检查 URL 是视频 URL 还是 PHOTO URL

Question

我有一个文本视图，用户应该在其中输入一个 url。首先，我正在检查 URL 的有效性。确认有效性后，我需要检查它是视频 url 还是照片 url。我有两个数组，包含所有可能的视频（MP4、MOV 等）和照片（JPG、PNG）文件格式，如果 url 包含这两个数组中的任何元素，我会收到一条适当的消息。

这是一个示例 instagram 视频链接。 例如：https://www.instagram.com/p/B-PilcbFy2w/

以下链接是有效的视频链接，但不包含任何视频文件格式，例如（MOV、MP4 等）。如何验证此类链接？

我知道正则表达式的概念来验证这些事情，但为此我必须实现一堆 IF 语句，这不是一种有效的方法。示例视频链接只是一个示例。我需要验证所有类型的视频链接，无论它们来自社交媒体平台还是其他。非常感谢您帮助重新评分。

这是我的示例代码..

@IBOutlet weak var textVW: UITextView!

@IBAction func validateButton(_ sender: UIButton) {


    let userInputURL = URL(string: textVW.text)

    if userInputURL != nil && userInputURL?.scheme != nil && userInputURL?.host != nil {
        //  - a scheme (like http://)
        //  - a host (like stackoverflow.com)

        print("Valid URL..")

        // Now checking url type, if its a video or image url..
        checkURLType(inputURL: userInputURL!)

    }

    else {
        print("Invalid URL..")
    }
}

func checkURLType(inputURL : URL) {

    // Most commom image types..
    let imageExtensions = ["png", "jpg", "gif", "tif"]

    // Most cmmon video types..
    let videoExtensions = ["WEBM", "MPG", "MPEG", "MPE", "MP4", "M4P", "M4V", "AVI", "WMV", "MOV"]

    let url: URL? = NSURL(fileURLWithPath: inputURL.path) as URL
    let pathExtention = url?.pathExtension

    if imageExtensions.contains(pathExtention!)
        {
            print("Image URL: \(String(describing: url))")

        }

    else if videoExtensions.contains(pathExtention!)
        {
             print("Video URL: \(String(describing: url))")
        }

        else
        {
             print("Does Not Exist: \(String(describing: url))")
        }


}

Answer 1

简短的回答，正如您已经发现的那样，您不能以可靠的方式使用 URL 来确定返回的 ressource。

长答案：URL 中的“扩展名”根本没有意义。将 if 视为对客户端的提示，但 Web 服务器可能会做它想做的事。 以https://www.acme.com 为例：根本没有文件扩展名，并且根据其配置，Web 服务器决定返回什么资源。通常，这将是一个 HTML 文档，例如“index.html”之类的。 更重要的是，https://www.acme.com/index.php 有一个 php 扩展名，但 Web 服务器通常会返回一个 HTML 文档，而不是 PHP 脚本。

获取信息的唯一方法是检查URLResponse 的mimeType 属性。

如果你只对标题数据感兴趣（在下载所有内容之前），你应该检查这个答案：Get HTTP header fields only on iPhone

Answer 2

Instagram 不包含您要查找的文件格式。 相反，您可以使用一个简单的技巧来确认链接是否代表 视频或照片。 这就是您提供的 Instagram 链接： https://www.instagram.com/p/B-PilcbFy2w/

当我们在 Instagram 帖子的链接末尾添加 ?__a=1 时，我们会得到如下内容：

{"graphql":{"shortcode_media":{"__typename":"GraphImage",
"id":"2275681914071665931",
"shortcode":"B-U2KTOBc0L",
"dimensions":{"height":1080,
"width":1080},
"gating_info":null,
"fact_check_overall_rating":null,
"fact_check_information":null,
"sensitivity_friction_info":null,
"media_preview":"ACoq2XcL+PbvQ24KW6kDIHr7VDbKW/eN15C+w9fx/lUm/PIb/wAdNIb0GfaApxtYj1Cn/CnQzGXqrLgZ5GPwpd5/vf8AjpoLn+9/46aYiaimIc98/gR/On0ARxD92o6fKP5U3Jx/H+lMtX3QqRyQMEdORxT9vsf++v8A69A2Lk/7f5Cjn/b/ACH6UbT6H/vr/wCvRtPof++qBDkyeTu/4Fj+lPqNF29AR9Tnp0qSgDMg/djcw+R+cdSD/eq4EDjICFT0PNSOMg1nQsVn2g4BA4HT8qnbQrfUv7D3C/r/AIUeX/srn8f8KmoqiSJUA6gA9sVJS0UAf//Z",
"display_url":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-15/e35/91790764_531125317547482_7904098713138015435_n.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_cat=110&_nc_ohc=X8nt1F5JsVAAX_cmJQe&oh=a608b3496a9bef59e9d372ce339e496f&oe=5EB63B42",
"display_resources":[{"src":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-15/sh0.08/e35/s640x640/91790764_531125317547482_7904098713138015435_n.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_cat=110&_nc_ohc=X8nt1F5JsVAAX_cmJQe&oh=04905a5d307b7d70d9912630b68bced5&oe=5EB648A5",
"config_width":640,
"config_height":640},
{"src":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-15/sh0.08/e35/s750x750/91790764_531125317547482_7904098713138015435_n.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_cat=110&_nc_ohc=X8nt1F5JsVAAX_cmJQe&oh=e5efae91c8fef2f14c4abbf5bf50a709&oe=5EB6B025",
"config_width":750,
"config_height":750},
{"src":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-15/e35/91790764_531125317547482_7904098713138015435_n.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_cat=110&_nc_ohc=X8nt1F5JsVAAX_cmJQe&oh=a608b3496a9bef59e9d372ce339e496f&oe=5EB63B42",
"config_width":1080,
"config_height":1080}],
"accessibility_caption":"Photo by \ud83c\udde7\ud83c\udded Dallaspresso on March 29,
 2020. Image may contain: text",
"is_video":false,
"tracking_token":"eyJ2ZXJzaW9uIjo1LCJwYXlsb2FkIjp7ImlzX2FuYWx5dGljc190cmFja2VkIjp0cnVlLCJ1dWlkIjoiMmRmOGE3M2Q1OTljNDA0YWI1OTBiYzEwMjRjMDEzNDIyMjc1NjgxOTE0MDcxNjY1OTMxIn0sInNpZ25hdHVyZSI6IiJ9",
"edge_media_to_tagged_user":{"edges":[]},
"edge_media_to_caption":{"edges":[{"node":{"text":"\u062f\u0644\u0627\u0633\u0628\u0631\u064a\u0633\u0648.. \u062f\u0644\u0644 \u062d\u0648\u0627\u0633\u0643\n.\n\n#Dallaspresso\n#nespresso #photography #Bahrain #\u0627\u0644\u0628\u062d\u0631\u064a\u0646 #\u0642\u0647\u0648\u0629 #\u0627\u0644\u0633\u0639\u0648\u062f\u064a\u0629 #\u0627\u0644\u0643\u0648\u064a\u062a #\u0627\u0644\u0639\u0631\u0627\u0642  #\u0645\u0635\u0631 #\u0639\u0645\u0627\u0646 #\u062f\u0644\u0627\u0633\u0628\u0631\u064a\u0633\u0648 #\u0639\u0645\u0627\u0646 #\u0645\u0646\u0634\u0646 #\u0646\u0633\u0628\u0631\u064a\u0633\u0648 #\u0627\u0644\u062d\u0628 #\u0643\u0628\u0633\u0648\u0644\u0627\u062a_\u0642\u0647\u0648\u0647 #\u0643\u0628\u0633\u0648\u0644\u0627\u062a_\u0642\u0647\u0648\u0629"}}]},
"caption_is_edited":false,
"has_ranked_comments":false,
"edge_media_to_parent_comment":{"count":2,
"page_info":{"has_next_page":false,
"end_cursor":null},
"edges":[{"node":{"id":"17873033503626679",
"text":"\u0627\u0644\u0635\u0631\u0627\u062d\u0647 \u0645\u0646\u062a\u062c\u0627\u062a \u062e\u064a\u0627\u0644\u064a\u0647 \u0627\u0646\u0627 \u0632\u0628\u0648\u0646 \u062f\u0627\u0645 \u0648\u064a\u0627\u0627\u0627\u0643\u0645 \u0645\u0646 \u0627\u0648\u0644 \u0645\u0627\u0646\u0632\u0644\u062a\u0648\u0646 \u0627\u0644\u0645\u0646\u062a\u062c\u0627\u062a \u0643\u0644 \u0645\u0646\u062a\u062c \u0627\u0644\u064a\u0647 \u0645\u0630\u0627\u0642 \u0627\u0631\u0648\u0639 \u0645\u0646 \u0627\u0644\u062b\u0627\u0646\u064a \u0648\u0646\u062a\u0638\u0631 \u0645\u0646\u0643\u0645 \u0627\u0644\u0645\u0632\u064a\u062f\u2764\ufe0f",
"created_at":1585548401,
"did_report_as_spam":false,
"owner":{"id":"6983355053",
"is_verified":false,
"profile_pic_url":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-19/s150x150/62439219_378925886148443_2705326417154932736_n.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_ohc=_b_clBY3nsgAX9hxHqp&oh=69c82b500e15d3e3f926e0057bbb1a93&oe=5EB84221",
"username":"hassanjasaim"},
"viewer_has_liked":false,
"edge_liked_by":{"count":1},
"is_restricted_pending":false,
"edge_threaded_comments":{"count":0,
"page_info":{"has_next_page":false,
"end_cursor":null},
"edges":[]}}},
{"node":{"id":"18103267534188420",
"text":"\u0627\u0646\u0627 \u0627\u0648\u0644 \u0645\u0631\u0629 \u0627\u062a\u0639\u0627\u0645\u0644 \u0645\u0639\u0627\u0643\u0645.. \u0627\u0644\u0635\u0631\u0627\u062d\u0629 \u0641\u0627\u062c\u0626\u062a\u0648\u0646\u064a \u0628\u0627\u0644\u0633\u0631\u0639\u0629 \u0648\u062e\u062f\u0645\u062a\u0643\u0645 \u0627\u0644\u0631\u0627\u0626\u0639\u0629.. \u062e\u0644\u0627\u0644 \u0623\u0642\u0644 \u0645\u0646 \u0661\u0662 \u0633\u0627\u0639\u0629 \u0648\u0635\u0644 \u0644\u064a \u0627\u0644\u0637\u0644\u0628.. \u0648\u0627\u0646 \u0634\u0627\u0621 \u0627\u0644\u0644\u0647 \u0628\u064a\u0643\u0648\u0646 \u062a\u0639\u0627\u0645\u0644\u0646\u0627 \u062f\u0627\u0626\u0645 \u0645\u0639\u0627\u0643\u0645.. \u0634\u0627\u0643\u0631\u064a\u0646 \u0644\u0643\u0645 \u0627\u0647\u062a\u0645\u0627\u0645\u0643\u0645 \u0628\u0631\u0636\u0627 \u0627\u0644\u0632\u0628\u0627\u0626\u0646.. \u0627\u0644\u0644\u0647 \u064a\u0648\u0641\u0642\u0643\u0645\ud83d\udc96",
"created_at":1585658629,
"did_report_as_spam":false,
"owner":{"id":"266197895",
"is_verified":false,
"profile_pic_url":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-19/10727387_322891407903875_1650333521_a.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_ohc=-r1CI1ZAVwgAX9XRWAW&oh=a58ed12c2f770c9f790bb77d6ff3038d&oe=5EB9954D",
"username":"amooor440"},
"viewer_has_liked":false,
"edge_liked_by":{"count":0},
"is_restricted_pending":false,
"edge_threaded_comments":{"count":0,
"page_info":{"has_next_page":false,
"end_cursor":null},
"edges":[]}}}]},
"edge_media_to_hoisted_comment":{"edges":[]},
"edge_media_preview_comment":{"count":2,
"edges":[{"node":{"id":"17873033503626679",
"text":"\u0627\u0644\u0635\u0631\u0627\u062d\u0647 \u0645\u0646\u062a\u062c\u0627\u062a \u062e\u064a\u0627\u0644\u064a\u0647 \u0627\u0646\u0627 \u0632\u0628\u0648\u0646 \u062f\u0627\u0645 \u0648\u064a\u0627\u0627\u0627\u0643\u0645 \u0645\u0646 \u0627\u0648\u0644 \u0645\u0627\u0646\u0632\u0644\u062a\u0648\u0646 \u0627\u0644\u0645\u0646\u062a\u062c\u0627\u062a \u0643\u0644 \u0645\u0646\u062a\u062c \u0627\u0644\u064a\u0647 \u0645\u0630\u0627\u0642 \u0627\u0631\u0648\u0639 \u0645\u0646 \u0627\u0644\u062b\u0627\u0646\u064a \u0648\u0646\u062a\u0638\u0631 \u0645\u0646\u0643\u0645 \u0627\u0644\u0645\u0632\u064a\u062f\u2764\ufe0f",
"created_at":1585548401,
"did_report_as_spam":false,
"owner":{"id":"6983355053",
"is_verified":false,
"profile_pic_url":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-19/s150x150/62439219_378925886148443_2705326417154932736_n.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_ohc=_b_clBY3nsgAX9hxHqp&oh=69c82b500e15d3e3f926e0057bbb1a93&oe=5EB84221",
"username":"hassanjasaim"},
"viewer_has_liked":false,
"edge_liked_by":{"count":1},
"is_restricted_pending":false}},
{"node":{"id":"18103267534188420",
"text":"\u0627\u0646\u0627 \u0627\u0648\u0644 \u0645\u0631\u0629 \u0627\u062a\u0639\u0627\u0645\u0644 \u0645\u0639\u0627\u0643\u0645.. \u0627\u0644\u0635\u0631\u0627\u062d\u0629 \u0641\u0627\u062c\u0626\u062a\u0648\u0646\u064a \u0628\u0627\u0644\u0633\u0631\u0639\u0629 \u0648\u062e\u062f\u0645\u062a\u0643\u0645 \u0627\u0644\u0631\u0627\u0626\u0639\u0629.. \u062e\u0644\u0627\u0644 \u0623\u0642\u0644 \u0645\u0646 \u0661\u0662 \u0633\u0627\u0639\u0629 \u0648\u0635\u0644 \u0644\u064a \u0627\u0644\u0637\u0644\u0628.. \u0648\u0627\u0646 \u0634\u0627\u0621 \u0627\u0644\u0644\u0647 \u0628\u064a\u0643\u0648\u0646 \u062a\u0639\u0627\u0645\u0644\u0646\u0627 \u062f\u0627\u0626\u0645 \u0645\u0639\u0627\u0643\u0645.. \u0634\u0627\u0643\u0631\u064a\u0646 \u0644\u0643\u0645 \u0627\u0647\u062a\u0645\u0627\u0645\u0643\u0645 \u0628\u0631\u0636\u0627 \u0627\u0644\u0632\u0628\u0627\u0626\u0646.. \u0627\u0644\u0644\u0647 \u064a\u0648\u0641\u0642\u0643\u0645\ud83d\udc96",
"created_at":1585658629,
"did_report_as_spam":false,
"owner":{"id":"266197895",
"is_verified":false,
"profile_pic_url":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-19/10727387_322891407903875_1650333521_a.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_ohc=-r1CI1ZAVwgAX9XRWAW&oh=a58ed12c2f770c9f790bb77d6ff3038d&oe=5EB9954D",
"username":"amooor440"},
"viewer_has_liked":false,
"edge_liked_by":{"count":0},
"is_restricted_pending":false}}]},
"comments_disabled":false,
"commenting_disabled_for_viewer":false,
"taken_at_timestamp":1585502445,
"edge_media_preview_like":{"count":27,
"edges":[]},
"edge_media_to_sponsor_user":{"edges":[]},
"location":null,
"viewer_has_liked":false,
"viewer_has_saved":false,
"viewer_has_saved_to_collection":false,
"viewer_in_photo_of_you":false,
"viewer_can_reshare":true,
"owner":{"id":"8634941354",
"is_verified":false,
"profile_pic_url":"https://instagram.fbah6-1.fna.fbcdn.net/v/t51.2885-19/s150x150/50091870_301664920553287_8948101179057897472_n.jpg?_nc_ht=instagram.fbah6-1.fna.fbcdn.net&_nc_ohc=gOUeaMbAyA8AX8wKTVK&oh=f2b7e5c953d8b19fa5aaf787019ecc56&oe=5EB97A7A",
"username":"dallaspressobh",
"blocked_by_viewer":false,
"restricted_by_viewer":null,
"followed_by_viewer":false,
"full_name":"\ud83c\udde7\ud83c\udded Dallaspresso",
"has_blocked_viewer":false,
"is_private":false,
"is_unpublished":false,
"requested_by_viewer":false,
"edge_owner_to_timeline_media":{"count":155}},
"is_ad":false,
"edge_web_media_to_related_media":{"edges":[]},
"edge_related_profiles":{"edges":[]}}}}

您可以轻松搜索元素“is_video”，如果为false，则帖子为图片，否则为视频。 如果有帮助，请标记为已回答。