Question

所以我在这里为PHP写了这个脚本，因为我找不到任何关于它的东西。这样做是为了获取Facebook的缩略图图像代码并显示它。我的问题是在显示它们之前测试这些图像是否确实存在，因为Facebook默认为问号图像，我无法测试损坏的链接。如果我所引用的问号不存在，我将如何唯一地识别Facebook返回的问号图像？

//define our test subject
$testvar = "[[490550790968952]][[490550800968951]][[490550807635617]]  
[[490550820968949]][[490550837635614]][[490550847635613]]  
[[490550857635612]][[490550867635611]][[490550877635610]]  
[[490550884302276]][[490550894302275]][[490550900968941]]  
[[490550914302273]][[490550924302272]][[490550937635604]]  
[[490550947635603]][[490550954302269]][[490550967635601]]";

//this one is a broken link and generates the question mark, remove this line to test the above code
$testvar = "[[171108522930776]]";

//convert new lines to <br>
$testvar = nl2br($testvar);

//replace all numbers with links
$numfilter = "/([0-9]){1,}/"; //match all number blocks without brackets
$testvar = preg_replace($numfilter, "<img src='https://graph.facebook.com/\\0/picture'>", $testvar);

//strip the brackets
$stripbrackets = array("[[","]]");
$testvar = str_replace($stripbrackets,"",$testvar);

//echo a div with the output, setting font-size:0 so the <br> tags don't create vertical spacing between new lines
echo "<div style='font-size:0px; line-height:0px;'>";
echo $testvar;
echo "</div>";

?>

Answer 1

如果您没有获得重定向，则Facebook会返回is_silhouette字段。看一下这个结果：https://graph.facebook.com?fields=name,picture&ids=490550790968952,171108522930776

如果你使用cURL进入PHP，然后json_decode()这个结果，你将能够遍历它并测试每个id，看看它是否是Facebook的未定义图像之一

Facebook聊天打开图形图像代码解析

1 个答案: