How to Stop an Ajax request in prototype.js

Question is what will you do if you are using prototype.js(which is not having any abort method) for making a Ajax request and due to some circumstance you want to abort the ajax request raised. Well one can think that this is a narrow requirement, why will anybody need to do this because in the meantime request will be done and one might be having the response in return from server.

I hit this corner case where page content was loading from an Ajax request and which after rendering was firing another Ajax request to update the paginate-r(which is also self firing the request on response completion), but to my surprise i was not able to control the "Ajax request to update paginate-r" and hence i am creating the self firing request but am not able to destroy them.

And i don;t know for what reason there is no "ajaxRequest.abort()" method. And i found the answer from a narrow corner of http://blog.pothoven.net/2007/12/aborting-ajax-requests-for-prototypejs.html and it worked and just to increase the find-ability of this solution am re-writing the post.

introduce a method abort like this for prototype.js

Ajax.Request.prototype.abort = function(){
this.transport.onreadystatechange = Prototype.emptyFunction(); //prevent state change callbacks from being issues
this.transport.abort(); //abort the XHR
Ajax.activeRequestCount--; //updates the request counter
};

and then in your code
write it somewhere so that it is executed only once

<script>
var cw_paginator_request = null;
</script>

and then to assign the request if null else abort the request and fire a new request, like this

<script>
if(cw_paginator_request != null){
cw_paginator_request.abort();
}
cw_paginator_request = <%=remote_function(:url => {:controller => "some_controller", :action => "update_paginator", :id => @selected_id }) -%>;
</script>

Hopefully it might help somebody in need :)

send_file or send_data in link_to_remote

Hi guys,

really really long time i did anything here :).. and no this time not an usual bhaana(excuse) will do but an genuine reason.. was busy building something good.. and it is a secret(just can't disclose it here like this).

Anyhow coming to point.. i was doing a general routine development task for my company and i got hit by a situation like this.. where i was making an ajax call to a controller/action and in response i was sending a stream i.e (send_data and send_file) but as the post was xmlhttp everything was working fine but download was not available (and yeh over here i coded it for download not the inline stuff). What to do now.... i searched it ya ya googled it and response was not a solution that i can rely on(it might not be google's fault must be mine, but why am i favoring it.. it must be google fault lol :)) )

So i solved it my own way by redirecting the update to other action and coding the stream in the newly redirected action :)

Here are some snippets of it....

<%=link_to_remote "Export the result",:url => {:controller => "some_controller", :action => "ask_to_export"},:with => "'record_ids=1-2-3-4-5-6'" -%>

def ask_to_export
render :update do |page|
page.redirect_to :action => "process_and_export", :record_ids => params[:record_ids]
end
end

def process_and_export
outfile = ""
CSV::Writer.generate(outfile) do |csv|
csv << ["praveen","kumar","sinha",1,2,3,nil,""]
end
send_data outfile, :type => 'text/csv; charset=iso-8859-1; header=present', :disposition => "attachment; filename=report_#{Time.now.to_f.to_s}.csv"
end

I hope this must be helpful to some one stucked over here and googling it

Thanks :)

form inside form. is it possible?

Hi guys,

whatever i can recall i think i got hit by this problem earlier too, but at that time certainly i was not a blogger, in fact i was lazy of writing too :)) and see it came again, this issue is of placing a html form inside another.
It sounds messy right?? ya ya i know, but some how this was one of the requirement for one of the application that i was developing.

was having a html form with list item as radio box option but later it came to the requirement that label of radio button too should be update able so i tried putting up form_remote_tag(the rails method) for labels but it was not working in fact html form was not coming on to the page(as i was loading it through partials).

So went in for :with parameter in using the remote functions for prototype helper

the host rhtml

<% form_tag url_for(:controller => "controller_name", :action => "action_name") do %>
<%@some_collection_hash.each do |key,value| -%>
<span><%=key%></span>
<%value.each do |single_item|-%>
<div class="sbc" style="width:30px;">
<%=radio_button_tag("publisher[#{key}]", single_item.id,false,:disabled => (single_item.status != "valid")) -%>
</div>
<div class="sbc" id="<%=single_item.id-%>_batch">
<%=render :partial => "/xyz/partial_one", :locals => {:single_item => single_item, :key => key} -%>
</div>
<%end-%>
<%end-%>
<%= submit_tag "Get Summary"%>
<% end %>

The view partial

<ul>
<li class="head_li">Satus:</li>
<li class="dotless_li">
<%=select_tag("#{single_item_id}_status", options_for_select(["valid","invalid","pending","running","deleted","summarize"],@single_item.status)) %>
</li>
</ul>
<ul>
<li class="head_li">Description:</li>
<li class="dotless_li"><%=text_area_tag "#{single_item_id}_desc", @single_item.comments, :rows => 3, :cols => 30 -%></li>
</ul>
<input type="button" value="Close" onclick="<%= remote_function(:update => "options",
:url => {:controller=> :controller_name, :action => :show_single_iteminfo ,:single_item_id => single_item_id, :key => key},
:update => { :success => "#{single_item_id}_single_item", :failure => "#{single_item_id}_single_item" }) -%>" />

<input type="button" value="Save" onclick="<%= remote_function(:update => "options",
:url => {:controller=> :controller_name, :action => :save_single_iteminfo ,:single_item_id => single_item_id, :key => key},
:with => "'description='+$F('#{single_item_id}_desc')+'&'+'status='+$F('#{single_item_id}_status')",
:update => { :success => "#{single_item_id}_single_item", :failure => "#{single_item_id}_single_item" }) -%>" />