go_conf/schema.go

132 lines
2.9 KiB
Go
Raw Normal View History

2020-09-12 01:25:44 -04:00
package conf
// The usage of this depends on the successful resolution of https://github.com/lestrrat-go/libxml2/issues/67.
import (
`errors`
`io/ioutil`
`net/http`
`regexp`
`strings`
lxml `github.com/lestrrat-go/libxml2`
lxmlp `github.com/lestrrat-go/libxml2/parser`
lxmlt `github.com/lestrrat-go/libxml2/types`
`github.com/lestrrat-go/libxml2/xsd`
rpaths `r00t2.io/sysutils/paths`
)
var uriRe = regexp.MustCompile(`^(?P<type>file|https?)://(?P<path>.+)$`)
type NSXML struct {
XML *[]byte // The raw XML bytes.
LXML lxmlt.Document // The lxml.Parse()'d XML.
Root lxmlt.Element // The Document's root element
XSD xsd.Schema // Its schema.
}
func (x *NSXML) Validate(defaults bool) (bool, error) {
// We need the XSD before we can validate.
if err := x.getXSD(); err != nil {
return false, err
}
return false, nil
}
func (x *NSXML) getXSD() error {
if err := x.mapNS(); err != nil {
return err
}
r := uriRe.FindStringSubmatch(strings.ToLower(x.XSDPath))
reResults := make(map[string]string)
for i, name := range uriRe.SubexpNames() {
if i != 0 && name != "" {
reResults[name] = r[i]
}
}
var xsdRaw []byte
switch reResults["type"] {
case "file":
p := reResults["path"]
exists, err := rpaths.RealPathExists(&p)
if (err != nil) || (!exists) {
return err
}
xsdRaw, err = ioutil.ReadFile(p)
if err != nil {
return err
}
case "http", "https":
resp, err := http.Get(x.XSDPath)
if err != nil {
return err
}
defer resp.Body.Close()
xsdRaw, err = ioutil.ReadAll(resp.Body)
if err != nil {
return err
}
default:
return errors.New("invalid URI type for schemaLocation")
}
x.XSD, err = xsd.Parse(xsdRaw)
if err != nil {
return err
}
}
// mapNS (tries to) extract the default namespace from the document via the SchemaLocation property of XML, sets DefaultNS,
// and then gets the XSDPath specified therein.
func (x *NSXML) mapNS() error {
if x.XSD.Pointer() != 0 {
// Already set.
return nil
}
if err := x.parse(); err != nil {
return err
}
x.DefaultNS = x.Root.NamespaceURI()
/* x.DefaultNS = *x.XML.XMLName.Space
sl := *x.XML.SchemaLocation
*/
ns := strings.Fields(sl)
if ns != nil {
if len(ns) > 2 {
return errors.New("too many values for a valid schemaLocation")
} else if len(ns) == 0 {
return errors.New("no specified value for schemaLocation")
} else if len(ns) == 1 {
// LAZY. This is improper XML, but is commonly used regardless.
x.XSDPath = ns[0]
} else {
if ns[0] == x.DefaultNS {
x.XSDPath = ns[1]
}
}
}
return nil
}
// parse parses the x.XML into its x.LXML
func (x *NSXML) parse() error {
if x.LXML != nil {
return nil // Already parsed
}
if x.XML == nil {
return errors.New("XML property is empty")
}
x.LXML, err = lxml.Parse(*x.XML, lxmlp.XMLParseBigLines, lxmlp.XMLParseXInclude)
if err != nil {
return err
}
de, err := x.LXML.DocumentElement()
if err != nil {
return err
}
x.Root = de.(lxmlt.Element)
return nil
}