/// <summary>
/// Creates a DynamicString instance from the given expression.
/// </summary>
/// <param name="expression">
/// A string that have runtime resolved sections marked with the syntax "$(resolver-name)".
/// For example: "The current time is $(get-current-time)".
/// To specify a single literal '$' character in the expression, specify two '$' characters; that is,
/// "$$".
/// </param>
/// <returns>The created DynamicString instance.</returns>
public static DynamicString FromString(string expression)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
DynamicString newCfgString = new DynamicString();
int searchIdx = 0;
int searchOffset = 0;
while (searchIdx + searchOffset < expression.Length)
{
int dollarIdx = expression.IndexOf('$', searchIdx + searchOffset);
if (dollarIdx == -1)
{
/// No more runtime sections, add the remaining part of the expression to the
/// section list.
newCfgString.sections.Add(expression.Substring(searchIdx).Replace("$$", "$"));
newCfgString.runtimeFlags.Add(false);
break;
}
else
{
/// Potentially runtime section found, we have to check it.
if (expression.Length > dollarIdx + 1 && expression[dollarIdx + 1] == '$')
{
/// No, it's not a runtime section, just one simple '$' character escaped.
searchOffset = dollarIdx + 2 - searchIdx;
continue;
}
else if (expression.Length > dollarIdx + 1 && expression[dollarIdx + 1] == '(')
{
/// We have found the beginning of a runtime section, so we have to store the
/// previous non-runtime section.
if (dollarIdx - searchIdx > 0)
{
newCfgString.sections.Add(
expression.Substring(searchIdx, dollarIdx - searchIdx).Replace("$$", "$"));
newCfgString.runtimeFlags.Add(false);
}
/// Now parse the runtime section.
int sectionEndIdx = expression.IndexOf(')', dollarIdx);
if (sectionEndIdx != -1 && sectionEndIdx - dollarIdx > 2)
{
/// End of the runtime section has been found
string runtimeSection = expression.Substring(dollarIdx + 2, sectionEndIdx - (dollarIdx + 2));
newCfgString.sections.Add(runtimeSection);
newCfgString.runtimeFlags.Add(true);
searchIdx = sectionEndIdx + 1;
searchOffset = 0;
}
else
{
/// Syntax error
throw new ConfigurationException(string.Format("Syntax error in DynamicString expression: {0}", expression));
}
}
else
{
/// Syntax error
throw new ConfigurationException(string.Format("Syntax error in DynamicString expression: {0}", expression));
}
}
}
return(newCfgString);
}
/// <summary>
/// Checks whether this DynamicString has the same value as the specified DynamicString.
/// </summary>
/// <param name="other">The DynamicString to test.</param>
/// <returns>True if other DynamicString has the same value as this DynamicString.</returns>
public bool Equals(DynamicString other)
{
return(other.Value == this.Value);
}