Adding a new entry in the config in code

I have the following code which takes in a string representing an element in my settings/config file. It then returns the value of that element.

Code:

---

public string GetAppConfigValue(string SettingName)
{
            string sContents;
            ConfigurationSectionGroup grpApp = config.GetSectionGroup("applicationSettings");
            ClientSettingsSection secPropSet = (ClientSettingsSection)grpApp.Sections[sSettingsSection];
            secPropSet.SectionInformation.ForceSave = true;
            SettingElement elm = secPropSet.Settings.Get(SettingName);
            if (elm == null)
            {
                sContents = SettingName + " is missing!";
            }
            else
            {
                sContents = elm.Value.ValueXml.InnerText.Trim();
            }
            return sContents;
}

---

This all works fine but what I need to do is create this setting with a string "NOT AVAILABLE"if it is not there.

I think its something along the lines off :

Code:

---

SettingElement newElem = new SettingElement(SettingName, SettingsSerializeAs.String);
secPropSet.Settings.Add(newElem);
//How do i add "NOT AVAILABLE" to its value

---

The above code adds this to the config "<setting name="NEW_ATTRIBUTE" serializeAs="String" />" but it has no value and no closing tag " </setting>"
Man am I ever confused :-(

SettingElement has a Value property, you need to populate that appropriately before the Add() call. MSDN has lots of info about it.

Thanks Wossy.

I'm still having tons of trouble with this one though. I have the following :

Code:

---

SettingElement newElem = new SettingElement(SettingName, SettingsSerializeAs.String);
SettingValueElement setValue;
System.Xml.XmlNode xNode = new System.Xml.XmlNode();
xNode.Value = "TESTING";
setValue.ValueXml = xNode;
newElem.Value = setValue;
secPropSet.Settings.Add(newElem);

---

All i get is :

Cannot create an instance of the abstract class or interface 'System.Xml.XmlNode'

However the value of newElem requires something of XMLNode type.

I have managed to get a bit further :

Code:

---

SettingElement newElem = new SettingElement(SettingName, SettingsSerializeAs.String);
System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
System.Xml.XmlNode n = doc.CreateNode(System.Xml.XmlNodeType.Text, "bigWoof", "");
SettingValueElement setValue = new SettingValueElement();
setValue.ValueXml = n;
newElem.Value = setValue;
secPropSet.Settings.Add(newElem);

---

This code generates the following :

Code:

---

<setting name="HELPURL" serializeAs="String">bigWoof</setting>

---

Note the lack of <value></value> tags.

When I try and read the element I get the following :
The configuration section cannot contain a CDATA or text element.

Man this is doing my head in.

I use my own class so I must confess I'm not used to the built in save settings functions you are using, but my class works pretty well. Here are the two functions in their entirety:

Code:

---

//Written by Keith Ratliff - if you use, please leave this comment in your code.
                static object oKey = new object();
                public static void SaveSetting(string sSetting, string sValue)
                {
                        lock(oKey){
                                string sFolder = System.Windows.Forms.Application.StartupPath;
                                System.Xml.XmlDocument oXD = new System.Xml.XmlDocument();
                                try{
                                oXD.Load(sFolder + "/settings.xml");
                                }catch(System.Exception)
                                {
                                        string sNewSettings = @"<Root></Root>";
                                        oXD.LoadXml(sNewSettings);
                                }
                                if(oXD.DocumentElement.SelectSingleNode(sSetting) != null)
                                        oXD.DocumentElement.RemoveChild(oXD.DocumentElement.SelectSingleNode(sSetting));
                                System.Xml.XmlNode oNode = oXD.CreateNode(System.Xml.XmlNodeType.Element.ToString().ToLower(), sSetting, "");
                                oNode.InnerXml = sValue;
                                oXD.DocumentElement.AppendChild(oNode);
                                oXD.Save(sFolder + "/settings.xml");
                        }
                }
               
                public static string GetSetting(string sSetting)
                {
                        string sRet = "";
                        bool bOK = true;
                        lock(oKey){
                                string sFolder = System.Windows.Forms.Application.StartupPath;
                                System.Xml.XmlDocument oXD = new System.Xml.XmlDocument();
                                try{
                                        oXD.Load(sFolder + "/settings.xml");
                                }catch(System.Exception){
                                        sRet = "";
                                        bOK = false;
                                }
                               
                                System.Xml.XmlNode oNode = null;
                                if(bOK){
                                        oNode = oXD.DocumentElement.SelectSingleNode(sSetting);
                                        if(oNode == null) {
                                                sRet = "";
                                                bOK = false;
                                        }
                                }
                               
                                if(bOK){
                                        sRet = oNode.InnerXml;
                                }
                        }
                        return sRet;
                }

---

If you want the error message you are describing (when the node doesn't already exist at all) just change
if(oNode == null) {
sRet = "";
bOK = false;
}

to

if(oNode == null) {
sRet = "NOT AVAILABLE!";
bOK = false;
}

EDIT: Adding thread safety.

Quote:

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Originally Posted by venerable bede

The above code adds this to the config "<setting name="NEW_ATTRIBUTE" serializeAs="String" />" but it has no value and no closing tag " </setting>"
Man am I ever confused :-(

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Taking a second look at your original, I should probably point something out about XML.

When a tag has no data inside, it is allowed to close itself by having a slash before the closing ">"

For example:
<SampleTag></SampleTag>

is exactly the same as
<SampleTag />

Notice the "/>" in the second one? That means it closes itself.

HTH