Solved: Converting a variable into JSON to XML in APIGEE - Page 2

Report Inappropriate Content · 03-21-2016 02:18 PM

I want to convert a JSON header variable into XML variable.And then later insert that XML variable into another XML message sent as request to a service provider.

But I am facing issues while doing so.

The approach I am trying is,

1)I am saving a header variable which is in json format into some other variable.

2)And referring that variable in JSON to XML conversion.

<Source>In_JSON_Var</Source> <OutputVariable>Out_XML_Var</OutputVariable>

Here XML is getting appended with XML version tag.

<?xml version="1.0" encoding="UTF-8"?><Fruit>Orange</Fruit>

3)I am inserting an XSLT after this to remove the root XML element.But XSLT fails with below reason

"java.lang.String cannot be cast to com.apigee.flow.message.Message"

   <Source>Out_XML_Var</Source>
    <ResourceURL>xsl://RemoteXMLRoot.xsl</ResourceURL>
    <Parameters ignoreUnresolvedVariables="true"/>
    <OutputVariable>Out_XML_Var_NoRoot</OutputVariable>

Please help me with anyother better approach.

DChiesa

Yes, the source of the problem here is that the XSL Policy in Apigee Edge always takes a Message as input. A string is not suitable. Your Out_XML_Var is a string, not a message.

You can use an AssignMessage policy to wrap a message around a string, like this:

<AssignMessage name='AM-temp'>
  <DisplayName>AM-temp</DisplayName>
  <Description>wrap a message around a string</Description>
  <AssignTo createNew='true' transport='http' type='request'>wrapped</AssignTo>
  <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
  <Set>
    <Payload contentType='application/xml'
             variablePrefix='%' variableSuffix='#'>%Out_XML_Var#</Payload>
    <StatusCode>200</StatusCode>
    <ReasonPhrase>OK</ReasonPhrase>
  </Set>
</AssignMessage>

...and this will then be suitable for use as input to an XSL policy.

You can then "remove" the Root element. But keep in mind, in the general case, you need a root element. What I mean is, this json:

{
  "name1" : "Value1",
  "name2" : "Value2"
}

...when passed through the XMLToJSON policy, gets converted into this XML:

<Root>
  <name1>Value1</name1>
  <name2>Value2</name2>
</Root>

But simply "removing" the root produces a non-well-formed XML document. In other words, this is not a well-formed document:

  <name1>Value1</name1>
  <name2>Value2</name2>

But in the case that your JSON has a single element, then "removing" the root element will result in a valid XML document.

One more suggestion: you're editing bits of XML. This custom policy may be helpful:

https://github.com/DinoChiesa/ApigeeEdge-Java-Add-Xml-Node

It can remove nodes in an XML doc (including nodes that are elements), insert nodes (including elements), or replace nodes (including elements) . And there's no need to write XSLT, though you do have to write an XPath!

View solution in original post