Simple and straightforward XML parsing and composing library.
The example project now contains an additional application which includes a pretty large demo xml file:
The maximum memory buffer size (parameter) is set smaller than the xml file size
One FB gets the recipe names from the file and stores the location in the file where the recipe is.
Another FB can read the children of the recipe. This way not all data has to be parsed, but only the required data. This keeps both the memory buffer small, but also the structures which contain the data.
Download Library v0.4.0.0
Download Example v0.4.0.0
VAR
XML : FB_XMLControl;
Buffer: STRING(GVL_Param_XmlControl.udiMaxFileSize);
// or buffer as an array of BYTE
Buffer: ARRAY [0..GVL_Param_XmlControl.udiMaxFileSize] OF BYTE;
END_VAR
// call
XML.pBuffer: = ADR (buffer);
XML.LenBuffer: = SIZEOF (buffer);
Add your own preferred XML fileheader i.e.:
<?xml version="1.0" encoding="UTF-8"?>
// call
XML.WriteDocumentHeader( '<?xml version="1.0" encoding="UTF-8"?>');
Compose a tag with a parameter:
<mytag paraname="11"></mytag>
// call
XML.newTag(sTagName: = 'MyTag');
XML.newParameter(Name: = 'ParaName', Parameter: = 11);
XML.CloseTag();
Add a value to the tag:
<mytag> MyText </ MyTag></mytag>
// call
XML.newTag(Name := 'MyTag');
XML.newTagData(TagData :='MyText');
XML.CloseTag();
// call
XML.toStartBuffer();
// call
XML.newComment(sTagName: = 'MyComment');
// call
XML.NextTag();
// call
XML.NextParameter(Parameter: = LastValue);
Feedback: Parameter returns the value found (string)
FB_FileControl: This function block can open, close, read and save a file from and to a generic PLC memory buffer. It can also read a small portions (chunks) of the file from disk to memory which enables you to load larger files in small portions.
FB_StringBuffer: Acts as an IO stream buffer for use with FB_XmlControl. Data can be treated as STRING or array of bytes. The
stringBuffer can also be used as a basis for other purposes like txt, csv, etc, etc.
FB_XmlControl: Organizes Parsing and Composing of XML data. Filebuffersize can be set via library parameter (Gvl_Param_XmlControl)
Note:
Files do not necessarily need to be in a .xml format so you can use filecontrol to access or write any type of file.
Offcourse parsing and composing via xmlcontrol is only supported for xml formatted files.
Download Library v0.4.0.0
Download Example v0.4.0.0
@timvh for providing partial filereading/parsing