how to generate barcode in c# net with example Adding an Event Form to app/views/ajax/events.rhtml in Font

Encoding Quick Response Code in Font Adding an Event Form to app/views/ajax/events.rhtml

Listing 7-7. Adding an Event Form to app/views/ajax/events.rhtml
Creating QR In None
Using Barcode creation for Font Control to generate, create QR Code ISO/IEC18004 image in Font applications.
www.OnBarcode.com
Creating Data Matrix ECC200 In None
Using Barcode creation for Font Control to generate, create ECC200 image in Font applications.
www.OnBarcode.com
Add a new event: <% form_remote_tag(:update :loading :complete :url
Barcode Generator In None
Using Barcode generator for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Code 3/9 Drawer In None
Using Barcode generation for Font Control to generate, create Code 39 Full ASCII image in Font applications.
www.OnBarcode.com
=> => => =>
Drawing Code 128 In None
Using Barcode encoder for Font Control to generate, create Code 128B image in Font applications.
www.OnBarcode.com
Create PDF 417 In None
Using Barcode printer for Font Control to generate, create PDF417 image in Font applications.
www.OnBarcode.com
"count", $('indicator_form').show(), $('indicator_form').hide(), { :controller => 'ajax', :action => "save_event" }) do %>
UPC-A Supplement 2 Printer In None
Using Barcode creator for Font Control to generate, create GTIN - 12 image in Font applications.
www.OnBarcode.com
Creating UPCE In None
Using Barcode maker for Font Control to generate, create UPC-E Supplement 5 image in Font applications.
www.OnBarcode.com
<p>Title<br/><%= text_field 'event', 'title' %></p> <p>Location<br/><%= text_field 'event', 'location' %></p> <%= submit_tag 'Save' %> <%= image_tag 'indicator.gif', :id => 'indicator_form', :style => 'display:none' %> <% end %> <div id="count"> <%= render :partial => "events_count" %> </div>
QR Code 2d Barcode Creation In Objective-C
Using Barcode drawer for iPad Control to generate, create QR-Code image in iPad applications.
www.OnBarcode.com
Make QR Code In Objective-C
Using Barcode generator for iPhone Control to generate, create QR Code ISO/IEC18004 image in iPhone applications.
www.OnBarcode.com
CHAPTER 7 IMPROVING INTERACTION WITH AJAX
Create Linear 1D Barcode In Visual Basic .NET
Using Barcode generator for .NET framework Control to generate, create 1D Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
DataMatrix Creator In None
Using Barcode generator for Excel Control to generate, create Data Matrix 2d barcode image in Microsoft Excel applications.
www.OnBarcode.com
The code for the view contains a form with Title and Location fields, and an HTML div element that contains the number of existing events in the database. As soon as the new event is saved, the div content will be updated with the new number of items in the database. Notice that we re putting the view code that displays the number of events in its own partial to make it easier to update that value in the browser with the same content. Let s make that partial now, adding the code shown in Listing 7-8 to app/views/ajax/ _events_count.rhtml. Listing 7-8. The app/views/ajax/_events_count.rhtml Partial
ANSI/AIM Code 39 Maker In Java
Using Barcode creator for Android Control to generate, create Code-39 image in Android applications.
www.OnBarcode.com
Generating Code 128A In Visual C#
Using Barcode maker for VS .NET Control to generate, create Code 128 image in .NET framework applications.
www.OnBarcode.com
<p>We have <%= @event_count %> great events in our application!</p>
Making UPC Code In Objective-C
Using Barcode printer for iPad Control to generate, create UPC-A Supplement 5 image in iPad applications.
www.OnBarcode.com
Barcode Generation In Visual Studio .NET
Using Barcode generator for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
Next, we need to add a couple methods to the controller to make this come together. The new code is shown in Listing 7-9. Listing 7-9. Adding count_events and save_event Methods to app/controllers/ ajax_controller.rb
Data Matrix ECC200 Decoder In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Generate GS1 DataBar-14 In .NET
Using Barcode generator for VS .NET Control to generate, create GS1 DataBar Limited image in VS .NET applications.
www.OnBarcode.com
class AjaxController < ApplicationController #... def events count_events end def save_event Event.create(params[:event]) count_events render :partial => "events_count" end private def count_events @event_count = Event.count end end
Code39 Generation In C#
Using Barcode maker for VS .NET Control to generate, create Code 39 image in .NET applications.
www.OnBarcode.com
UCC - 12 Generator In None
Using Barcode generation for Office Excel Control to generate, create GTIN - 12 image in Microsoft Excel applications.
www.OnBarcode.com
The first action is called to load the page the first time; it only needs to display the form and the number of events currently in the database, which we do by creating and calling a private count_events method to expose the @event_count variable to the view. The save_event action is called when the user clicks the form s Save button. It receives all the parameters from the request, creates a new Event object, and saves it to the database. It then renders the events_count partial, which updates in the DOM object defined by the :update parameter in the form_remote_tag helper.
CHAPTER 7 IMPROVING INTERACTION WITH AJAX
You can see that Rails deals with both Ajax and regular form submission in the same way, so there s nothing new to learn. This saves us a lot of time, since we can trust that the params method will return all the parameters without any extra effort. Try this out now by running the application and browsing to http://localhost:3000/ ajax/events. You ll notice that this approach makes adding new events very easy and fast. To further enhance this example, we can clear the text box with the event title and location after the form is submitted, which will allow users to enter multiple events without having to remove their hands from the keyboard. This technique makes data entry a lot more efficient. To do this, we need to create a new JavaScript function that, in addition to hiding the progress indicator, also changes the text box value to an empty string. Enter the JavaScript code shown in Listing 7-10 into the app/view/ajax/events.rhtml file.
Listing 7-10. Adding JavaScript to app/view/ajax/events.rhtml
<script language="Javascript"> function eventAdded() { $('indicator_form').hide(); $('event_title').value = ''; $('event_location').value = ''; $('event_title').focus; } </script>
Now we just need to change the form_remote_tag call to use this function in the complete callback call. Change the parameter in the form_remote_tag call in the app/view/ajax/events.rhtml file to eventAdded(), as shown in Listing 7-11.
Listing 7-11. Changing the form_remote_tag Call in app/view/ajax/events.rhtml
<% form_remote_tag :update :loading :complete :url => => => => "count", $('indicator_form').show(), "eventAdded()", { :controller => 'ajax', :action => "save_event" } do %>
Figure 7-6 shows how this new form works.
CHAPTER 7 IMPROVING INTERACTION WITH AJAX
Figure 7-6. Creating new events
CHAPTER 7 IMPROVING INTERACTION WITH AJAX
Tip
link_to_remote, form_remote_tag, observe_form, and observe_field all accept the same options, including the callback methods.
Polling for Changes with observe_field and observe_form
If you have ever used Gmail (http://gmail.com), we re sure that you love the fact that it saves a draft of the email you type as soon as you stop typing for a couple of seconds. This happens automatically in the background, without interrupting your interaction with the application. We can do the same in our events application: every time the user starts typing an event, we can save the incomplete record to a persistent storage system such as the database, cookie, or session variable. If the user s computer crashes or the browser is accidentally closed, we ll be able to retrieve the incomplete item, and bring a great smile to the user s face. We can accomplish this with the observe_field and observe_form helpers. The observe_field and observe_form helpers work in a similar way to each other, but they act on different elements: The observe_field helper acts on a specific form field, which could be the event title or location. The observe_form helper acts on all the fields of the specified form. The output of the observe_field and observe_form helpers is a call that instantiates a Form.Observer object or a Form.Element.Observer object, respectively. These are objects provided by Prototype that check the contents of the elements you want to observe. To demonstrate, we ll use observe_form with the new event form we created in the previous section. As the user fills in the form, the page will send information to the server that will be saved to the session. This will bring the added benefit that if users accidentally navigate to a different page, the event they were entering will be kept during the session and will be shown when they return to the event form. The code to display the form and create the Observer object goes in the view. Modify the existing app/views/events/new.rhtml file to look like Listing 7-12.
Copyright © OnBarcode.com . All rights reserved.