dynamic xml

[Jeffrey Smith]

I have a lot of XML documents that have sections in that contain tags that can be of any name but will contain type,minOccurs,maxOccurs and have a description inside it. For instance name,description,definition and id below.

<?xml version="1.0" encoding="utf-8"?>
<topLevel name="insight">
  <description>description number1</description>
  <rights>
    <privLevel>user</privLevel>
  </rights>
  <method name="graphCreate">
    <description>graphCreate API</description>
    <rights></rights>
    <request>
      <params>
        <name type="xs:string" minOccurs="1" >
          <description>A friendly name to identify the graph</description>
        </name>
        <description type="xs:string" minOccurs="1" >
          <description>Detailed description of the graph</description>
        </description>        
        <definition type="graphDefinition" minOccurs="1" maxOccurs="1">
          <description>Specify the graph definition. i.e how this graph should be built.</description>
        </definition>
      </params>
    </request>
    <response>
      <params>
   <id type="xs:unsignedInt" minOccurs="1" >
          <description>graph identifier.</description>
        </id>
      </params>
    </response>
  </method>
 </topLevel>

Whats the best way to parse this. So far I have but can't work out how to dynamically generate the struct to stuff this into. Any suggestions?

type topLevel struct {
        Description string   `xml:"description"`
        Rights      rights   `xml:"rights"`
        Method      []method `xml:"method"`
}


type method struct {
        Name        string  `xml:"name,attr"`
        Description string  `xml:"description"`
        Rights      []right `xml:"rights"`
}


type right struct {
        Right string `xml:"right"`
}


type request struct {
}


type rights struct {
        PrivLevel string `xml:"privLevel"`
}

[Jim Cote]

You'll need to use an UnmarshalXML func for the params:

// Param is a tag w/ any name
type Param struct {
    Name        string `xml:"-"`
    Type        string `xml:"type,attr"`
    MinOccurs   int    `xml:"minOccurs,attr"`
    MaxOccurs   int    `xml:"maxOccurs,attr"`
    Description string `xml:"description"`
}


// ParamList type for unmarhsal
type ParamList []Param


// UnmarshalXML for the win
func (pl *ParamList) UnmarshalXML(d *xml.Decoder, s xml.StartElement) error {
    tk, err := d.Token()
    for err == nil {
        switch t := tk.(type) {
        case xml.StartElement:
            param := Param{Name: t.Name.Local}
            if err = d.DecodeElement(&param, &t); err != nil {
                return err
            }
            *pl = append(*pl, param)
         }
         if tk, err = d.Token(); err == io.EOF {
             return nil
         }
    }
    return err
}


// TopLevel is of course top level
type TopLevel struct {
    Description string   `xml:"description"`
    Rights      Rights   `xml:"rights"`
    Method      []Method `xml:"method"`
}


// Method has request
type Method struct {

    Name        string   `xml:"name,attr"`
    Description string   `xml:"description"`

    Rights      []Right  `xml:"rights"`
    Request     Request  `xml:"request"`
    Response    Response `xml:"response"`
}


// Right whatever
type Right struct {
    Right string `xml:"right"`
}


// Request like Response
type Request struct {
    Params ParamList `xml:"params"`
}


// Response like Request
type Response struct {
    Params ParamList `xml:"params"`
}


// Rights
type Rights struct {
    PrivLevel string `xml:"privLevel"`
}