使用Ajax提交文件上传的Wordpress表单

Question

I am trying to create form and submitting this with ajax. So the page wont reload. I don't have a lot of experience with ajax and I am trying to find as much information as I can.

Right now in my code I can sbmit form without reloading. But I have a field for uploading files. I know It is a bit different to do this and I also found some examples but so far no luck. For example Ajax file upload in Wordpress - can't pass FormData

Right now I have My Ajax code like this:

Ajax

(function($) {

jQuery(document).ready(function() {

    // when user submits the form
    jQuery(document).on('submit', '.form-assignment', function(event) {

        var error_elm = jQuery('.ajax-error');
        var response_elm = jQuery('.ajax-response')
       // var widgetId = grecaptcha.reset(container);
        error_elm.html('');
        response_elm.html('');

        // prevent form submission
        event.preventDefault();

        var form_elm = jQuery(this);

        var url = form_elm.data('url');
        var action = form_elm.data('action');
        var form_data = new FormData();

        var data = {
            action: action,
            form_data : form_data
        };

        // add loading message
        response_elm.html('Loading...');

        jQuery.ajax({
            type : 'POST',
            url : url,
            data : data,
            processData: false,
            contentType: false,
            enctype: 'multipart/form-data',
            dataType : 'json',
            async : true
        }).success(function(response) {

            error_elm.html('');
            response_elm.html('');

            if(response.status !== 'success') {
                // something went wrong
                if(response.message) {
                    error_elm.html(response.message);
                    return;
                }

                // don't know ?
            }

            // success!!

            // log data
            console.log(response);

            // display data
            response_elm.html(response.message);
            $("#form-assignment").trigger("reset");
            grecaptcha.reset();
        }).error(function(response) {
            error_elm.html('');
            response_elm.html('');

            error_elm.html(response.statusText);
        });
    });

});



})( jQuery );

My form:

 <div class="ajax-error" style="color: red;"></div>
    <form class="form-assignment" name="form_assignment" id="form-assignment"
          method="post" enctype="multipart/form-data"
          data-url="<?php echo esc_url( admin_url( 'admin-ajax.php' ) ) ?>" data-action="form_submit1">
          <label>name:</label>
          <input type="text" name="customer-field-text"pattern="[a-zA-Z0-9 ]+" placeholder="<?php echo $field->label ?>" size="40"/>
          <label>file upload</label>
           <input type="file"  name="customer-field-upload" id="customer-field-upload"
                           multiple="false"/>
    </form>

Right now this is how far I got. This is not my full form I have already added nonce and other required settings for sequrity. When I check input file It keep displaying error message that the field is empty.

My form handler

function handle_form_submission (){
global $wpdb;
$response = array(
    'status' => 'error',
    'message' => '',
);


parse_str($_POST['form_data'], $form_data);

//global $error;
$error = new WP_Error();

    if (empty($_POST['customer-field-name'])  ) {
    $error->add('empty','Name is required.');
}

    if (empty($_POST['customer-field-upload']) && empty($_FILES["customer-field-upload"]["name"])) {
    $error->add('empty','select an file.');
}

if ( !empty( $error->get_error_codes() ) ) {
    $error_messages = $error->get_error_messages();

    $error = '';
    foreach($error_messages as $error_message) {
        $error .= '<p>'.$error_message.'</p>';
    }

    $response['message'] = $error;

    wp_send_json( $response );
    wp_die();
}
$name                 = sanitize_text_field( $form_data["customer-field-name"] );
$upload                 = sanitize_text_field( $form_data["customer-field-upload"] );


require_once( ABSPATH . 'wp-admin/includes/image.php' );
require_once( ABSPATH . 'wp-admin/includes/file.php' );
require_once( ABSPATH . 'wp-admin/includes/media.php' );

 media_handle_upload( 'customer_field_upload', $form_data['post_id'] );

}

    add_action( 'wp_ajax_form_submit1', 'handle_form_submission' );

    // ajax hook for non-logged-in users: wp_ajax_nopriv_{action}
    add_action( 'wp_ajax_nopriv_form_submit1', 'handle_form_submission' );

So My question is What can I do or add in my ajax or form handler to get file upload submit with Ajax working. Any suggestion, advice or some existing example that are familiar will be appreciated. I am practicing with WordPress and Ajax that is how far I got.

I have tried to use FormData but still no luck so far.

Answer 1

Here is some tips to make work your provided form:

Form:

<div class="ajax-error" style="color: red;"></div>
<form class="form-assignment" name="form_assignment" id="form-assignment" method="post" enctype="multipart/form-data"
      data-url="<?php echo esc_url(admin_url('admin-ajax.php')) ?>" data-action="form_submit1">
    <label>name:</label>
    <input type="text" name="customer-field-text" pattern="[a-zA-Z0-9 ]+" size="40"/>
    <label>file upload</label>
    <input type="file" name="customer-field-upload" id="customer-field-upload" multiple="false"/>
    <input type="submit" value="Submit" name="submit">
</form>

I removed placeholder="<?php echo $field->label ?>" from your text input, because it's coming from custom code, which you didn't provide.

Ajax.js:

jQuery(document).ready(function ($) {
    // when user submits the form
    jQuery(document).on('submit', '.form-assignment', function (event) {

        var error_elm = jQuery('.ajax-error');
        var response_elm = jQuery('.ajax-response');
        error_elm.html('');
        response_elm.html('');

        event.preventDefault();

        var form_elm = jQuery(this);

        var url = form_elm.data('url');
        var action = form_elm.data('action');
        var file = form_elm[0][1].files[0];
        var customer_field_text = form_elm[0][0].value;
        var form_data = new FormData();
        form_data.append('action', action);
        form_data.append('customer-field-upload', file);
        form_data.append('customer-field-name', customer_field_text);

        response_elm.html('Loading...');

        jQuery.ajax({
            type: 'POST',
            url: url,
            data: form_data,
            processData: false,
            contentType: false,
            cache: false
        }).success(function (response) {

            error_elm.html('');
            response_elm.html('');

            if (response.status !== 'success') {
                // something went wrong
                if (response.message) {
                    error_elm.html(response.message);
                    return;
                }

                // don't know ?
            }

            response_elm.html(response.message);
            $("#form-assignment").trigger("reset");

        }).error(function (response) {
            error_elm.html('');
            response_elm.html('');

            error_elm.html(response.statusText);
        });
    });

});

NOTE: You're using var form_elm = jQuery(this);, which returns object of jquery with all Form content. That's why I used it for accessing input information. Instead you can access to form inputs with their name, class, id, placeholder and etc.

What changed:

1. removed (function($) {} wrapper and instead used jQuery(document).ready(function ($) {});. This is just for note. There is no need to wrapp your jquery to have access to $.

2. We're getting file and name from inputs with lines below:

   var file = form_elm[0][1].files[0];
   var customer_field_text = form_elm[0][0].value;
   

3. We're adding action for WordPress and form inputs with their values into FormData:

   form_data.append('action', action);
   form_data.append('customer-field-upload', file);
   form_data.append('customer-field-name', customer_field_text);
   

   Here you can change the name of array we're sending. For ex., we will recieve file in the array with key customer-field-upload and can use it such way:

   $_FILES['customer-field-upload']
   

4. async : true: this line we don't need. It's true by default. enctype: 'multipart/form-data', we don't need, too.
5. data: form_data,: we are sending everything only using one form_data variable( FormData object ).

PHP file:

1. I didn't use add_action('wp_ajax_nopriv_form_submit1', 'handle_form_submission'); because there is nothing related to nonce in your provided code

2. Your $_POST will contain:

   Array
   (
      [action] => form_submit1 //action, which we used to send and accept Ajax request
      [customer-field-name] => some input value in the name field
   )
   

   You can access to name input using $_POST['customer-field-name'].

3. Your $_FILES will contain:

   Array
   (
       [customer-field-upload] => Array
           (
               [name] => input file name
               [type] => input file type
               [tmp_name] => temp file
               [error] => 0 
               [size] => some size
           )
   
   )
   

   You can work with input file using $_FILES['customer-field-upload']

---

EDIT: Appended functional to add all inputs with several lines of code:

Form:

<div class="ajax-error" style="color: red;"></div>
<form class="form-assignment" name="form_assignment" id="form-assignment" method="post" enctype="multipart/form-data"
      data-url="<?php echo esc_url(admin_url('admin-ajax.php')) ?>" data-action="form_submit1">
    <label for="customer-field-text">name:</label>
    <input type="text" name="customer-field-text" id="customer-field-text" pattern="[a-zA-Z0-9 ]+" size="40"/>
    <label>file upload</label>
    <input type="file" name="customer-field-upload" id="customer-field-upload" multiple="false"/>
    <label for="select">select:</label>
    <select name="carlist" id="select">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
    </select>
    <label for="email">email: </label>
    <input type="text" name="email" id="email">
    <input type="submit" value="Submit" name="submit">
</form>

Ajax.js:

jQuery(document).ready(function ($) {
    // when user submits the form
    jQuery(document).on('submit', '.form-assignment', function (event) {

        var error_elm = jQuery('.ajax-error');
        var response_elm = jQuery('.ajax-response');
        error_elm.html('');
        response_elm.html('');

        event.preventDefault();

        var form_elm = jQuery(this);

        var url = form_elm.data('url');
        var action = form_elm.data('action');
        var file_input_name = jQuery('#form-assignment').find('input[type=file]').attr('id');
        var form_data = new FormData();

        form_data.append('action', action);

        jQuery.each(jQuery(':input:not([type=submit]):not([type=file])', '#form-assignment' ), function(i, fileds){
            form_data.append(jQuery(fileds).attr('name'), jQuery(fileds).val());
        });
        jQuery.each(jQuery(':input:not([type=submit]):not([type=text]):not([type=select])', '#form-assignment' )[0].files, function(i, file){
            form_data.append(file_input_name, file);
        });

        response_elm.html('Loading...');

        jQuery.ajax({
            type: 'POST',
            url: url,
            data: form_data,
            processData: false,
            contentType: false,
            cache: false
        }).success(function (response) {

            error_elm.html('');
            response_elm.html('');

            if (response.status !== 'success') {
                // something went wrong
                if (response.message) {
                    error_elm.html(response.message);
                    return;
                }

                // don't know ?
            }

            response_elm.html(response.message);
            $("#form-assignment").trigger("reset");

        }).error(function (response) {
            error_elm.html('');
            response_elm.html('');

            error_elm.html(response.statusText);
        });
    });

});

Here we used Jquery iterator to add several values from the loop into the FormData object. This is example and can be applied for checkboxes, textareas and etc.