[英]How to pass PHP data to external JavaScript
I want to pass a variable, or rather a message, from my PHP file to my external JavaScript file. 我想将变量或消息从PHP文件传递到外部JavaScript文件。 I have looked at other answered questions and it seems like the PHP file is not really full PHP, it has some js codes in it.
我看了其他回答的问题,似乎PHP文件不是真正的完整PHP,它包含一些js代码。
I just want to pass a simple message so I can use alert()
in the external js to show the message. 我只想传递一条简单的消息,以便可以在外部js中使用
alert()
来显示消息。
Should I use JSON(which I do not know how)? 我应该使用JSON(我不知道如何)吗? Or is there a simpler way?
还是有更简单的方法? I am new to all these so perhaps a simple explanation with an answer without jQuery would be appreciated.
我对所有这些都是新手,所以不带jQuery的简单答案可能会受到赞赏。
In the PHP file: 在PHP文件中:
function checkDuplicateTesterName($tester_name)
{
$table_info = "TBL_TESTER_LIST";
$query_string = "select tester_name from $table_info where tester_name = $tester_name";
$result = @mysql_query($query_string) or die (mysql_error());
$checkTester = mysql_num_rows($result);
if($checkTester>0)
{
echo $message = "Error, please check again."; //I want to pass this
}
}
In the external js file: 在外部js文件中:
function checkTester()
{
var tester_name = document.getElementById("tester_name").value;
var page = "database.php";
var parameters = "&tester_name="+tester_name+"&action=check";
var xmlhttp = new XMLHttpRequest();
if(xmlhttp==null)
{
alert("Your browser does not support ajax!");
return false;
}
xmlhttp.onreadystatechange=function()
{
if(xmlhttp.readyState==4)
{
alert("function success."+message); //Alert error message from PHP here
}
};
xmlhttp.open("GET", page+"?"+parameters, true);
xmlhttp.send(null);
}
The response is in the responseText
field of the XHR object, so you need to do: 响应位于XHR对象的
responseText
字段中,因此您需要执行以下操作:
xmlhttp.onreadystatechange=function()
{
if(xmlhttp.readyState==4)
{
var message = xmlhttp.responseText;
alert("function success."+message); //Alert error message from PHP here
}
};
You don't need to use JSON if you're just returning a string. 如果您只是返回一个字符串,则无需使用JSON。 JSON is useful if you're returning an array or object.
如果您要返回数组或对象,则JSON非常有用。
You can do it by defining global variable which value comes from php like this one below. 您可以通过定义全局变量来实现,该变量的值来自php,如下所示。
<script type="text/javascript">
var message = '<?= $message ?>';
</script>
That is the simple way. 那是简单的方法。
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