/// <summary>
/// Normalize the given path string, returning a regular expression.
///
/// An empty array can be passed in for the keys, which will hold the
/// placeholder key descriptions. For example, using `/user/:id`, `keys` will
/// contain `[{ name: 'id', delimiter: '/', optional: false, repeat: false }]`.
/// </summary>
/// <param name="path">string, Regex, or array of strings</param>
/// <param name="keys"></param>
/// <param name="options"></param>
/// <returns></returns>
public static Regex PathToRegex(object path, ref List <Token> keys, PathToRegexOptions options = null)
{
if (path is Regex)
{
return(RegexToRegex((Regex)path, ref keys));
}
if (path is IEnumerable <string> )
{
return(ArrayToRegex((IEnumerable <string>)path, ref keys, options));
}
return(StringToRegex((string)path, ref keys, options));
}
/**
* Parse a string for the raw tokens.
*
* @param {string} str
* @param {Object=} options
* @return {!Array}
*/
static List <Token> Parse(string str, PathToRegexOptions options = null)
{
options = options ?? new PathToRegexOptions();
var tokens = new List <Token>();
var key = 0;
var index = 0;
var path = "";
var pathEscaped = false;
var res = PATH_REGEX.Matches(str);
foreach (Match match in res)
{
var m = match.Value;
var escaped = match.Groups[1];
var offset = match.Index;
path += str.Substring(index, offset - index);
index = offset + m.Length;
// Ignore already escaped sequences.
if (escaped.Captures.Count > 0)
{
path += escaped.Value;
pathEscaped = true;
continue;
}
var prev = "";
var name = match.Groups[2].Value;
var capture = match.Groups[3].Value;
var group = match.Groups[4].Value;
var modifier = match.Groups[5].Value;
if (!pathEscaped && path.Length > 0)
{
var k = path.Length - 1;
var c = path[k];
var matches = options.Whitelist != null?options.Whitelist.Contains(c) : true;
if (matches)
{
prev = c.ToString();
path = path.Substring(0, k);
}
}
// Push the current path onto the tokens.
if (!string.IsNullOrEmpty(path))
{
tokens.Add(new Token
{
Raw = path,
});
path = "";
pathEscaped = false;
}
var repeat = modifier == "+" || modifier == "*";
var optional = modifier == "?" || modifier == "*";
var pattern = !string.IsNullOrEmpty(capture) ? capture : group;
var delimiter = !string.IsNullOrEmpty(prev) ? prev[0] : options.Delimiter;
tokens.Add(new Token
{
Index = string.IsNullOrEmpty(name) ? key++ : (int?)null,
Name = !string.IsNullOrEmpty(name) ? name : null,
Prefix = prev,
Delimiter = delimiter,
Optional = optional,
Repeat = repeat,
Pattern = !string.IsNullOrEmpty(pattern)
? EscapeGroup(pattern)
: ("[^" + EscapeGroup(delimiter == options.Delimiter ? "" + delimiter : ("" + delimiter + options.Delimiter)) + "]+?"),
});
}
// Push any remaining characters.
if (!string.IsNullOrEmpty(path) || index < str.Length)
{
tokens.Add(new Token
{
Raw = path + str.Substring(index),
});
}
return(tokens);
}
/// <summary>
/// Create a path regex from string input.
/// </summary>
/// <param name="path"></param>
/// <param name="keys"></param>
/// <param name="options"></param>
/// <returns></returns>
public static Regex StringToRegex(string path, ref List <Token> keys, PathToRegexOptions options = null)
{
return(TokensToRegex(Parse(path, options), ref keys, options));
}
/// <summary>
/// Transform an array into a regex.
/// </summary>
/// <param name="path"></param>
/// <param name="keys"></param>
/// <param name="options"></param>
/// <returns></returns>
public static Regex ArrayToRegex(IEnumerable <string> path, ref List <Token> keys, PathToRegexOptions options = null)
{
var parts = new List <string>();
var i = 0;
foreach (var part in path)
{
parts.Add(PathToRegex(part, ref keys, options).ToString());
i++;
}
return(new Regex("(?:" + string.Join("|", parts) + ")",
RegexOptions.ECMAScript | (options.Sensitive ? RegexOptions.None : RegexOptions.IgnoreCase)));
}
/// <summary>
/// Expose a function for taking tokens and returning a Regex.
/// </summary>
/// <param name="tokens"></param>
/// <param name="keys"></param>
/// <param name="sensitive"></param>
/// <param name="strict"></param>
/// <param name="start"></param>
/// <param name="end"></param>
/// <param name="delimiter"></param>
/// <param name="endsWithChars"></param>
/// <returns></returns>
public static Regex TokensToRegex(List <Token> tokens, ref List <Token> keys, PathToRegexOptions options = null)
{
options = options ?? new PathToRegexOptions();
var endsWith = string.Join("|",
(options.EndsWith == null ? new char[] { } : options.EndsWith)
.Select(x => EscapeString("" + x))
.Concat(new string[] { "$" }));
var route = options.Start ? "^" : "";
// Iterate over the tokens and create our regex string.
for (var i = 0; i < tokens.Count; i++)
{
var token = tokens[i];
if (token.Raw != null)
{
route += EscapeString(token.Raw);
}
else
{
var capture = token.Repeat
? "(?:" + token.Pattern + ")(?:" + EscapeString(token.Delimiter?.ToString()) + "(?:" + token.Pattern + "))*"
: token.Pattern;
if (keys != null)
{
keys.Add(token);
}
if (token.Optional)
{
if (token.Prefix == null)
{
route += "(" + capture + ")?";
}
else
{
route += "(?:" + EscapeString(token.Prefix) + "(" + capture + "))?";
}
}
else
{
route += EscapeString(token.Prefix) + "(" + capture + ")";
}
}
}
if (options.End)
{
if (!options.Strict)
{
route += "(?:" + EscapeString("" + options.Delimiter) + ")?";
}
route += endsWith == "$" ? "$" : "(?=" + endsWith + ")";
}
else
{
var endToken = tokens[tokens.Count - 1];
var isEndDelimited = endToken.Raw != null
? endToken.Raw.EndsWith("" + options.Delimiter)
: endToken == null;
if (!options.Strict)
{
route += "(?:" + EscapeString("" + options.Delimiter) + "(?=" + endsWith + "))?";
}
if (!isEndDelimited)
{
route += "(?=" + EscapeString("" + options.Delimiter) + "|" + endsWith + ")";
}
}
return(new Regex(route, RegexOptions.ECMAScript | (options.Sensitive ? RegexOptions.None : RegexOptions.IgnoreCase)));
}