Expat
Stream oriented XML parser library with several useful features.
Website: https://libexpat.github.io
Platforms supported: Win32, Linux
Headers to include: expat.bi
Header version: 1.95.8
Examples: in examples/xml/
Example
`
'' XML file parser command line tool based on libexpat
'' Can use zstring or wstring (libexpat or libexpatw):
'#define XML_UNICODE
#include Once "expat.bi"
#include Once "crt/mem.bi"
#ifndef False
#define False 0
#endif
#define NULL 0
Const BUFFER_SIZE = 1024
Type Context
As Integer nesting
As XML_char * (BUFFER_SIZE+1) text
As Integer textlength
End Type
Dim Shared As Context ctx
'' Callback called by libexpat when begin of XML tag is found
Sub elementBegin cdecl _
( _
ByVal userdata As Any Ptr, _
ByVal element As Const XML_char Ptr, _
ByVal attributes As Const XML_char Ptr Ptr _
)
'' Show its name
Print Space(ctx.nesting);*element;
'' and its attributes (attributes are given as an array of XML_char pointers
'' much like argv, for each attribute there will apparently be the one
'' element representing the name and a second element representing the
'' specified value)
While (*attributes)
Print " ";**attributes;
attributes += 1
Print "='";**attributes;"'";
attributes += 1
Wend
Print
ctx.nesting += 1
ctx.text[0] = 0
ctx.textlength = 0
End Sub
'' Callback called by libexpat when end of XML tag is found
Sub elementEnd cdecl(ByVal userdata As Any Ptr, ByVal element As Const XML_char Ptr)
'' Show text collected in charData() callback below
Print Space(ctx.nesting);ctx.text
ctx.text[0] = 0
ctx.textlength = 0
ctx.nesting -= 1
End Sub
Sub charData cdecl _
( _
ByVal userdata As Any Ptr, _
ByVal chars As Const XML_char Ptr, _ '' Note: not null-terminated
ByVal length As Integer _
)
'' This callback will apparently recieve every data between xml tags
'' (really?), including newlines and space.
'' Append to our buffer, if there still is free room, so we can print it out later
If (length <= (BUFFER_SIZE - ctx.textlength)) Then
memcpy(@ctx.text[ctx.textlength], @chars[0], length * SizeOf(XML_char))
ctx.textlength += length
ctx.text[ctx.textlength] = 0
End If
End Sub
''
'' Main
''
Dim As String filename = Command(1)
If (Len(filename) = 0) Then
Print "Usage: expat <xmlfilename>"
End 1
End If
Dim As XML_Parser parser = XML_ParserCreate(NULL)
If (parser = NULL) Then
Print "XML_ParserCreate failed"
End 1
End If
''XML_SetUserData(parser, userdata_pointer)
XML_SetElementHandler(parser, @elementBegin, @elementEnd)
XML_SetCharacterDataHandler(parser, @charData)
If (Open(filename, For Input, As #1)) Then
Print "Could not open file: '";filename;"'"
End 1
End If
Static As UByte buffer(0 To (BUFFER_SIZE-1))
Dim As Integer reached_eof = False
Do
Dim As Integer size = BUFFER_SIZE
Dim As Integer result = Get(#1, , buffer(0), size, size)
If (result Or (size <= 0)) Then
Print "File input error"
End 1
End If
reached_eof = (EOF(1) <> False)
If (XML_Parse(parser, @buffer(0), size, reached_eof) = False) Then
Print filename & "(" & XML_GetCurrentLineNumber(parser) & "): Error from XML parser: "
Print *XML_ErrorString(XML_GetErrorCode(parser))
End 1
End If
Loop While (reached_eof = False)
XML_ParserFree(parser)
`