GoToSocial/vendor/github.com/go-xmlfmt/xmlfmt/xmlfmt.go

57 lines
1.7 KiB
Go

////////////////////////////////////////////////////////////////////////////
// Porgram: xmlfmt.go
// Purpose: Go XML Beautify from XML string using pure string manipulation
// Authors: Antonio Sun (c) 2016-2019, All rights reserved
////////////////////////////////////////////////////////////////////////////
package xmlfmt
import (
"regexp"
"strings"
)
var (
reg = regexp.MustCompile(`<([/!]?)([^>]+?)(/?)>`)
// NL is the newline string used in XML output, define for DOS-convenient.
NL = "\r\n"
)
// FormatXML will (purly) reformat the XML string in a readable way, without any rewriting/altering the structure
func FormatXML(xmls, prefix, indent string) string {
src := regexp.MustCompile(`(?s)>\s+<`).ReplaceAllString(xmls, "><")
rf := replaceTag(prefix, indent)
return (prefix + reg.ReplaceAllStringFunc(src, rf))
}
// replaceTag returns a closure function to do 's/(?<=>)\s+(?=<)//g; s(<(/?)([^>]+?)(/?)>)($indent+=$3?0:$1?-1:1;"<$1$2$3>"."\n".(" "x$indent))ge' as in Perl
// and deal with comments as well
func replaceTag(prefix, indent string) func(string) string {
indentLevel := 0
return func(m string) string {
// head elem
if strings.HasPrefix(m, "<?xml") {
return NL + prefix + strings.Repeat(indent, indentLevel) + m
}
// empty elem
if strings.HasSuffix(m, "/>") {
return NL + prefix + strings.Repeat(indent, indentLevel) + m
}
// comment elem
if strings.HasPrefix(m, "<!") {
return NL + prefix + strings.Repeat(indent, indentLevel) + m
}
// end elem
if strings.HasPrefix(m, "</") {
indentLevel--
return NL + prefix + strings.Repeat(indent, indentLevel) + m
}
defer func() {
indentLevel++
}()
return NL + prefix + strings.Repeat(indent, indentLevel) + m
}
}