From c1b333b2c25f45b9265cf229611b2253fb424b35 Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Tue, 18 Oct 2022 14:15:25 +1100
Subject: [PATCH] Added xml support for proc instructions

---
 examples/mike.xml        | 20 ++++++--------------
 pkg/yqlib/decoder_xml.go |  8 ++++++--
 pkg/yqlib/encoder_xml.go | 38 +++++++++++++++++++++++++++++---------
 3 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/examples/mike.xml b/examples/mike.xml
index 94773b86..75a65193 100644
--- a/examples/mike.xml
+++ b/examples/mike.xml
@@ -1,14 +1,6 @@
-<!-- before cat -->
-<cat>
-	<!-- in cat before -->
-	<x>3<!-- multi
-line comment
-for x --></x>
-	<y>
-		<!-- in y before -->
-		<d><!-- in d before -->4<!-- in d after --></d>
-		<!-- in y after -->
-	</y>
-	<!-- in_cat_after -->
-</cat>
-<!-- after cat -->
\ No newline at end of file
+<?xml version="1.0"?>
+<!DOCTYPE config SYSTEM "/etc/iwatch/iwatch.dtd" >
+<apple>
+Cats are cgreat
+<b>things</b>
+</apple>
\ No newline at end of file
diff --git a/pkg/yqlib/decoder_xml.go b/pkg/yqlib/decoder_xml.go
index d053f6ca..7ff1bcee 100644
--- a/pkg/yqlib/decoder_xml.go
+++ b/pkg/yqlib/decoder_xml.go
@@ -15,6 +15,8 @@ type xmlDecoder struct {
 	reader          io.Reader
 	readAnything    bool
 	attributePrefix string
+	directivePrefix string
+	procInstPrefix  string
 	contentName     string
 	strictMode      bool
 	keepNamespace   bool
@@ -33,6 +35,8 @@ func NewXMLDecoder(attributePrefix string, contentName string, strictMode bool,
 		strictMode:      strictMode,
 		keepNamespace:   keepNamespace,
 		useRawToken:     useRawToken,
+		directivePrefix: "_directive_",
+		procInstPrefix:  "_procInst_",
 	}
 }
 
@@ -86,9 +90,7 @@ func (dec *xmlDecoder) createMap(n *xmlNode) (*yaml.Node, error) {
 
 		}
 
-		// if i == len(n.Children)-1 {
 		labelNode.FootComment = dec.processComment(keyValuePair.FootComment)
-		// }
 
 		log.Debug("len of children in %v is %v", label, len(children))
 		if len(children) > 1 {
@@ -282,6 +284,8 @@ func (dec *xmlDecoder) decodeXML(root *xmlNode) error {
 				elem.n.HeadComment = joinFilter([]string{elem.n.HeadComment, commentStr})
 			}
 
+		case xml.ProcInst:
+			elem.n.AddChild(dec.procInstPrefix+se.Target, &xmlNode{Data: string(se.Inst)})
 		}
 	}
 
diff --git a/pkg/yqlib/encoder_xml.go b/pkg/yqlib/encoder_xml.go
index b84b59de..39cf1bfc 100644
--- a/pkg/yqlib/encoder_xml.go
+++ b/pkg/yqlib/encoder_xml.go
@@ -15,6 +15,8 @@ type xmlEncoder struct {
 	attributePrefix string
 	contentName     string
 	indentString    string
+	directivePrefix string
+	procInstPrefix  string
 }
 
 func NewXMLEncoder(indent int, attributePrefix string, contentName string) Encoder {
@@ -23,7 +25,7 @@ func NewXMLEncoder(indent int, attributePrefix string, contentName string) Encod
 	for index := 0; index < indent; index++ {
 		indentString = indentString + " "
 	}
-	return &xmlEncoder{attributePrefix, contentName, indentString}
+	return &xmlEncoder{attributePrefix, contentName, indentString, "_directive_", "_procInst_"}
 }
 
 func (e *xmlEncoder) CanHandleAliases() bool {
@@ -44,7 +46,7 @@ func (e *xmlEncoder) Encode(writer io.Writer, node *yaml.Node) error {
 
 	switch node.Kind {
 	case yaml.MappingNode:
-		err := e.encodeTopLevelMap(encoder, node)
+		err := e.encodeTopLevelMap(encoder, node, writer)
 		if err != nil {
 			return err
 		}
@@ -53,7 +55,7 @@ func (e *xmlEncoder) Encode(writer io.Writer, node *yaml.Node) error {
 		if err != nil {
 			return err
 		}
-		err = e.encodeTopLevelMap(encoder, unwrapDoc(node))
+		err = e.encodeTopLevelMap(encoder, unwrapDoc(node), writer)
 		if err != nil {
 			return err
 		}
@@ -76,7 +78,7 @@ func (e *xmlEncoder) Encode(writer io.Writer, node *yaml.Node) error {
 
 }
 
-func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *yaml.Node) error {
+func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *yaml.Node, writer io.Writer) error {
 	err := e.encodeComment(encoder, headAndLineComment(node))
 	if err != nil {
 		return err
@@ -92,11 +94,23 @@ func (e *xmlEncoder) encodeTopLevelMap(encoder *xml.Encoder, node *yaml.Node) er
 			return err
 		}
 
-		log.Debugf("recursing")
+		if strings.HasPrefix(key.Value, e.procInstPrefix) && key.Value != e.contentName {
+			name := strings.Replace(key.Value, e.procInstPrefix, "", 1)
+			procInst := xml.ProcInst{Target: name, Inst: []byte(value.Value)}
+			if err := encoder.EncodeToken(procInst); err != nil {
+				return err
+			}
+			if _, err := writer.Write([]byte("\n")); err != nil {
+				log.Warning("Unable to write newline, skipping: %w", err)
+			}
+		} else {
 
-		err = e.doEncode(encoder, value, start)
-		if err != nil {
-			return err
+			log.Debugf("recursing")
+
+			err = e.doEncode(encoder, value, start)
+			if err != nil {
+				return err
+			}
 		}
 		err = e.encodeComment(encoder, footComment(key))
 		if err != nil {
@@ -212,8 +226,14 @@ func (e *xmlEncoder) encodeMap(encoder *xml.Encoder, node *yaml.Node, start xml.
 		if err != nil {
 			return err
 		}
+		if strings.HasPrefix(key.Value, e.procInstPrefix) && key.Value != e.contentName {
+			name := strings.Replace(key.Value, e.procInstPrefix, "", 1)
+			procInst := xml.ProcInst{Target: name, Inst: []byte(value.Value)}
+			if err := encoder.EncodeToken(procInst); err != nil {
+				return err
+			}
 
-		if !strings.HasPrefix(key.Value, e.attributePrefix) && key.Value != e.contentName {
+		} else if !strings.HasPrefix(key.Value, e.attributePrefix) && key.Value != e.contentName {
 			start := xml.StartElement{Name: xml.Name{Local: key.Value}}
 			err := e.doEncode(encoder, value, start)
 			if err != nil {