Group node properties and children into their own tags.

Make order of elements unimportant.
Remove unused references.

3 files changed, 155 insertions, 120 deletions

diff --git a/data/examples/interface_definition_sample.xml b/data/examples/interface_definition_sample.xml
index e77240b..fe22e17 100644
--- a/data/examples/interface_definition_sample.xml
+++ b/data/examples/interface_definition_sample.xml
@@ -1,15 +1,29 @@
 <?xml version="1.0"?>
 <interfaceDefinition extends="system">
   <node name="login">
-    <tagNode name="user">
-      <helpString>User name</helpString>
-      <constraint>
-        <regex>[a-z][a-zA-Z0-9]+</regex>
-        <errorMessage>User name must start with a letter and consist of letters and digits</errorMessage>
-      </constraint>
-      <leafNode name="full-name">
-        <helpString>User full name</helpString>
+    <children>
+      <tagNode name="user">
+        <properties>
+          <helpString>User name</helpString>
+          <constraint>
+            <regex>[a-z][a-zA-Z0-9]+</regex>
+            <errorMessage>User name must start with a letter and consist of letters and digits</errorMessage>
+          </constraint>
+        </properties>
+        <children>
+          <leafNode name="full-name">
+            <properties>
+              <helpString>User full name</helpString>
+            </properties>
+          </leafNode>
+        </children>
+      </tagNode>
+      <leafNode name="hostname">
+        <properties>
+          <helpString>System hostname</helpString>
+          <valueHelpString>text</valueHelpString>
+        </properties>
       </leafNode>
-    </tagNode>
+    </children>
   </node>
 </interfaceDefinition>
diff --git a/data/schemata/interface_definition.rnc b/data/schemata/interface_definition.rnc
index a20207b..d28d06d 100644
--- a/data/schemata/interface_definition.rnc
+++ b/data/schemata/interface_definition.rnc
@@ -34,15 +34,23 @@ extendsAttr = attribute extends
     text
 }
 
-# Extends tag defines path prepended to the nodes
-extends = element extends
+# Normal and tag nodes may have children
+children = element children
 {
-    path
+    (node | tagNode | leafNode)+
 }
 
-path = attribute path
+# Nodes may have properties
+# For simplicity, any property is allowed in any node,
+# but whether they are used or not is implementation-defined
+properties = element properties
 {
-    text
+    helpString?,
+    constraint?,
+
+    # These are meaningful only for leaf nodes
+    valueHelpString?,
+    (multi | valueless)?
 }
 
 # node tag may contain node, leafNode, or tagNode tags
@@ -50,10 +58,8 @@ path = attribute path
 # other nodes and must not have values
 node = element node
 {
-    ownerAttr?,
-    nodeNameAttr,
-    helpString?,
-    (node | tagNode | leafNode)*
+    (ownerAttr? & nodeNameAttr),
+    (properties? & children? )
 }
 
 # All nodes must have "name" attribute
@@ -74,7 +80,7 @@ ownerAttr = attribute owner
 # When multiple constraints are listed, they work as logical OR
 constraint = element constraint
 {
-    (regex | validator)+,
+    (regex | validator)+ &
     errorMessage?
 }
 
@@ -87,8 +93,7 @@ regex = element regex
 # A constraint may also use an external validator
 validator = element validator
 {
-    validatorNameAttr,
-    validatorArgumentAttr,
+    (validatorNameAttr & validatorArgumentAttr),
     empty
 }
 
@@ -116,11 +121,8 @@ errorMessage = element errorMessage
 # They must not contain other tag nodes
 tagNode = element tagNode
 {
-    ownerAttr?,
-    nodeNameAttr,
-    helpString?,
-    constraint?,
-    (node | leafNode)+
+    (ownerAttr? & nodeNameAttr),
+    (properties? & children )
 }
 
 # Leaf nodes are terminal configuration nodes that can't have children,
@@ -132,10 +134,19 @@ tagNode = element tagNode
 leafNode = element leafNode
 {
     nodeNameAttr,
-    multiAttr?,
-    helpString?,
-    constraint?,
-    valueHelpString*
+    properties
+}
+
+# Some leaf nodes may have more than one value
+multi = element multi
+{
+    empty
+}
+
+# Some leaf nodes may not have values (e.g. enable/disable flags)
+valueless = element valueless
+{
+    empty
 }
 
 # helpString tag contains brief description of the purpose of the node
@@ -150,11 +161,3 @@ valueHelpString = element valueHelpString
 {
     text
 }
-
-# multi=<true|false> attribute indicates that a leaf node can have
-# multiple values
-# If not present, treated as "false"
-multiAttr = attribute multi
-{
-    xsd:boolean
-}
diff --git a/data/schemata/interface_definition.rng b/data/schemata/interface_definition.rng
index 7a53182..bc55542 100644
--- a/data/schemata/interface_definition.rng
+++ b/data/schemata/interface_definition.rng
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<grammar xmlns="http://relaxng.org/ns/structure/1.0" datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
+<grammar xmlns="http://relaxng.org/ns/structure/1.0">
   <!--
        interface_definition.rnc: VyConf reference tree XML grammar
     
@@ -25,55 +25,82 @@
     http://relaxng.org/compact-tutorial-20030326.htm
     (unless converted to XML, then just RELAX-NG :)
   -->
-  <!--
-    Interface definition starts with interfaceDefinition tag that may contain node tags
-    It also may contain "extends" tags, if nodes must be appended to certain path
-  -->
+  <!-- Interface definition starts with interfaceDefinition tag that may contain node tags -->
   <start>
     <element name="interfaceDefinition">
-      <zeroOrMore>
-        <ref name="extends"/>
-      </zeroOrMore>
-      <ref name="nodeList"/>
-    </element>
-  </start>
-  <define name="nodeList">
-    <element name="nodeList">
+      <optional>
+        <ref name="extendsAttr"/>
+      </optional>
       <zeroOrMore>
         <ref name="node"/>
       </zeroOrMore>
     </element>
+  </start>
+  <!--
+    Interface definitions may extend other definitions
+    In this case you specify a whitespace-separated path
+  -->
+  <define name="extendsAttr">
+    <attribute name="extends"/>
   </define>
-  <!-- Extends tag defines path prepended to the nodes -->
-  <define name="extends">
-    <element name="extends">
-      <ref name="path"/>
+  <!-- Normal and tag nodes may have children -->
+  <define name="children">
+    <element name="children">
+      <oneOrMore>
+        <choice>
+          <ref name="node"/>
+          <ref name="tagNode"/>
+          <ref name="leafNode"/>
+        </choice>
+      </oneOrMore>
     </element>
   </define>
-  <define name="path">
-    <attribute name="path"/>
-  </define>
   <!--
-    node tag may contain node, leafNode, or tagNode tags
-    Those are intermediate configuration nodes that may only contain
-    other nodes and must not have values
+    Nodes may have properties
+    For simplicity, any property is allowed in any node,
+    but whether they are used or not is implementation-defined
   -->
-  <define name="node">
-    <element name="node">
+  <define name="properties">
+    <element name="properties">
       <optional>
-        <ref name="ownerAttr"/>
+        <ref name="helpString"/>
       </optional>
-      <ref name="nodeNameAttr"/>
       <optional>
-        <ref name="helpString"/>
+        <ref name="constraint"/>
       </optional>
-      <zeroOrMore>
+      <optional>
+        <!-- These are meaningful only for leaf nodes -->
+        <ref name="valueHelpString"/>
+      </optional>
+      <optional>
         <choice>
-          <ref name="node"/>
-          <ref name="tagNode"/>
-          <ref name="leafNode"/>
+          <ref name="multi"/>
+          <ref name="valueless"/>
         </choice>
-      </zeroOrMore>
+      </optional>
+    </element>
+  </define>
+  <!--
+    node tag may contain node, leafNode, or tagNode tags
+    Those are intermediate configuration nodes that may only contain
+    other nodes and must not have values
+  -->
+  <define name="node">
+    <element name="node">
+      <interleave>
+        <optional>
+          <ref name="ownerAttr"/>
+        </optional>
+        <ref name="nodeNameAttr"/>
+      </interleave>
+      <interleave>
+        <optional>
+          <ref name="properties"/>
+        </optional>
+        <optional>
+          <ref name="children"/>
+        </optional>
+      </interleave>
     </element>
   </define>
   <!-- All nodes must have "name" attribute -->
@@ -94,15 +121,17 @@
   -->
   <define name="constraint">
     <element name="constraint">
-      <oneOrMore>
-        <choice>
-          <ref name="regex"/>
-          <ref name="validator"/>
-        </choice>
-      </oneOrMore>
-      <optional>
-        <ref name="errorMessage"/>
-      </optional>
+      <interleave>
+        <oneOrMore>
+          <choice>
+            <ref name="regex"/>
+            <ref name="validator"/>
+          </choice>
+        </oneOrMore>
+        <optional>
+          <ref name="errorMessage"/>
+        </optional>
+      </interleave>
     </element>
   </define>
   <!-- A constraint may be a regex pattern -->
@@ -114,8 +143,10 @@
   <!-- A constraint may also use an external validator -->
   <define name="validator">
     <element name="validator">
-      <ref name="validatorNameAttr"/>
-      <ref name="validatorArgumentAttr"/>
+      <interleave>
+        <ref name="validatorNameAttr"/>
+        <ref name="validatorArgumentAttr"/>
+      </interleave>
       <empty/>
     </element>
   </define>
@@ -141,22 +172,18 @@
   -->
   <define name="tagNode">
     <element name="tagNode">
-      <optional>
-        <ref name="ownerAttr"/>
-      </optional>
-      <ref name="nodeNameAttr"/>
-      <optional>
-        <ref name="helpString"/>
-      </optional>
-      <optional>
-        <ref name="constraint"/>
-      </optional>
-      <oneOrMore>
-        <choice>
-          <ref name="node"/>
-          <ref name="leafNode"/>
-        </choice>
-      </oneOrMore>
+      <interleave>
+        <optional>
+          <ref name="ownerAttr"/>
+        </optional>
+        <ref name="nodeNameAttr"/>
+      </interleave>
+      <interleave>
+        <optional>
+          <ref name="properties"/>
+        </optional>
+        <ref name="children"/>
+      </interleave>
     </element>
   </define>
   <!--
@@ -170,18 +197,19 @@
   <define name="leafNode">
     <element name="leafNode">
       <ref name="nodeNameAttr"/>
-      <optional>
-        <ref name="multiAttr"/>
-      </optional>
-      <optional>
-        <ref name="helpString"/>
-      </optional>
-      <optional>
-        <ref name="constraint"/>
-      </optional>
-      <zeroOrMore>
-        <ref name="valueHelpString"/>
-      </zeroOrMore>
+      <ref name="properties"/>
+    </element>
+  </define>
+  <!-- Some leaf nodes may have more than one value -->
+  <define name="multi">
+    <element name="multi">
+      <empty/>
+    </element>
+  </define>
+  <!-- Some leaf nodes may not have values (e.g. enable/disable flags) -->
+  <define name="valueless">
+    <element name="valueless">
+      <empty/>
     </element>
   </define>
   <!--
@@ -199,14 +227,4 @@
       <text/>
     </element>
   </define>
-  <!--
-    multi=<true|false> attribute indicates that a leaf node can have
-    multiple values
-    If not present, treated as "false"
-  -->
-  <define name="multiAttr">
-    <attribute name="multi">
-      <data type="boolean"/>
-    </attribute>
-  </define>
 </grammar>