什么是一个好的完整正则表达式或其他一些过程,将采取标题:
如何将标题更改为URL的一部分,如堆栈溢出?
然后把它变成
how-do-you-change-a-title-to-be-part-of-the-url-like-stack-overflow
在堆栈溢出的seo友好的url中使用?
我使用的开发环境是Ruby on Rails,但是如果有一些其他特定于平台的解决方案(。NET, PHP, Django),我也很想看到这些。
我相信我(或其他读者)在不同的平台上也会遇到同样的问题。
我使用自定义路由,我主要想知道如何改变字符串的所有特殊字符被删除,它都是小写的,所有空白被替换。
下面是Jeff代码的我的版本。我做了以下修改:
The hyphens were appended in such a way that one could be added, and then need removing as it was the last character in the string. That is, we never want “my-slug-”. This means an extra string allocation to remove it on this edge case. I’ve worked around this by delay-hyphening. If you compare my code to Jeff’s the logic for this is easy to follow.
His approach is purely lookup based and missed a lot of characters I found in examples while researching on Stack Overflow. To counter this, I first peform a normalisation pass (AKA collation mentioned in Meta Stack Overflow question Non US-ASCII characters dropped from full (profile) URL), and then ignore any characters outside the acceptable ranges. This works most of the time...
... For when it doesn’t I’ve also had to add a lookup table. As mentioned above, some characters don’t map to a low ASCII value when normalised. Rather than drop these I’ve got a manual list of exceptions that is doubtless full of holes, but it is better than nothing. The normalisation code was inspired by Jon Hanna’s great post in Stack Overflow question How can I remove accents on a string?.
The case conversion is now also optional.
public static class Slug
{
public static string Create(bool toLower, params string[] values)
{
return Create(toLower, String.Join("-", values));
}
/// <summary>
/// Creates a slug.
/// References:
/// http://www.unicode.org/reports/tr15/tr15-34.html
/// https://meta.stackexchange.com/questions/7435/non-us-ascii-characters-dropped-from-full-profile-url/7696#7696
/// https://stackoverflow.com/questions/25259/how-do-you-include-a-webpage-title-as-part-of-a-webpage-url/25486#25486
/// https://stackoverflow.com/questions/3769457/how-can-i-remove-accents-on-a-string
/// </summary>
/// <param name="toLower"></param>
/// <param name="normalised"></param>
/// <returns></returns>
public static string Create(bool toLower, string value)
{
if (value == null)
return "";
var normalised = value.Normalize(NormalizationForm.FormKD);
const int maxlen = 80;
int len = normalised.Length;
bool prevDash = false;
var sb = new StringBuilder(len);
char c;
for (int i = 0; i < len; i++)
{
c = normalised[i];
if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9'))
{
if (prevDash)
{
sb.Append('-');
prevDash = false;
}
sb.Append(c);
}
else if (c >= 'A' && c <= 'Z')
{
if (prevDash)
{
sb.Append('-');
prevDash = false;
}
// Tricky way to convert to lowercase
if (toLower)
sb.Append((char)(c | 32));
else
sb.Append(c);
}
else if (c == ' ' || c == ',' || c == '.' || c == '/' || c == '\\' || c == '-' || c == '_' || c == '=')
{
if (!prevDash && sb.Length > 0)
{
prevDash = true;
}
}
else
{
string swap = ConvertEdgeCases(c, toLower);
if (swap != null)
{
if (prevDash)
{
sb.Append('-');
prevDash = false;
}
sb.Append(swap);
}
}
if (sb.Length == maxlen)
break;
}
return sb.ToString();
}
static string ConvertEdgeCases(char c, bool toLower)
{
string swap = null;
switch (c)
{
case 'ı':
swap = "i";
break;
case 'ł':
swap = "l";
break;
case 'Ł':
swap = toLower ? "l" : "L";
break;
case 'đ':
swap = "d";
break;
case 'ß':
swap = "ss";
break;
case 'ø':
swap = "o";
break;
case 'Þ':
swap = "th";
break;
}
return swap;
}
}
关于更多的细节,单元测试,以及为什么Facebook的URL方案比堆栈溢出更聪明的解释,我在我的博客上有一个扩展版本。
我不熟悉Ruby on Rails,但以下是(未经测试的)PHP代码。如果您觉得有用的话,可以很快地将其转换为Ruby on Rails。
$sURL = "This is a title to convert to URL-format. It has 1 number in it!";
// To lower-case
$sURL = strtolower($sURL);
// Replace all non-word characters with spaces
$sURL = preg_replace("/\W+/", " ", $sURL);
// Remove trailing spaces (so we won't end with a separator)
$sURL = trim($sURL);
// Replace spaces with separators (hyphens)
$sURL = str_replace(" ", "-", $sURL);
echo $sURL;
// outputs: this-is-a-title-to-convert-to-url-format-it-has-1-number-in-it
我希望这能有所帮助。
stackoverflow的解决方案是伟大的,但现代浏览器(不包括IE,像往常一样)现在很好地处理utf8编码:
所以我升级了建议的解决方案:
public static string ToFriendlyUrl(string title, bool useUTF8Encoding = false)
{
...
else if (c >= 128)
{
int prevlen = sb.Length;
if (useUTF8Encoding )
{
sb.Append(HttpUtility.UrlEncode(c.ToString(CultureInfo.InvariantCulture),Encoding.UTF8));
}
else
{
sb.Append(RemapInternationalCharToAscii(c));
}
...
}
Pastebin的完整代码
编辑:下面是RemapInternationalCharToAscii方法的代码(在粘贴文件中没有)。
我将代码移植到TypeScript中。它可以很容易地适应JavaScript。
我添加了一个.contains方法到字符串原型,如果你的目标是最新的浏览器或ES6,你可以使用.includes代替。
if (!String.prototype.contains) {
String.prototype.contains = function (check) {
return this.indexOf(check, 0) !== -1;
};
}
declare interface String {
contains(check: string): boolean;
}
export function MakeUrlFriendly(title: string) {
if (title == null || title == '')
return '';
const maxlen = 80;
let len = title.length;
let prevdash = false;
let result = '';
let c: string;
let cc: number;
let remapInternationalCharToAscii = function (c: string) {
let s = c.toLowerCase();
if ("àåáâäãåą".contains(s)) {
return "a";
}
else if ("èéêëę".contains(s)) {
return "e";
}
else if ("ìíîïı".contains(s)) {
return "i";
}
else if ("òóôõöøőð".contains(s)) {
return "o";
}
else if ("ùúûüŭů".contains(s)) {
return "u";
}
else if ("çćčĉ".contains(s)) {
return "c";
}
else if ("żźž".contains(s)) {
return "z";
}
else if ("śşšŝ".contains(s)) {
return "s";
}
else if ("ñń".contains(s)) {
return "n";
}
else if ("ýÿ".contains(s)) {
return "y";
}
else if ("ğĝ".contains(s)) {
return "g";
}
else if (c == 'ř') {
return "r";
}
else if (c == 'ł') {
return "l";
}
else if (c == 'đ') {
return "d";
}
else if (c == 'ß') {
return "ss";
}
else if (c == 'Þ') {
return "th";
}
else if (c == 'ĥ') {
return "h";
}
else if (c == 'ĵ') {
return "j";
}
else {
return "";
}
};
for (let i = 0; i < len; i++) {
c = title[i];
cc = c.charCodeAt(0);
if ((cc >= 97 /* a */ && cc <= 122 /* z */) || (cc >= 48 /* 0 */ && cc <= 57 /* 9 */)) {
result += c;
prevdash = false;
}
else if ((cc >= 65 && cc <= 90 /* A - Z */)) {
result += c.toLowerCase();
prevdash = false;
}
else if (c == ' ' || c == ',' || c == '.' || c == '/' || c == '\\' || c == '-' || c == '_' || c == '=') {
if (!prevdash && result.length > 0) {
result += '-';
prevdash = true;
}
}
else if (cc >= 128) {
let prevlen = result.length;
result += remapInternationalCharToAscii(c);
if (prevlen != result.length) prevdash = false;
}
if (i == maxlen) break;
}
if (prevdash)
return result.substring(0, result.length - 1);
else
return result;
}