使用 PHP 检查字符串是否包含数组中单词的任何实例

Question

我有一个简单的表格，需要额外的验证。我有一系列禁用词，如果存在，则表单提交失败。

如果输入中的“唯一单词”被禁止，我就可以让它工作。但是，如果它包含正常单词和禁用单词，则表单提交将通过。 我确实知道禁用词数据库工作正常，因为我有测试代码来输出所有这些词

只有当禁用术语是其中唯一的单词/字符串时，这才有效。

// array of banned words to filter; comes from DB
$disallowed_terms = Array();

$disallowed = $ww_mysqli->prepare("SELECT * FROM nl_filters");
$disallowed->bind_param('s', $Filter);
$disallowed->execute();

$s_result = $disallowed->get_result();

// check each input for banned words
while ($row = $s_result->fetch_assoc()) {
     $disallowed_terms[] = $row;

     // only wrote this for $sprequests for testing
     // strpos() doesn't seem to the right method here
     $sprequests_check = strpos($sprequests,$disallowed);

     if (in_array($sprequests_check,$row) !== false) {
        // adding anything to $reasons will cause submission to fail
         $reasons .= '|error';
      }
      if (in_array($theirname,$row) !== false) {
         $reasons .= '|error';
      }
      if (in_array($email,$row) !== false) {
         $reasons .= '|error';
      }
      if (in_array($phone,$row) !== false) {
         $reasons .= '|error';
      }
}

当前禁用词语列表是

这里

Answer 1

我们可以通过首先从输入中删除任何特殊字符并将其替换为空格，然后使用explode将字符串拆分到数组中来检查每个术语。

我简化了示例的代码，因此 $disallowed_terms 是一个静态数组，输入也是一个静态数组。请随意修改代码以匹配您的项目。

我在整个代码中留下了注释来解释发生了什么，但如果我错过了什么，请告诉我:)。请参阅下面的代码：

<?php
// Example disallowed terms, you would get these from the database
$disallowed_terms = [
    "bad",
    "evil",
    "crazy"
];

//example inputs from the user
$inputs = [
    "I like bad   things",
    "I like good things",
    "I like ok things",
    "I like evil, things",
    "  I like-crazy.things ",
];

$disallowed_terms_pattern = create_disallowed_terms_regex($disallowed_terms); // get the regex that will be used
// echo $disallowed_terms_pattern; // Outputs: /(bad|evil|crazy)/

// Test each input from user and echo the result
foreach ($inputs as $input){

    if(contains_disallowed_term($input,$disallowed_terms_pattern)){ // call function to check if input contains disallowed term
       // disallowed term found
        echo "NOT GOOD -".$input."<br>";
    }else{
        // disallowed term NOT found
        echo "OK -". $input."<br>";
    }
}

/* SAMPLE OUTPUT:
    NOT GOOD -I like bad things
    OK -I like good things
    OK -I like ok things
    NOT GOOD -I like evil, things
    NOT GOOD - I like-crazy.things
*/

// create regex pattern string that will contain all the disallowed terms eg. Outputs: /(bad|evil|crazy)/
function create_disallowed_terms_regex($disallowed_terms){
    $regex = '/(';
    foreach ($disallowed_terms as $term){
        $regex.=$term.'|';
    }

    $regex = rtrim($regex,'|'); // remove | from end of string

    $regex .= ')/';

    return $regex;
}

function contains_disallowed_term($input,$disallowed_terms_pattern){

    // Replace all special characters with spaces, this stops inputs like i'am-not-crazy;) from getting passed the regex
    $input = preg_replace('/[^\w\s]/', ' ', $input);

    $input_terms = explode(" ", $input); // explode the input string into an array using spaces as a seperator

    foreach ($input_terms as $term){ // go over each term in the input
        if(preg_match($disallowed_terms_pattern, $term)){
            return true; // if it matches a word in disallowed list return true;
        }
    }
    
    //term didn't match disallowed term, return false
    return false;
}

?>

此解决方案的明显限制是它无法检测像“cr*zy”这样的单词，因为它删除了 * 并将其替换为空格。另一方面，它会检测到像这样的“.:thats-crazy:.”这样的“crazy”一词。

如果某些不允许的单词包含特殊字符，则解决方案可能也需要修改。由于 create_disallowed_terms_regex() 函数可能会中断，并且永远不会检测到具有特殊字符的单词，因为解决方案会从输入中删除特殊字符。这两个问题都可以通过微小的改变来缓解。