我如何在php中获取表单字段的值（字段是通过javascript创建的）？

Question

I have created the field using the java script (inner Html) and when I use $_POST['field name'] it shows undefined index .

Here is the code for the field:

function showfield(name){
    if(name=='Masters'){
        document.getElementById('div1').innerHtml = '<label>College/University</label><input class="form-control " type="text" id="course" name="uni" placeholder="College/University" /> <br> <label>Course</label><input class="form-control " type="text" name="crse" placeholder="Course"/><br>';
    } 
}

I want to get the value of course and college to next page once the user clicks submit

Answer 1

You need to insert that input in HTML form element with corresponding submit button. So if you already have some form that contains submit button insert this new input to that form. If you don't have any form element just wrap the submit button to it and make sure you insert this new input in that form.

Here is small example (HTML form).

<form id="awesome-form" method="POST" action="path/to/php/script.php">
    <div id="place-for-input"></div>
    <button type="submit" name="awesome-form-submit">Submit</button>
</form>

And here is your JavaScript.

function showfield(name){
    if(name=='Masters'){
        document.getElementById('place-for-input').innerHtml = '<label>College/University</label><input class="form-control " type="text" id="course" name="uni" placeholder="College/University" /> <br> <label>Course</label><input class="form-control " type="text" name="crse" placeholder="Course"/><br>';
    } 
}

And in PHP you will access this information like this.

if (isset($_POST["awesome-form-submit"])) {
    $collegeOrUniversity = $_POST["uni"];
}

By the way, a better path of doing this would be to insert that new input directly to the form with insertAdjacentHTML.

document.getElementById('awesome-form').insertAdjacentHTML("afterbegin", '<label>College/University</label><input class="form-control " type="text" id="course" name="uni" placeholder="College/University" /> <br> <label>Course</label><input class="form-control " type="text" name="crse" placeholder="Course"/><br>');