Changes between Initial Version and Version 1 of FAQ_XmlPathNames

Timestamp:

Mar 8, 2006 8:39:14 PM (18 years ago)

Author:

dkearney

Comment:

--

FAQ_XmlPathNames

@@ +1 @@
+= How do I read XML Paths with Rappture1.x? =
+
+Rappture uses a very simple, clear method for refering to elements
+of an xml tree. Take this node for example:
+
+{{{
+<run>
+    <input>
+        <number id="temperature">
+            <default>10</default>
+            <current>15</current>
+        </number>
+    </input>
+</run>
+}}}
+
+In the above example, there are 4 accessible xml nodes.
+  1. input
+  2. number
+  3. default
+  4. current
+
+<run> is not considered an accessible node for Rappture.
+Instead it is named the root node. All xml information
+relevant to Rappture can be found inside of the root node's 
+<run>...</run> tags.
+
+In general all accessible nodes are named using the following scheme:
+{{{
+nodeType(nodeId)
+}}} 
+
+nodeType refers to the type of node, or the text found between '<' and '>'.
+nodeId refers to the id attribute within the opening node tag.
+In the first example, the different nodeTypes are input, number, default, 
+and current. Only one node has a nodeId, that is the number node. Since the
+input tag has no nodeId, its xml path (relative to the root node) is:
+
+{{{
+input
+}}}
+
+In the first example the number node can be referred to using three 
+different names
+
+{{{
+input.number
+input.number(temperature)
+input.(temperature)
+}}}
+
+The first way of referring to the number node simply joins two node names 
+together. The second way reflects a stricter naming convention which
+encompasses full names for all nodes. The full name for the input nodes is
+'input' and the full name for the number node is 'number(temperature)'.
+The third name is a bit trickier to decompose. 'input' is the nodeType of the
+parent node, but the nodeType of the child node is not provided. This is
+acceptable. As a short cut, if the nodeId is provided within parenthesis,
+it can still be searched for.
+
+Note that the best way to refer to a node is to use its full name. There
+would be no guarantee the correct node will be found if without using 
+the full name if the xml looked like this:
+{{{
+<run>
+    <input>
+        <number id="temperature">
+            <default>10</default>
+            <current>15</current>
+        </number>
+        <number id="Ef">
+            <default>3</default>
+            <current>2</current>
+        </number>
+
+    </input>
+</run>
+}}}
+
+In this case, just saying 'input.number' would return the first instance 
+of the node of type 'number' under the parent node 'input'. A more appropriate
+way of referring to each of these nodes would be:
+
+{{{
+input.number(temperature)
+input.number(Ef)
+}}}
+
+Similarly the default and current tags can be referred to using the following names:
+{{{
+input.number(temperature).default
+input.number(temperature).current
+}}}
+
+[wiki:FAQ Back to Frequently Asked Questions]