yq/pkg/yqlib/decoder_xml.go

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package yqlib
import (
"encoding/xml"
"errors"
"fmt"
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"io"
"strings"
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"unicode"
"golang.org/x/net/html/charset"
yaml "gopkg.in/yaml.v3"
)
type xmlDecoder struct {
reader io.Reader
readAnything bool
finished bool
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prefs XmlPreferences
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}
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func NewXMLDecoder(prefs XmlPreferences) Decoder {
return &xmlDecoder{
finished: false,
prefs: prefs,
}
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}
func (dec *xmlDecoder) Init(reader io.Reader) error {
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dec.reader = reader
dec.readAnything = false
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dec.finished = false
return nil
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}
func (dec *xmlDecoder) createSequence(nodes []*xmlNode) (*yaml.Node, error) {
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yamlNode := &yaml.Node{Kind: yaml.SequenceNode, Tag: "!!seq"}
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for _, child := range nodes {
yamlChild, err := dec.convertToYamlNode(child)
if err != nil {
return nil, err
}
yamlNode.Content = append(yamlNode.Content, yamlChild)
}
return yamlNode, nil
}
func (dec *xmlDecoder) processComment(c string) string {
if c == "" {
return ""
}
return "#" + strings.TrimRight(c, " ")
}
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func (dec *xmlDecoder) createMap(n *xmlNode) (*yaml.Node, error) {
log.Debug("createMap: headC: %v, lineC: %v, footC: %v", n.HeadComment, n.LineComment, n.FootComment)
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yamlNode := &yaml.Node{Kind: yaml.MappingNode, Tag: "!!map"}
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if len(n.Data) > 0 {
log.Debugf("creating content node for map: %v", dec.prefs.ContentName)
label := dec.prefs.ContentName
labelNode := createScalarNode(label, label)
labelNode.HeadComment = dec.processComment(n.HeadComment)
labelNode.LineComment = dec.processComment(n.LineComment)
labelNode.FootComment = dec.processComment(n.FootComment)
yamlNode.Content = append(yamlNode.Content, labelNode, dec.createValueNodeFromData(n.Data))
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}
for i, keyValuePair := range n.Children {
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label := keyValuePair.K
children := keyValuePair.V
labelNode := createScalarNode(label, label)
var valueNode *yaml.Node
var err error
if i == 0 {
labelNode.HeadComment = dec.processComment(n.HeadComment)
}
log.Debugf("label=%v, i=%v, keyValuePair.FootComment: %v", label, i, keyValuePair.FootComment)
labelNode.FootComment = dec.processComment(keyValuePair.FootComment)
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log.Debug("len of children in %v is %v", label, len(children))
if len(children) > 1 {
valueNode, err = dec.createSequence(children)
if err != nil {
return nil, err
}
} else {
// comment hack for maps of scalars
// if the value is a scalar, the head comment of the scalar needs to go on the key?
// add tests for <z/> as well as multiple <ds> of inputXmlWithComments > yaml
if len(children[0].Children) == 0 && children[0].HeadComment != "" {
if len(children[0].Data) > 0 {
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log.Debug("scalar comment hack, currentlabel [%v]", labelNode.HeadComment)
labelNode.HeadComment = joinComments([]string{labelNode.HeadComment, strings.TrimSpace(children[0].HeadComment)}, "\n")
children[0].HeadComment = ""
} else {
// child is null, put the headComment as a linecomment for reasons
children[0].LineComment = children[0].HeadComment
children[0].HeadComment = ""
}
}
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valueNode, err = dec.convertToYamlNode(children[0])
if err != nil {
return nil, err
}
}
yamlNode.Content = append(yamlNode.Content, labelNode, valueNode)
}
return yamlNode, nil
}
func (dec *xmlDecoder) createValueNodeFromData(values []string) *yaml.Node {
switch len(values) {
case 0:
return createScalarNode(nil, "")
case 1:
return createScalarNode(values[0], values[0])
default:
content := make([]*yaml.Node, 0)
for _, value := range values {
content = append(content, createScalarNode(value, value))
}
return &yaml.Node{
Kind: yaml.SequenceNode,
Tag: "!!seq",
Content: content,
}
}
}
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func (dec *xmlDecoder) convertToYamlNode(n *xmlNode) (*yaml.Node, error) {
if len(n.Children) > 0 {
return dec.createMap(n)
}
scalar := dec.createValueNodeFromData(n.Data)
log.Debug("scalar (%v), headC: %v, lineC: %v, footC: %v", scalar.Tag, n.HeadComment, n.LineComment, n.FootComment)
scalar.HeadComment = dec.processComment(n.HeadComment)
scalar.LineComment = dec.processComment(n.LineComment)
if scalar.Tag == "!!seq" {
scalar.Content[0].HeadComment = scalar.LineComment
scalar.LineComment = ""
}
scalar.FootComment = dec.processComment(n.FootComment)
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return scalar, nil
}
func (dec *xmlDecoder) Decode() (*CandidateNode, error) {
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if dec.finished {
return nil, io.EOF
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}
root := &xmlNode{}
// cant use xj - it doesn't keep map order.
err := dec.decodeXML(root)
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if err != nil {
return nil, err
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}
firstNode, err := dec.convertToYamlNode(root)
if err != nil {
return nil, err
} else if firstNode.Tag == "!!null" {
dec.finished = true
if dec.readAnything {
return nil, io.EOF
}
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}
dec.readAnything = true
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dec.finished = true
return &CandidateNode{
Node: &yaml.Node{
Kind: yaml.DocumentNode,
Content: []*yaml.Node{firstNode},
},
}, nil
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}
type xmlNode struct {
Children []*xmlChildrenKv
HeadComment string
FootComment string
LineComment string
Data []string
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}
type xmlChildrenKv struct {
K string
V []*xmlNode
FootComment string
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}
// AddChild appends a node to the list of children
func (n *xmlNode) AddChild(s string, c *xmlNode) {
if n.Children == nil {
n.Children = make([]*xmlChildrenKv, 0)
}
log.Debug("looking for %s", s)
// see if we can find an existing entry to add to
for _, childEntry := range n.Children {
if childEntry.K == s {
log.Debug("found it, appending an entry%s", s)
childEntry.V = append(childEntry.V, c)
log.Debug("yay len of children in %v is %v", s, len(childEntry.V))
return
}
}
log.Debug("not there, making a new one %s", s)
n.Children = append(n.Children, &xmlChildrenKv{K: s, V: []*xmlNode{c}})
}
type element struct {
parent *element
n *xmlNode
label string
state string
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}
// this code is heavily based on https://github.com/basgys/goxml2json
// main changes are to decode into a structure that preserves the original order
// of the map keys.
func (dec *xmlDecoder) decodeXML(root *xmlNode) error {
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xmlDec := xml.NewDecoder(dec.reader)
xmlDec.Strict = dec.prefs.StrictMode
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// That will convert the charset if the provided XML is non-UTF-8
xmlDec.CharsetReader = charset.NewReaderLabel
started := false
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// Create first element from the root node
elem := &element{
parent: nil,
n: root,
}
getToken := func() (xml.Token, error) {
if dec.prefs.UseRawToken {
return xmlDec.RawToken()
}
return xmlDec.Token()
}
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for {
t, e := getToken()
if e != nil && !errors.Is(e, io.EOF) {
return e
}
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if t == nil {
break
}
switch se := t.(type) {
case xml.StartElement:
log.Debug("start element %v", se.Name.Local)
elem.state = "started"
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// Build new a new current element and link it to its parent
elem = &element{
parent: elem,
n: &xmlNode{},
label: se.Name.Local,
}
// Extract attributes as children
for _, a := range se.Attr {
if dec.prefs.KeepNamespace {
if a.Name.Space != "" {
a.Name.Local = a.Name.Space + ":" + a.Name.Local
}
}
elem.n.AddChild(dec.prefs.AttributePrefix+a.Name.Local, &xmlNode{Data: []string{a.Value}})
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}
case xml.CharData:
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// Extract XML data (if any)
newBit := trimNonGraphic(string(se))
if !started && len(newBit) > 0 {
return fmt.Errorf("invalid XML: Encountered chardata [%v] outside of XML node", newBit)
}
if len(newBit) > 0 {
elem.n.Data = append(elem.n.Data, newBit)
elem.state = "chardata"
log.Debug("chardata [%v] for %v", elem.n.Data, elem.label)
}
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case xml.EndElement:
log.Debug("end element %v", elem.label)
elem.state = "finished"
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// And add it to its parent list
if elem.parent != nil {
elem.parent.n.AddChild(elem.label, elem.n)
}
// Then change the current element to its parent
elem = elem.parent
case xml.Comment:
commentStr := string(xml.CharData(se))
if elem.state == "started" {
applyFootComment(elem, commentStr)
} else if elem.state == "chardata" {
log.Debug("got a line comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
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elem.n.LineComment = joinComments([]string{elem.n.LineComment, commentStr}, " ")
} else {
log.Debug("got a head comment for (%v) %v: [%v]", elem.state, elem.label, commentStr)
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elem.n.HeadComment = joinComments([]string{elem.n.HeadComment, commentStr}, " ")
}
case xml.ProcInst:
if !dec.prefs.SkipProcInst {
elem.n.AddChild(dec.prefs.ProcInstPrefix+se.Target, &xmlNode{Data: []string{string(se.Inst)}})
}
case xml.Directive:
if !dec.prefs.SkipDirectives {
elem.n.AddChild(dec.prefs.DirectiveName, &xmlNode{Data: []string{string(se)}})
}
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}
started = true
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}
return nil
}
func applyFootComment(elem *element, commentStr string) {
// first lets try to put the comment on the last child
if len(elem.n.Children) > 0 {
lastChildIndex := len(elem.n.Children) - 1
childKv := elem.n.Children[lastChildIndex]
log.Debug("got a foot comment, putting on last child for %v: [%v]", childKv.K, commentStr)
// if it's an array of scalars, put the foot comment on the scalar itself
if len(childKv.V) > 0 && len(childKv.V[0].Children) == 0 {
nodeToUpdate := childKv.V[len(childKv.V)-1]
nodeToUpdate.FootComment = joinComments([]string{nodeToUpdate.FootComment, commentStr}, " ")
} else {
childKv.FootComment = joinComments([]string{elem.n.FootComment, commentStr}, " ")
}
} else {
log.Debug("got a foot comment for %v: [%v]", elem.label, commentStr)
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elem.n.FootComment = joinComments([]string{elem.n.FootComment, commentStr}, " ")
}
}
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func joinComments(rawStrings []string, joinStr string) string {
stringsToJoin := make([]string, 0)
for _, str := range rawStrings {
if str != "" {
stringsToJoin = append(stringsToJoin, str)
}
}
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return strings.Join(stringsToJoin, joinStr)
}
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// trimNonGraphic returns a slice of the string s, with all leading and trailing
// non graphic characters and spaces removed.
//
// Graphic characters include letters, marks, numbers, punctuation, symbols,
// and spaces, from categories L, M, N, P, S, Zs.
// Spacing characters are set by category Z and property Pattern_White_Space.
func trimNonGraphic(s string) string {
if s == "" {
return s
}
var first *int
var last int
for i, r := range []rune(s) {
if !unicode.IsGraphic(r) || unicode.IsSpace(r) {
continue
}
if first == nil {
f := i // copy i
first = &f
last = i
} else {
last = i
}
}
// If first is nil, it means there are no graphic characters
if first == nil {
return ""
}
return string([]rune(s)[*first : last+1])
}