如何在我的网站中将 og:image 显示为链接的缩略图

Question

我有一个输入字段，用户可以在其中输入URL（网站链接，视频链接，谷歌地图链接或任何其他链接）

<input type="url" name="user_url">

我想将这些链接的缩略图和描述显示为预览而不是简单的 URL。由于我想使用 og：image meta 来获取缩略图，但我不知道如何存档它以及我应该使用什么技术，或者是否有任何 API 来获取它。谢谢

Answer 1

您可以使用下面的代码。只需使用POST请求将变量传递给get_url_data.php url作为响应，您将获得image，description和title。

get_url_data.php

<?php
if(isset($_POST['url']) && !empty($_POST['url']) && filter_var($_POST['url'], FILTER_VALIDATE_URL)) {
    //gets the HTML data
    $source = getData($_POST['url']);
    // DOM document Creation
    $doc = new DOMDocument;
    libxml_use_internal_errors(true);
    $doc->loadHTML($source);
    libxml_clear_errors();
    // DOM XPath Creation
    $xpath = new DOMXPath($doc);
    // Gets title
    $title = $xpath->query('//title')->item(0)->textContent;
    if(empty($title))
        $title = "No title found";
    // Gets all Open Graph images
    $events = $xpath->query('//meta[@property="og:image"]/@content');
    $image = "";
    for($i = 0; $i < ($events->length); $i++) {
        $event = $events->item($i);
        $des = $xpath->evaluate('//meta[@property="og:image"]/@content', $event);
        if ($des->length > 0) {
            $image = $des->item(0)->value;
            break;
        }
    }
    if(empty($image))
        $image = "image-not-found.gif";
    // Gets all Open Graph descriptions
    $events = $xpath->query('//meta[@property="og:description"]/@content');
    $description = "";
    for($i = 0; $i < ($events->length); $i++) {
        $event = $events->item($i);
        $des = $xpath->evaluate('//meta[@property="og:description"]/@content', $event);
        if ($des->length > 0) {
            $description = $des->item(0)->value;
            break;
        }
    }
    if(empty($description))
        $description = "-- No description found --";
    //output
    $data = array('title' => $title, 'image' => $image, 'description' => $description);
    echo json_encode($data);
}
//fetches HTML data from a URL
function getData($url)
{   
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
    curl_setopt($ch, CURLOPT_HEADER,0);
    curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7 GTB6 (.NET CLR 3.0.4506.2152)");
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION,1);
    curl_setopt($ch, CURLOPT_URL, $url);    
    $content = curl_exec($ch);
    curl_close($ch);
    return $content;
}

您还可以查看我的git存储库以获取更多详细信息。

https://github.com/khmahbubul/get-thumbnail