javascript - Call js function from code-behind (Not as startupScript) -

basically want is:

1. click on button delete record.
2. delete record if specific column (location) null (this done , works fine)
3. delete record, if specific column not null, ask user confirm.

so step 3 tricky part. ajax, call deletechannel(url) see below, calls proper method in code-behind. here tricky part:

   if (channel != null && channel.location != null)     {          // how do this? (notice code-behind)          showdialogthatasksusertoconfirm()     } 

the code: showdialogthatasksusertoconfirm() needs call client saying "the location column not null", , wait user delete anyway, or cancel.

i have code call method in code behind:

function deletechannel(url) {  $.ajax({     url: url,     type: "post",     cache: false,     contenttype: 'application/html; charset=utf-8',     data: $("form").serialize(),     datatype: 'html',     success: function (msg) {         showdialog('successdiv');     },     error: function (msg) {         alert("error");         showdialog('errordiv');     } }); } 

and showdialog(...) looks this:

function showdialog(divid) { $("#" + divid).dialog({     show: "clip",     hide: "clip",     buttons: {         ok: function () {             $(this).dialog("close");         }     } }); } 

the code-behind looks this:

[httppost]     public actionresult deletechannel(int id)     {         var statuscode = new httpstatuscode();          using (var context = new maanegriscontext())         {             var channel = context.channels.firstordefault(x => x.id == id);              if (channel != null && channel.location != null)             {                 if (confirmation()) //the confirmation() method not implemented yet, should ask user confirm                 {                     context.channels.remove(channel);                     context.savechanges();                      list<channelmodel> updatedchannellist = new list<channelmodel>();                     context.channels.addrange(context.channels);                        return view("channeldetails", updatedchannellist);                 }             }   } 

here view:

<table style="border: ridge 1px">     <tr>         <th>name</th>         ...     </tr>     @{         foreach (var item in model)         {             <tr>                 <td>@html.displayfor(m => item.channelname)</td>                 <td>@html.displayfor(m => item.description)</td>                 <td>@html.displayfor(m => item.unit)</td>                 <td>@html.displayfor(m => item.location.stablename)</td>                 <td>@html.displayfor(m => item.creationdate)</td>                 <td>@html.displayfor(m => item.lastedited)</td>                 <td>@html.displayfor(m => item.extranote)</td>                 <td><a href="@url.action("copychannel", "channel", new { id = item.id })"><span class="glyphicon glyphicon-copy"></span></a></td>                 <td><a href="@url.action("editchannel", "channel", new { id = item.id })"><span class="glyphicon glyphicon-edit"></span></a></td>                 <td><a href="#" onclick="deletechannel('@url.action("deletechannel", "channel", new { id = item.id })')">                        <span class="glyphicon glyphicon-remove"></span></a>                                         </td>             </tr>         }     }         </table> <br/><br/> <div style="display: none;">    @* @{ html.renderpartial("_createchannel"); } *@ </div> <h5>@html.actionlink("opret en ny kanal", "registerchannel", "channel")</h5>  <div id="cautiondiv" title="bekræft sletning" style="display: none;">     <p style="color: red;">the channel has location. sure want delete?</p> </div>  <div id="successdiv" title="info" style="display: none;">     <p style="color: green;">deleted</p> </div> 

this approach, , not final, if there better solutions, please let me know

you can't call js codebehind, ajax method can return indication asking user:

if (channel != null && channel.location != null) {    return 'cannot-delete'; } 

and ajax method see on it's success function, , prompt user:

$.ajax({     url: url,     type: "post",     cache: false,     contenttype: 'application/html; charset=utf-8',     data: $("form").serialize(),     datatype: 'html',     success: function (msg) {         if (msg == 'cannot-delete') {              showdialogthatasksusertoconfirm();         } else showdialog('successdiv');     },     error: function (msg) {         alert("error");         showdialog('errordiv');     } }); 

the method showdialogthatasksusertoconfirm should ask users's confirmation in javascript, , if allowed, submit forced delete of record.