dongyan2267 2019-02-18 15:16
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单击“提交”按钮后如何保持选定的下拉值

I want to show selected data after click on submit.I have search too much but not get proper answer.

enter image description here

i used this code but what will be the next step i am not getting this.

if($actiondone!=''){
    echo "<script>
        $('#actiondoc').val();
        </script>";
}

Please guide me for solutuion

Thanks

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  • dqbr37828 2019-02-18 17:42
    关注

    You cannot use PHP to interact with the user.

    After the page has rendered, PHP is finished. If you want to interact with the user (i.e. detect changes to drop-downs, etc) you must use jQuery/javascript only.

    For your example, you need to have the jQuery code pre-existing in the page - that is, the javascript gets written into the DOM as the page is being initially rendered. You can add the jQuery/javascript code as part of the HTML, or you can echo that code in PHP as the page is being built -- but it must be on the page when the user gets control of the DOM.

    Working demo:

    $(function(){
        $('#form_submit').click(function(){
            alert( $('#actiondoc').val() );
            return false; //this line cancels the SUBMIT action of the form
        });
        
        $('#actiondoc').change(function(){
          alert('You chose: ' + $(this).find('option:selected').text() );
        });
    });
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
    <form id="your_form">
        <select id="actiondoc">
            <option value="">Choose:</option>
            <option value="chg">change of tyre</option>
            <option value="rnw">renew tyre</option>
        </select>
        <input id="form_submit" type="submit" value="submit" />
    </form>


    You say that you want to show the selected choice after user clicks on submit, but there might be a problem with that idea:

    When user clicks submit, an HTML form will immediately (a) get the values of the form controls and (b) deliver them to the page specified on the <form action="new_page.php" method="post"> -- so, in this code right here, the browser will navigate over to new_page.php and deliver the form values to that page.

    The point is: the page will change (unless you are using AJAX - are you?) - so you cannot show anything more on that page because the user isn't on that page any longer.

    So, you can show the value of the #actiondoc control on the new page, OR you can intercept the submit function, as I did in my demo above when I displayed the alert()

    If you tell us more about exactly what you want to do, we can help more.


    References:

    https://www.w3schools.com/xml/ajax_intro.asp

    AJAX vs Form Submission

    YouTube - Simple AJAX Contact Form - HTML, PHP, AJAX

    </div>
    
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