Golang xml不会解组

Question

Im trying to unmarshal the following code that has the go playground at the bottom. The data.DocumentType always returns 0 and should return the inner xml 4. Can someone tell me why this doesnt work?

package main

import (
    "encoding/xml"
    "fmt"

)

type doc struct {
    XMLName       xml.Name `xml:"ownershipDocument"`
    SchemaVersion string   `xml:",innerxml"`
    DocumentType  int      `xml:",innerxml"`
}

func main() {
    var Data doc
    xml.Unmarshal([]byte(VV), &Data)
    fmt.Println(Data.DocumentType)

}

const VV = `<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-11-18</periodOfReport>

    <issuer>
        <issuerCik>0000820081</issuerCik>
        <issuerName>CAMBREX CORP</issuerName>
        <issuerTradingSymbol>CBM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001227832</rptOwnerCik>
            <rptOwnerName>KORB WILLIAM B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1 MEADOWLANDS PLAZA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>EAST RUTHERFORD</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07073</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>50.18</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36562</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $50.00 to $50.58 inclusive. The reporting person undertakes to provide to Cambrex Corporation, any security holder of Cambrex Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this Footnote 1 to this Form 4.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Samantha Hanley for William B. Korb by POA</signatureName>
        <signatureDate>2015-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>`

http://play.golang.org/p/nJbAF0zKSJ

Answer 1

Remove the innerxml tag on DocumentType, and give it the name of the element to to match (xml:"documentType"). From the xml library docs:

If the struct has a field of type []byte or string with tag ",innerxml", Unmarshal accumulates the raw XML nested inside the element in that field. The rest of the rules still apply.

You don't need to store unprocessed XML. You're looking for the value of the field, so you don't need the tag.

Working version

*edit: For that matter, the ",innerxml" tag will also break the SchemaVersion field as well—without a matching element (and since SchemaVersion is a string), it stores the whole document.