Best Practice Advice XML

[Fraser]

Hi,

I'm needing to update an xml file by inserting a new node. First I need to
load the xml into a XmlDocument from file.

In the first run, the file won't exist and I will have to create a new
XmlDocument. What is the best way to do this ?

I'm thinking just catching an exception and building a new doc isn't the
best way of doing this.

If i check to see if the file exists, this is not neccessarily the best way
since the file might be corrupt. I can program this, but I'm asking for
advice on the best way of doing this. Can anyone advise me?

public void savePlayer()

{

XmlDocument xmldoc = new XmlDocument();

XmlNode members;

try

{

StreamReader xmlfile = new StreamReader("m embers.xml");

xmldoc.Load(xml file);

xmlfile.Close() ;

//get the members node

members = xmldoc.Document Element;

}

catch

{

//the file doesn't exist so we must create a new document

//let's add the XML declaration section

XmlNode xmlnode=xmldoc. CreateNode(XmlN odeType.XmlDecl aration,"","");

xmldoc.AppendCh ild(xmlnode);


//let's add the node element

members = xmldoc.CreateEl ement("members" );

xmldoc.AppendCh ild(members);

}

XmlNode member = xmldoc.CreateEl ement("member") ;





//the display name

XmlElement displayname = xmldoc.CreateEl ement("displayn ame");

XmlText displayname_val ue = xmldoc.CreateTe xtNode("value") ;

displayname.App endChild(displa yname_value);

member.AppendCh ild(displayname ); //add the username to the player


members.AppendC hild(player);

xmldoc.Save("me mbers.xml");

}

[seani]

Re: Best Practice Advice XML

On Mon, 23 May 2005 17:33:05 +0100, Fraser wrote:
[color=blue]
> Hi,
>
> I'm needing to update an xml file by inserting a new node. First I need
> to load the xml into a XmlDocument from file.
>
> In the first run, the file won't exist and I will have to create a new
> XmlDocument. What is the best way to do this ?
>
> I'm thinking just catching an exception and building a new doc isn't the
> best way of doing this.
>[/color]

And I'd suggest that your instinct is correct. The fact that a file
doesn't exist *is* an "exception" al condition; exceptions are suitable for
this task. The mindset that exception===err or is just dogma.

However:

1) Ensure you only catch ans suitably code for your
"file-does-not-exist" exception, rather than every exception.

2) You'll need to cater for corrupt files whatever.

[color=blue]
> If i check to see if the file exists, this is not neccessarily the[/color]
best[color=blue]
> way since the file might be corrupt. I can program this, but I'm asking
> for advice on the best way of doing this. Can anyone advise me?
>
>[sample code snipped][/color]

[seani]

Re: Best Practice Advice XML

On Tue, 24 May 2005 00:22:44 +0200, seani wrote:
[color=blue]
> On Mon, 23 May 2005 17:33:05 +0100, Fraser wrote:
>[color=green]
>> Hi,
>>
>> I'm needing to update an xml file by inserting a new node. First I need
>> to load the xml into a XmlDocument from file.
>>
>> In the first run, the file won't exist and I will have to create a new
>> XmlDocument. What is the best way to do this ?
>>
>> I'm thinking just catching an exception and building a new doc isn't the
>> best way of doing this.
>>
>>[/color]
> And I'd suggest that your instinct is correct. The fact that a file
> doesn't exist *is* an "exception" al condition; exceptions are suitable for
> this task. The mindset that exception===err or is just dogma.
>[/color]

Oops-a-daisy, I meant to say "your instinct is *incorrect*".

The rest of my post may seem more consistent now.