为什么当我在 HTML 中调用我的 Javascript 函数时它不能运行/工作

Why does my Javascript function not run/work when I call it in HTML?

本文关键字：函数 不能 运行 工作 Javascript 我的 HTML 调用 为什么      更新时间：2023-09-26

所以我尝试了许多调用函数本身的方法。我对PHP/Javascript相当陌生，所以我正在尝试学习它。

我创建了一个函数来检查是否选中了某个复选框。我希望该函数做的是在选中复选框时将页面重定向到另一个页面，如果未选中，则显示警报框。

我

通过javascript函数传递的变量来自我的PHP代码，所以我认为我的问题可能与两种语言如何相互作用有关。

这是我的代码。我从SQL数据库中获取各种变量并将其存储在PHP变量中。我在 PHP 代码中的注释行之后调用该函数：

function checkReceived(received, profEmail){
	if (received == checked){
		window.location.assign('https://someurl.php?email=' + profEmail');
	} else{
		alert("LOL HOW ABOUT NO");
	}
}
<?php
	//This loop populates the ticket display using the records in the database
	while($recordSet->EOF == false){
		$ticketNumber = $recordSet->Fields['TicketNumber'];
		$dateSubmitted = $recordSet->Fields['DateSubmitted'];
		$department = $recordSet->Fields['Department'];
		$courseNo = $recordSet->Fields['CourseNumber'];
		$instructorName = $recordSet->Fields['InstructorName'];
		$received = ($recordSet->Fields['Received']) ? "checked" : "unchecked";
		$sendReminder = ($recordSet->Fields['SendReminder']) ? "checked" : "unchecked";
		$email = $recordSet->Fields['Email'];
		$CC = $recordSet->Fields['CC'];
		$strHTML  = "<tr><td>$dateSubmitted</td>";
		$strHTML .= "<td>$department</td>";
		$strHTML .= "<td>$courseNo</td>";
		$strHTML .= "<td style='word-break: break-all'>$instructorName</td>";
		$strHTML .= "<td align='center'> <input type='checkbox' ".$received." class='receivedCheckbox' onchange='checkboxClicked('"Received'", ".$ticketNumber.")'/> </td>";
		$strHTML .= "<td align='center'> <input type='checkbox' ".$sendReminder." class='sendReminderCheckbox' onchange='checkboxClicked('"SendReminder'", ".$ticketNumber.")' data-email='".$email."'/> </td>";
		//$strHTML .= "<td style='word-break: break-all;' align='center'> <a href='javascript:checkReceived($received, $email)'>".$email."</a></td>";
		$strHTML .= "<td><button id='emailButton' onclick='checkReceived($received, $email)'>".$email."</button></td>";
		$strHTML .= "<td align='center'> <button onclick='"window.open('https://someurl.php?ticketNumber=".$ticketNumber."')'">Print</button> </td>";
		$strHTML .= "</tr>";
		echo $strHTML;
		$recordSet->MoveNext;
	}
?>

根据要求，这是我$strHTML：

<td>Psychology</td>
<td>1000</td>
<td style='word-break: break-all'>Some Name</td>
<td align='center'> <input type='checkbox' checked class='receivedCheckbox' onchange='checkboxClicked("Received", 31)'/> </td>
<td align='center'> <input type='checkbox' unchecked class='sendReminderCheckbox' onchange='checkboxClicked("SendReminder", 31)' data-email='email@email.ca'/></td>
<td><button id='emailButton' onclick='checkReceived(checked, email@email.ca)'>email@email.ca</button></td>
<td align='center'> <button onclick="window.open('https://someurl.php?ticketNumber=31')">Print</button> </td>
</tr>

在javascript中，不要写 

if (received == checked){

但 

if (received == "checked"){

您想将变量received与字符串"checked"进行比较。通过 PHP，received变量接收值"checked"或"unchecked" 

$received = ($recordSet->Fields['Received']) ? "checked" : "unchecked";

然后通过javascript函数调用将其转换为HTML。javascript 函数必须使用类似字符串调用

checkReceived("string", "string") ，

所以在 PHP 中它变成了

echo "checkReceived('"string'", '"string'")";

和 PHP 变量

echo "checkReceived('"$var1'", '"$var2'")";

在您的代码中，它变为：

$strHTML .= "<td><button id='emailButton' onclick='checkReceived('"$received'", '"$email'")'>$email</button></td>";

要查看是否调用了函数 checkReceived()，请插入 console.log() 语句并查看浏览器的调试器 JavaScript 控制台。

checkReceived(received, profEmail){
    console.log(received, profEmail);
}

问题是在从 php 连接 html 时。调用函数时应使用转义序列（例如 onchange='"checkboxClicked('Received', ".$ticketNumber.")'"）

$strHTML  = "<tr><td>$dateSubmitted</td>";
    $strHTML .= "<td>$department</td>";
    $strHTML .= "<td>$courseNo</td>";
    $strHTML .= "<td style='word-break: break-all'>$instructorName</td>";
    $strHTML .= "<td align='center'> <input type='checkbox' ".$received." class='receivedCheckbox' onchange='"checkboxClicked('Received', ".$ticketNumber.")'"/> </td>";
    $strHTML .= "<td align='center'> <input type='checkbox' ".$sendReminder." class='sendReminderCheckbox' onchange='"checkboxClicked('SendReminder', ".$ticketNumber.")'" data-email='".$email."'/> </td>";
    //$strHTML .= "<td style='word-break: break-all;' align='center'> <a href='javascript:checkReceived($received, $email)'>".$email."</a></td>";
    $strHTML .= "<td><button id='emailButton' onclick='"checkReceived('$received', '$email')'">".$email."</button></td>";
    $strHTML .= "<td align='center'> <button onclick='"window.open('https://someurl.php?ticketNumber=".$ticketNumber."')'">Print</button> </td>";
    $strHTML .= "</tr>";

在JavaScript函数中if(checked == "checked")带引号的函数

我正在用更好的解释从评论中扩展我的答案。

首先，在JS中，不要将变量与checked进行比较，而是与@PaulH提到的"checked"（即字符串）进行比较。

所以你的JS应该看起来像：

function checkReceived(received, profEmail){
    if (received == "checked"){
        window.location.assign('https://someurl.php?email=' + profEmail);
    } else{
        alert("LOL HOW ABOUT NO");
    }
}

现在对于 PHP，在第 $strHTML .= "<td><button id='emailButton' onclick='checkReceived($received, $email)'>".$email."</button></td>"; 行中，您没有将 $received 的输出包装在引号 （ " ） 中$email变量。这是必要的，因为它会打印 HTML，这将字符串传递给 JS 函数。所以你的PHP代码需要看起来像这样：

<?php
    //This loop populates the ticket display using the records in the database
    while($recordSet->EOF == false){
        $ticketNumber = $recordSet->Fields['TicketNumber'];
        $dateSubmitted = $recordSet->Fields['DateSubmitted'];
        $department = $recordSet->Fields['Department'];
        $courseNo = $recordSet->Fields['CourseNumber'];
        $instructorName = $recordSet->Fields['InstructorName'];
        $received = ($recordSet->Fields['Received']) ? "checked" : "unchecked";
        $sendReminder = ($recordSet->Fields['SendReminder']) ? "checked" : "unchecked";
        $email = $recordSet->Fields['Email'];
        $CC = $recordSet->Fields['CC'];

        $strHTML  = "<tr><td>$dateSubmitted</td>";
        $strHTML .= "<td>$department</td>";
        $strHTML .= "<td>$courseNo</td>";
        $strHTML .= "<td style='word-break: break-all'>$instructorName</td>";
        $strHTML .= "<td align='center'> <input type='checkbox' ".$received." class='receivedCheckbox' onchange='checkboxClicked('"Received'", ".$ticketNumber.")'/> </td>";
        $strHTML .= "<td align='center'> <input type='checkbox' ".$sendReminder." class='sendReminderCheckbox' onchange='checkboxClicked('"SendReminder'", ".$ticketNumber.")' data-email='".$email."'/> </td>";
        //$strHTML .= "<td style='word-break: break-all;' align='center'> <a href='javascript:checkReceived($received, $email)'>".$email."</a></td>";
        $strHTML .= "<td><button id='emailButton' onclick='checkReceived('"$received'", '"$email'")'>".$email."</button></td>";
        $strHTML .= "<td align='center'> <button onclick='"window.open('https://someurl.php?ticketNumber=".$ticketNumber."')'">Print</button> </td>";
        $strHTML .= "</tr>";
        echo $strHTML;
        $recordSet->MoveNext;
    }
?>

让我知道结果如何。

相关文章：