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UserAgentParser.go
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/
UserAgentParser.go
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package parser
import (
"errors"
"github.com/tutuvss/sip/core"
"github.com/tutuvss/sip/header"
"strings"
)
/** SIPParser for UserAgent header.
*/
type UserAgentParser struct {
HeaderParser
}
/** Constructor
* @param userAgent - UserAgent header to parse
*
*/
func NewUserAgentParser(userAgent string) *UserAgentParser {
this := &UserAgentParser{}
this.HeaderParser.super(userAgent)
return this
}
/** Constructor
* @param lexer - the lexer to use.
*/
func NewUserAgentParserFromLexer(lexer core.Lexer) *UserAgentParser {
this := &UserAgentParser{}
this.HeaderParser.superFromLexer(lexer)
return this
}
/** parse the String message
* @return SIPHeader (UserAgent object)
* @throws SIPParseException if the message does not respect the spec.
*/
func (this *UserAgentParser) Parse() (sh header.Header, ParseException error) {
userAgent := header.NewUserAgent()
var ch byte
lexer := this.GetLexer()
this.HeaderName(TokenTypes_USER_AGENT)
if ch, _ = lexer.LookAheadK(0); ch == '\n' {
return nil, errors.New("empty header")
}
// mandatory token: product[/product-version] | (comment)
for ch, ParseException = lexer.LookAheadK(0); ch != '\n' && ParseException == nil; ch, ParseException = lexer.LookAheadK(0) {
if ch == '(' {
comment, _ := lexer.Comment()
userAgent.AddProductToken("(" + comment + ")")
} else {
var tok string
tok, ParseException = lexer.GetString('/')
if ParseException != nil {
tok = lexer.GetRest()
userAgent.AddProductToken(strings.TrimSpace(tok))
break
} else {
if tok[len(tok)-1] == '\n' {
tok = strings.TrimSpace(tok)
}
userAgent.AddProductToken(tok)
}
}
}
return userAgent, nil
}