-property-typeType">
-         <xs:simpleContent>
-           <xs:restriction base="javaee:string">
-              <xs:enumeration value="java.lang.Boolean"/>
-              <xs:enumeration value="java.lang.String"/>
-              <xs:enumeration value="java.lang.Integer"/>
-              <xs:enumeration value="java.lang.Double"/>
-              <xs:enumeration value="java.lang.Byte"/>
-              <xs:enumeration value="java.lang.Short"/>
-              <xs:enumeration value="java.lang.Long"/>
-              <xs:enumeration value="java.lang.Float"/>
-              <xs:enumeration value="java.lang.Character"/>
-           </xs:restriction>
-         </xs:simpleContent>
-      </xs:complexType>
+      <xs:simpleType name="ra-config-property-type-type">
+          <xs:restriction base="xs:token">
+            <xs:enumeration value="java.lang.Boolean"/>
+            <xs:enumeration value="java.lang.String"/>
+            <xs:enumeration value="java.lang.Integer"/>
+            <xs:enumeration value="java.lang.Double"/>
+            <xs:enumeration value="java.lang.Byte"/>
+            <xs:enumeration value="java.lang.Short"/>
+            <xs:enumeration value="java.lang.Long"/>
+            <xs:enumeration value="java.lang.Float"/>
+            <xs:enumeration value="java.lang.Character"/>
+          </xs:restriction>
+      </xs:simpleType>
       
-      <xs:complexType name="override-elementType">
-        <xs:simpleContent>
-          <xs:restriction base="javaee:string">
+      <xs:simpleType name="override-element-type">
+          <xs:restriction base="xs:token">
             <xs:enumeration value="connection-definition"/>
             <xs:enumeration value="resourceadapter"/>
             <xs:enumeration value="activationspec"/>
             <xs:enumeration value="adminobject"/>
             <xs:enumeration value="authentication-mechanism"/>
           </xs:restriction>
-        </xs:simpleContent>
-      </xs:complexType>      
+      </xs:simpleType>      
 </xs:schema>

 

As you can see above what I've basically done is

  1. removing dependency from j2ee schema. It was used just for j2ee:string that is an xs:token. I think using xs:token keep xsd more readable and easy to understand. Moreover it is the important to build enumeration type as xs:simpleType and so making possible to use them also for attribute type
  2. Use of simpletype where it is possible for enumeration making possible to use them for attributes type
  3. All element name and type name are lower case

 

I have elaborated a bit more on this xsd, and I think a great enhancement we can is to define type for ra-config-property at xsd level instead of define 2 different element to express value and type. IOW doing this changes to previous xsd

 

diff --git a/common/src/main/resources/schema/jboss-ra_2_0.xsd b/common/src/main/resources/schema/jboss-ra_2_0.xsd
index 08c5e17..58572d9 100644
--- a/common/src/main/resources/schema/jboss-ra_2_0.xsd
+++ b/common/src/main/resources/schema/jboss-ra_2_0.xsd
@@ -23,8 +23,17 @@

         <xs:sequence>
             <xs:element name="ra-config-property-name" type="xs:token" minOccurs="1" maxOccurs="1"/>
-            <xs:element name="ra-config-property-type" type="ra:ra-config-property-type-type" minOccurs="1" maxOccurs="1"/>
-            <xs:element name="ra-config-property-value" type="xs:token" minOccurs="0" maxOccurs="1"/>
+            <xs:choice>
+                <xs:element name="ra-config-property-booelan" type="xs:boolean" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-string" type="xs:string" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-integer" type="xs:integer" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-double" type="xs:double" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-byte" type="xs:byte" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-short" type="xs:short" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-long" type="xs:long" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-float" type="xs:float" minOccurs="0" maxOccurs="1"/>
+                <xs:element name="ra-config-property-char" type="ra:char" minOccurs="0" maxOccurs="1"/>
+            </xs:choice>
         </xs:sequence>
         <xs:attribute name="override-element" type="ra:override-element-type" default="resourceadapter"/>
     </xs:complexType>
@@ -42,20 +51,13 @@
        </xs:sequence>
      </xs:complexType>

-      <xs:simpleType name="ra-config-property-type-type">
-          <xs:restriction base="xs:token">
-            <xs:enumeration value="java.lang.Boolean"/>
-            <xs:enumeration value="java.lang.String"/>
-            <xs:enumeration value="java.lang.Integer"/>
-            <xs:enumeration value="java.lang.Double"/>
-            <xs:enumeration value="java.lang.Byte"/>
-            <xs:enumeration value="java.lang.Short"/>
-            <xs:enumeration value="java.lang.Long"/>
-            <xs:enumeration value="java.lang.Float"/>
-            <xs:enumeration value="java.lang.Character"/>
-          </xs:restriction>
-      </xs:simpleType>
-      
+     <xsi:simpleType name="char">
+      <xsi:restriction base="xsi:string">
+        <xsi:maxLength value="1"/>
+        <xsi:minLength value="1"/>
+      </xsi:restriction>
+    </xsi:simpleType>
+    
       <xs:simpleType name="override-element-type">
           <xs:restriction base="xs:token">
             <xs:enumeration value="connection-definition"/>

 

As you can see the xsd is a bit more verbose, and parsing it will be too. But IMHO it drives to more readable config files and give us the opportunity to effective validate xml and values before èarsing if we decide to.

 

Look forward for your feedback

S

  • 1. Re: Metadata design - xsds
    Jesper Pedersen Master

    Looks good.

     

    A couple of points:

     

    1) Type definitions should be without "-" characters, so it should be "ra:jbossRaType" instead of "ra:jboss-ra-type". Elements are all lower-case with "-"'s.

     

    2) Overriding config-property's should follow the standard ra.xml format with -name, -type and -value -- name and value are mandatory; we can lookup the -type definition

     

    I do agree that we don't have to have the dependency on the JEE schema in this XSD.