Avoid XML integer parse errors if field empty

Consider these 2 XML documents

<a>
  <b nil="true"></b>
</a>

and

<a>
  <b type="integer">1</b>
</a>

How can I unmarshal this XML properly in Go to a b struct field of type int, without producing a strconv.ParseInt: parsing "": invalid syntax error in the first case?

omitempty doesn't seem to work in this case.

Example: http://play.golang.org/p/fbhVJ4zUbl

The omitempty tag is just respected with Marshal, not Unmarshal.

Unmarshal errors if the int value is not an actual int.

Instead, change B to a string. Then, convert B to an int with the strconv package. If it errors, set it to 0.

Try this snippet: http://play.golang.org/p/1zqmlmIQDB

You can use "github.com/guregu/null" package. It helps:

package main
import (
"fmt"
	"encoding/xml"
	"github.com/guregu/null"
)

type Items struct{
	It []Item `xml:"Item"`
}

type Item struct {
	DealNo   string
	ItemNo   null.Int
	Name     string
	Price    null.Float
	Quantity null.Float
	Place    string
}

func main(){
	data := `
	<Items>
		<Item>
	            <DealNo/>
	            <ItemNo>32435</ItemNo>
	            <Name>dsffdf</Name>
	            <Price>135.12</Price>
	            <Quantity></Quantity>
	            <Place>dsffs</Place>
	        </Item>
	        <Item>
	            <DealNo/>
	            <ItemNo></ItemNo>
	            <Name>dsfsfs</Name>
	            <Price></Price>
	            <Quantity>1.5</Quantity>
	            <Place>sfsfsfs</Place>
	        </Item>
			</Items>`

var xmlMsg Items

        if err := xml.Unmarshal([]byte(data), &xmlMsg); err != nil {
		fmt.Println("Error: cannot unmarshal xml from web ", err)
		} else {
			fmt.Println("XML: ", xmlMsg)
		}
}