XML / XSL

Christopher Duncan10-Jul-02 5:44

Christopher Duncan

10-Jul-02 5:44

Christopher,

I'm looking to do a conversion from Windows Media playlists (.asx, etc.), which is in an xml format, to Winamp .pls for use in the Turtle Beach AudioTron file player I just bought (extremely cool gizmo, by the way).

I haven't done anything with xml/xsl yet, but your description of the xsl transform language sounds perfect. Could you point me to some documentation on this feature? I'm not looking to really learn xml in full just yet, I merely have a single problem I need to solve as simply & quickly as I can make it.

Thanks!

Chistopher Duncan
Author - The Career Programmer: Guerilla Tactics for an Imperfect World (Apress)

Christopher Lord10-Jul-02 9:42

Christopher Lord

10-Jul-02 9:42

XSL is mainly for changing XML dialects (XHTML included).

In order to transform to non-xml files, like M3U or TXT, you have to either craft your transform very carefully (many formats will not work because they may use tags which conflict) or use something like FOP (http://xml.apache.org/fop/index.html)

You'll also have to watch out for whitespace, since most plain-text formats are very picky. Many xsl engines let you use absolute whitespace.

Christopher Duncan10-Jul-02 12:28

Christopher Duncan

10-Jul-02 12:28

Thanks, Christopher.

Looks like the quick & dirty way is just a fast MFC dialog based app and a little string processing. Appreciate the link!

Chistopher Duncan
Author - The Career Programmer: Guerilla Tactics for an Imperfect World (Apress)

MS le Roux1-Jul-02 22:07

MS le Roux

1-Jul-02 22:07

Scripting is necessary if you want to use the DOM to process XML. If you don't want to do that, you can use XSLT.

XSLT is pretty cool, but it is quite challenging to master. You can take a look at 2 XSLT articles I wrote (while I was still using the name MarSCoZa).

Erik Westermann3-Jul-02 1:59

Erik Westermann

3-Jul-02 1:59

One option is to use th DSO (Data Source Object) and a tiny bit of scripting (2-3 lines) to bind a control like a lisst box to an XML data source. Other than that, you can combine your XML with XSL to get IE to render an HTML-like document.

Erik Westermann
Author, Learn XML In A Weekend (Summer 2002)

9-Jul-02 16:28

Definitely do some reading at TopXML Rose | [Rose]

Updating an XML file from VC6.0

Richard Jones10-Jul-02 4:29

Richard Jones

10-Jul-02 4:29

Check out an article about CMarkupArchive by Jonathan de Halleux.
I use it in my apps.

Jan R Hansen26-Jun-02 3:11

Jan R Hansen

26-Jun-02 3:11

Hi,

I've just got started with XML and VC6.0 (thanks to Tom Archer : http://codeguru.earthweb.com/xml/XMLDOMFromVC.html - great explanation/tutorial !!!) and I'm wondering how I can write data back to an XML file. I use the DOM as described in the article to read data from a file to internal datastructures - but I need to update different values in my XML file after updating the datastructures. How is this done most easily ? Currently, I see two ways of doing it : writing the XML file as ascii based on the data or using the DOM to generate a file. The first I can do ;o) - but how is the latter done ? And is that the "right" way to do it ?

Thanks in advance.

Best regards

Jan Hansen

act_x27-Jun-02 5:43

act_x

27-Jun-02 5:43

u have seem to have solved the question about retrieving data.

XML DOM supports for Data insertion . Additionally it is advantageous as you will follow a syntax to add data . In case the DOM object could not add data it will notify . I think that using the DOM to insert Data is the way to go about this .

Also try exploring SAX .

[James Pullicino]30-Jun-02 23:52

[James Pullicino]

30-Jun-02 23:52

Use the DOM. To set the value of an element use the same method you used to get the text, but instead set it.

Finally call the save method of the DOMDocument to save your DOM as an XML file.

Drinking In The Sun
Forgot Password?

Ranjan Banerji2-Jul-02 5:45

Ranjan Banerji

2-Jul-02 5:45

You can use DOM to both modify data ( change values of existing nodes) and to modify the structure of your XML (Add or remove nodes).

DOMDocument has functions like CreatNode, CreateElement etc. Once you create a Node you can insert it or append it to an existing to node in your XML. Think of it as dealing with a tree structure.

Changing the value is easier. You just set the new value.

For example node.firstChild.Attributes.getNamedItem("blah").Text = "Yoooo Hoooo"

This will find an attribute named blah in your node and set its text to "Yoooo Hoooo"

You can try doing this yourself by editing the text but that would be reinventing the wheel.

Hope this helped. You may want to look into MSDN for more precise syntax and examples.

Jan R Hansen2-Jul-02 21:13

Jan R Hansen

2-Jul-02 21:13

Thanks a lot !

I have looked (a little) at the "root-object", and there doesn't seem to be a "flush-to-disk" operation. During the lifetime of my application, I would like to ensure that changes to the data in the file are written - just to prevent a crash of the framework I'm working inside from deleting changes. Any idea how this is done ? Or do I have to sort of close the document?

/Jan

New subquestion : how to format the XML nicely ?

Ranjan Banerji3-Jul-02 6:27

Ranjan Banerji

3-Jul-02 6:27

You need to look up help/documention for DOMDocument. It has a funtion called save that will save your XML. DOMDocument is where you load your XML. Then you use the nodes to manipulate the content. Then you save the DOMDocument.

Jan R Hansen8-Jul-02 12:21

Jan R Hansen

8-Jul-02 12:21

Hi all, and thanks a lot for the help so far.

I now read data, delete some data from my XML tree ,and insert some data. Then I save the data to the file I loaded it from. Everything works fine - except for the formatting. I tend to format my XML data C-like, with tabular indents etc. This is kept in the part of the XML tree not modified from C++ - but the data added from C++ is written in one long line like this
<parent><child1>blah<child2>blah

- any way I can ask the XML engine to format things "my way" or a "standard way". By the way, the data not modified from C++ is getting (damn, whats the word...) truncated/fitted/"replace-one-or-more-newlines-with-only-one-newline". But tabs are kept.

Any hints, oh allmighty gurus of knowledge ;o)

Thanks in advance
/Jan

Re: New subquestion : how to format the XML nicely ?

Anonymous9-Jul-02 16:50

Anonymous

9-Jul-02 16:50

Read here for possible information on formatting needs: Format XML/XSL for Documentation

Repeating elements in a sequence.

nay25-Jun-02 5:28

nay

25-Jun-02 5:28

I want some child elements in an element to repeat. But I also don't care what order. I cant use the "all" compositor because the maxOccurance can only be 1. Here's what I have tried but I still don't have the result I want. The way I thought this should work is "line" and "field" should repeat as many times as needed.

<xsd:element name="group">
	<xsd:complexType>
	<xsd:sequence>
		<xsd:element name="name" minOccurs = "1" maxOccurs ="1"/>
		
		<xsd:choice minOccurs = "0" maxOccurs = "unbounded">
			<xsd:element ref="line" minOccurs = "0" maxOccurs = "unbounded"/>
			<xsd:element ref="field" minOccurs = "0" maxOccurs = "unbounded"/>
		</xsd:choice>

		<xsd:element ref="TextFieldGroup" minOccurs = "0" maxOccurs = "unbounded"/>
	</xsd:sequence>
		<xsd:attribute name="groupType" use = "optional"/>
	</xsd:complexType>
	</xsd:element>

Any ideas on what I can do?

nay

retrieve data with types from XML

jkgh20-Jun-02 7:15

jkgh

20-Jun-02 7:15

I'm quite late in the day to XML and have only used XSD schema.

Is there a way to get a typed value from a XML DOM, particularly in the case of a xsd:dateTime type, without explicitly going through the SOM to find the type. I am look for something not too dissimilar to nodeTypedValue for XSD.

Timezoned dates and times are a particulr problem but I've just stumbled on a newsgroup thread that uses XSD but sets the nodeType to the XDR equivilent to make getting and setting values within the DOM easy. I was planning to include the XDR type as a string in the XML, and take the hit of xdr being non-standard or dissappearing.

Al.

Alice thought that running very fast for a long time would get you to somewhere else. " A very slow kind of country!" said the queen. "Now, here , you see, it takes all the running you can do, to keep in the same place".

XML Uses

18-Jun-02 0:30

Hi there, I am very new to the new technologies (.NET and XML etc) because my work as a developer at this company does not allow for further training.....

My question, I work alot with databases (access mostly).... how will XML make my life better? I have read in MSDN about it a bit, but would like to know the exact uses etc, because I am getting confused by what other people tell me.

Thanks

MS le Roux18-Jun-02 2:16

MS le Roux

18-Jun-02 2:16

There was a discussion about this in this earlier thread.
Basically what's nifty about XML is the fact that it is plain text, making it very generic. The basic XML concept is very simple, and it has a great many uses.

Michael A. Barnhart20-Jun-02 10:11

Michael A. Barnhart

20-Jun-02 10:11

As far as uses go you have to open your mind a little. One that is very attractive to me is being able to integrate data in a more data driven nature. Take a look at the Apache Cocoon framework for a sample of what I mean by this.

To be conscious that you are ignorant of the facts is a great step towards Knowledge. Benjamin Disraeli

Christopher Lord23-Jun-02 8:04

Christopher Lord

23-Jun-02 8:04

XML is awesome for several reasons.

Number one is that it is standard. This is the prime reason XML should be considered for anything at all.

Next, it is rigid, and fails with a parse error if it is not. This strongly encourages clean files, and helps with performance, among other things.

Another thing is XSL. Any standard XML document could be transformed into any sort of file with this powerful technology. Raw ASCII, HTML, DHTML, perhaps even things like postscript and CSS.

The XmlDOM and XPath. This lets any program work with XML in a standardized way. Most programs I make with Xml support use the Dom extensivly.

Miguel Lopes10-Jul-02 8:28

Miguel Lopes

10-Jul-02 8:28

XML, the downside:

-XML is a lot slower when searched, compared with normal database queries.
-XML adds a lot of overhead, means bigger DB
-XML parsers are usually slow
-.NET implementation of XML is REALLY SLOW and requires managed code, which sucks hard

XML, the upside:

-universal
-simple tree structure: even a child can read it
-can be created/edited with NOTEPAD, the best application ever written
////////////////////////////////////////////////////////////////////
// NOW THE UPSIDE THAT YOU WERE ASKING ABOUT
//
// you can put in a single DB cell a complex and dinamic structure!
// That means that the information saved in the DB can have a dinamic structure WITHOUT changing the DB!!
////////////////////////////////////////////////////////////////////

Paul Watson12-Jul-02 1:44

Paul Watson

12-Jul-02 1:44

Miguel Lopes wrote:
-XML adds a lot of overhead, means bigger DB

Have you ever zipped/compressed an XML file?

Man, I grinned from ear to ear when I saw the compression ratio. Zip loves all those repetitive tags.

So for transfer it is not as big a problem as some people make out. Of course when you are working with the XML it has to be unzipped and then the size can be a pain.

regards,
Paul Watson
Bluegrass
Cape Town, South Africa

The greatest thing you'll ever learn is just to love, and to be loved in return - Moulin Rouge

Alison Pentland wrote:
I now have an image of you in front of the mirror in the morning, wearing your knickers, socks and shoes trying to decided if they match!