ConfigurationSection with nested ConfigurationElementCollections - configurationsection

Question

Hopefully, I can present this problem to the brain trust of this site and someone will see my mistake.
I am working on a project where email text needs to be "mail merged" with information found in the properties of various internal classes. A typical symbol found in the email text might look like "{member name}, {mobile phone}, etc."
I would like to define the symbols and the classes they are found in using a ConfigurationSection in web.config. Here is my proposed configuration section:
<EmailSymbols>
<SymbolClasses>
<SymbolClass name="OHMember">
<Symbol name="Member Name" template="{0} {1}">
<add index="0" value="SMFirstName" />
<add index="1" value="SMLastName" />
</Symbol>
<Symbol name="Phone" template="{0}">
<add index="0" value="SMPhone" />
</Symbol>
</SymbolClass>
<SymbolClass name="Form">
<Symbol name="Contact Name" dataname="ContactName" />
</SymbolClass>
</SymbolClasses>
</EmailSymbols>
...and the code that I am trying to parse it with:
public class EmailSymbols : ConfigurationSection {
[ConfigurationProperty("SymbolClasses", IsRequired = true)]
public SymbolClassCollection SymbolClasses {
get {
return this["SymbolClasses"] as SymbolClassCollection;
}
}
}
[ConfigurationCollection(typeof(SymbolClass), AddItemName = "SymbolClass")]
public class SymbolClassCollection : ConfigurationElementCollection {
protected override ConfigurationElement CreateNewElement() {
return new SymbolClass();
}
protected override object GetElementKey(ConfigurationElement element) {
return ((SymbolClass)element).Name;
}
}
[ConfigurationCollection(typeof(Symbol), AddItemName = "Symbol")]
public class SymbolClass : ConfigurationElementCollection {
[ConfigurationProperty("name", IsRequired = true, IsKey = true)]
public String Name {
get {
return this["name"] as String;
}
}
protected override ConfigurationElement CreateNewElement() {
return new Symbol();
}
protected override object GetElementKey(ConfigurationElement element) {
return ((Symbol)element).Name;
}
}
[ConfigurationCollection(typeof(TemplateValue), AddItemName = "add")]
public class Symbol : ConfigurationElementCollection {
[ConfigurationProperty("name", IsRequired = true, IsKey = true)]
public String Name {
get {
return this["name"] as String;
}
}
[ConfigurationProperty("template", IsRequired = false)]
public String Template {
get {
return this["template"] as String;
}
}
[ConfigurationProperty("dataname", IsRequired = false)]
public String DataName {
get {
return this["dataname"] as String;
}
}
protected override ConfigurationElement CreateNewElement() {
return new TemplateValue();
}
protected override object GetElementKey(ConfigurationElement element) {
return ((TemplateValue)element).Index;
}
}
public class TemplateValue : ConfigurationElement {
[ConfigurationProperty("index", IsRequired = false, IsKey = true)]
public Int32 Index {
get {
return this["index"] == null ? -1 : Convert.ToInt32(this["index"]);
}
}
[ConfigurationProperty("value", IsRequired = false)]
public String Value {
get {
return this["value"] as String;
}
}
}
When I parse the section with this statement:
symbols = ConfigurationManager.GetSection("EmailSymbols") as EmailSymbols;
I receive this error message: "Unrecognized element 'Symbol'."
This is simply an area of .NET that I don't know my way around. Any help that anyone could give would be most appreciated.
Does my XML definition make sense and is it in the correct form? I want a collection of SymbolClass, each containing a collection of Symbol, each containing a collection of TemplateValue.
Again, thanks for your help.
Best Regards,
Jimmy

Answer 1

You could try to override the Init() method of the SymbolClass class:
protected override void Init()
{
base.Init();
this.AddElementName = "Symbol";
}
You an also remove [ConfigurationCollection(typeof(SymbolClass), AddItemName = "SymbolClass")] and the others like it from above the class declarations as their not doing anything.