jquery AJAX requests

Hallo, i am new to jquery, AJAX requests. Here is my html code in edit_page.php

                    <td>Action: </td>
                               <td class="notselected">
                                    <div id="action_response"></div>
                                    <select name="action_db1" id=<?php  echo $sel_page['Concession']; ?> onchange="updateaction(this);" >
                                        <option value=""></option>
                                        <option value="move">Move</option>
                                        <option value="copy">Copy</option>
                                        <option value="exclude">Exclude</option>
                                    </select>
                                </td>

and the javascript code is

function updateaction(item) {
        $.post("edit_page_advanced_actions.php", {concession:item.id, action:item.value, db_name:item.name},function(action_response) {
         $('#action_response').html(action_response);

        });
}

Here i am calling php script *edit_page_advanced_a开发者_Go百科ctions.php* in which i wrote some php code. I want to return messages from here based on the database updation to edit_page.php. i.e from the calling script.

EDIT:-

I am updating database in edit_page_advanced_actions.php. I want to return an error message or success message to edit_page.php. i.e from where this is triggered. For example "successfully updated", "Copied successfully","Failed to exclude" to the users based on db operations.

How this can be accomplished.

Thanks in advance!

You should return the error status in the http header using the php header function. For example:

header("Status: 400 Bad Request");
echo "The error is: ....";

You can then use$.ajax with a special error function:

$.ajax({
  type: 'POST',
  url: "edit_page_advanced_actions.php", 
  data: {
    concession:item.id, 
    action:item.value, 
    db_name:item.name
  },
  succes: function(data, action_response) {
     $('#action_response').html(action_response);
  },
  error: function(xhr, action_response) {
     // error code goes here
     alert(action_response);
  }
});

I suggest you return a json object in your server side method and use it as a response in your client side ajax call.

You could return a json object like

{ Success: true, ErrorMessage: 'An error happened' }

Because you're doing a $.post your action_response variable would be a json string, you will need to parse it into a javascript object.

Look at this for parsing the json response: http://api.jquery.com/jQuery.parseJSON/

and in your client side code:

if(!action_response.Success) {
  displayErrorMessage(action_response.ErrorMessage);
}

EDIT:

Look at this post to return a json object from PHP method

Returning JSON from PHP to JavaScript?