public static BindingTemplateToken NewExpression()

in src/Microsoft.Azure.WebJobs.Host/Bindings/Path/BindingTemplateToken.cs [37:81]

35 lines of code
8 McCabe index (conditional complexity)


        public static BindingTemplateToken NewExpression(string expression)
        {
            // BindingData takes precedence over builtins.  
            BindingParameterResolver builtin;
            BindingParameterResolver.TryGetResolver(expression, out builtin);

            // check for formatter, which is applied to finale results. 
            string format = null;
            if (builtin == null)
            {
                int indexColon = expression.IndexOf(':');
                if (indexColon > 0)
                {
                    format = expression.Substring(indexColon + 1);
                    expression = expression.Substring(0, indexColon);
                }
            }

            if (!BindingTemplateParser.IsValidIdentifier(expression))
            {
                throw new FormatException($"Invalid template expression '{expression}");
            }

            // Expression is just a series of dot operators like:  a.b.c
            var parts = expression.Split('.');

            // For backwards compat, first part can't have a '-'
            if (builtin == null)
            {
                if (parts[0].IndexOf('-') >= 0)
                {
                    throw new FormatException($"The parameter name '{parts[0]}' is invalid.");
                }
            }

            foreach (var part in parts)
            {
                if (string.IsNullOrWhiteSpace(part))
                {
                    throw new InvalidOperationException($"Illegal expression: {parts}");
                }
            }

            return new ExpressionToken(parts, format, builtin);            
        }