Question

如何从字符串中删除HTML标记，以便输出干净的文本？

let str = string.stringByReplacingOccurrencesOfString("<[^>]+>", withString: "", options: .RegularExpressionSearch, range: nil)
print(str)

Answer 1

嗯，我尝试了你的功能，它只是一个小例子：

var string = "<!DOCTYPE html> <html> <body> <h1>My First Heading</h1> <p>My first paragraph.</p> </body> </html>"
let str = string.stringByReplacingOccurrencesOfString("<[^>]+>", withString: "", options: .RegularExpressionSearch, range: nil)
print(str)

//output "  My First Heading My first paragraph. "

你能举个问题的例子吗？

Answer 2

由于HTML不是regular language（HTML是context-free语言），因此您无法使用正则表达式。请参阅：Using regular expressions to parse HTML: why not?

我会考虑改用NSAttributedString。

let htmlString = "LCD Soundsystem was the musical project of producer <a href='http://www.last.fm/music/James+Murphy' class='bbcode_artist'>James Murphy</a>, co-founder of <a href='http://www.last.fm/tag/dance-punk' class='bbcode_tag' rel='tag'>dance-punk</a> label <a href='http://www.last.fm/label/DFA' class='bbcode_label'>DFA</a> Records. Formed in 2001 in New York City, New York, United States, the music of LCD Soundsystem can also be described as a mix of <a href='http://www.last.fm/tag/alternative%20dance' class='bbcode_tag' rel='tag'>alternative dance</a> and <a href='http://www.last.fm/tag/post%20punk' class='bbcode_tag' rel='tag'>post punk</a>, along with elements of <a href='http://www.last.fm/tag/disco' class='bbcode_tag' rel='tag'>disco</a> and other styles. <br />"    
let htmlStringData = htmlString.dataUsingEncoding(NSUTF8StringEncoding)!
let options: [String: AnyObject] = [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: NSUTF8StringEncoding]
let attributedHTMLString = try! NSAttributedString(data: htmlStringData, options: options, documentAttributes: nil)
let string = attributedHTMLString.string

或者，正如评论中的Irshad Mohamed所做的那样：

let attributed = try NSAttributedString(data: htmlString.data(using: .unicode)!, options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType], documentAttributes: nil)
print(attributed.string)

Answer 3

我使用以下扩展程序删除特定的HTML元素：

extension String {
    func deleteHTMLTag(tag:String) -> String {
        return self.stringByReplacingOccurrencesOfString("(?i)</?\(tag)\\b[^<]*>", withString: "", options: .RegularExpressionSearch, range: nil)
    }

    func deleteHTMLTags(tags:[String]) -> String {
        var mutableString = self
        for tag in tags {
            mutableString = mutableString.deleteHTMLTag(tag)
        }
        return mutableString
    }
}

这样就可以只从字符串中删除<a>标记，例如：

let string = "my html <a href="">link text</a>"
let withoutHTMLString = string.deleteHTMLTag("a") // Will be "my  html link text"

Answer 4

穆罕默德解决方案，但作为Swift 4中的String扩展。

extension String {

    func stripOutHtml() -> String? {
        do {
            guard let data = self.data(using: .unicode) else {
                return nil
            }
            let attributed = try NSAttributedString(data: data, options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding: String.Encoding.utf8.rawValue], documentAttributes: nil)
            return attributed.string
        } catch {
            return nil
        }
    }
}

Answer 5

斯普利特4：

extension String {
    func deleteHTMLTag(tag:String) -> String {
        return self.replacingOccurrences(of: "(?i)</?\(tag)\\b[^<]*>", with: "", options: .regularExpression, range: nil)
    }

    func deleteHTMLTags(tags:[String]) -> String {
        var mutableString = self
        for tag in tags {
            mutableString = mutableString.deleteHTMLTag(tag: tag)
        }
        return mutableString
    }
}

Answer 6

已为Swift 4更新。警卫让htmlStringData = htmlString.data（使用：.unicode），否则{fatalError（）}

    let options: [NSAttributedString.DocumentReadingOptionKey: Any] = [
        .documentType: NSAttributedString.DocumentType.html
        .characterEncoding: String.Encoding.unicode.rawValue
    ]

    let attributedHTMLString = try! NSAttributedString(data: htmlStringData, options: options, documentAttributes: nil)
    let string = attributedHTMLString.string

Answer 7

@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)

快乐编码

Answer 8

与使用NSAttributedString HTML转换相比，我更喜欢使用正则表达式，请注意这非常耗时，并且也需要在主线程上运行。这里的更多信息：https://developer.apple.com/documentation/foundation/nsattributedstring/1524613-initwithdata

这对我来说很成功，首先我删除所有CSS内联样式，然后删除所有HTML标记。可能不像NSAttributedString选项那样可靠，但是对于我的情况来说要快得多。

extension String {
    func withoutHtmlTags() -> String {
        let str = self.replacingOccurrences(of: "<style>[^>]+</style>", with: "", options: .regularExpression, range: nil)
        return str.replacingOccurrences(of: "<[^>]+>", with: "", options: .regularExpression, range: nil)
    }
}

Answer 9

Swift 5

extension String {
    public func trimHTMLTags() -> String? {
        guard let htmlStringData = self.data(using: String.Encoding.utf8) else {
            return nil
        }
    
        let options: [NSAttributedString.DocumentReadingOptionKey : Any] = [
            .documentType: NSAttributedString.DocumentType.html,
            .characterEncoding: String.Encoding.utf8.rawValue
        ]
    
        let attributedString = try? NSAttributedString(data: htmlStringData, options: options, documentAttributes: nil)
        return attributedString?.string
    }
}

使用：

let  str = "my html <a href='https://www.google.com'>link text</a>"

print(str.trimHTMLTags() ?? "--") //"my html link text"

从字符串中删除HTML标记

9 个答案: