how to generate barcode in c# net with example The save_event RJS Template in app/views/ajax/save_event.rjs in Font

Paint QR Code JIS X 0510 in Font The save_event RJS Template in app/views/ajax/save_event.rjs

Listing 7-20. The save_event RJS Template in app/views/ajax/save_event.rjs
Print QR-Code In None
Using Barcode generation for Font Control to generate, create QR image in Font applications.
www.OnBarcode.com
GTIN - 13 Drawer In None
Using Barcode generation for Font Control to generate, create EAN 13 image in Font applications.
www.OnBarcode.com
# Replace the count div page.replace_html 'count', :partial => 'events_count' page.visual_effect :highlight, 'count' # Clean up the UI page['event_title'].value = '' page['event_location'].value = '' page['event_title'].focus
GS1 - 12 Creation In None
Using Barcode drawer for Font Control to generate, create UPC Code image in Font applications.
www.OnBarcode.com
Creating ECC200 In None
Using Barcode encoder for Font Control to generate, create Data Matrix ECC200 image in Font applications.
www.OnBarcode.com
CHAPTER 7 IMPROVING INTERACTION WITH AJAX
USS Code 39 Printer In None
Using Barcode maker for Font Control to generate, create USS Code 39 image in Font applications.
www.OnBarcode.com
Code 128 Code Set C Creation In None
Using Barcode maker for Font Control to generate, create Code-128 image in Font applications.
www.OnBarcode.com
# Hide the indicator image page['indicator_form'].hide
Draw PDF417 In None
Using Barcode drawer for Font Control to generate, create PDF417 image in Font applications.
www.OnBarcode.com
USS Codabar Creator In None
Using Barcode generation for Font Control to generate, create Code 2 of 7 image in Font applications.
www.OnBarcode.com
The first line tells the RJS engine to generate JavaScript code to replace the HTML element count with the contents of event_count partial. The second line creates the code to highlight the recently changed element. Notice that we re writing all this in pure Ruby. The page variable gives us access to the rendered page, and we can call methods on it. You can also use the page object to access elements by index. That s how we re manipulating the field values and the indicator image.
Quick Response Code Creator In None
Using Barcode generator for Online Control to generate, create Denso QR Bar Code image in Online applications.
www.OnBarcode.com
Denso QR Bar Code Generator In Visual Studio .NET
Using Barcode creation for ASP.NET Control to generate, create Denso QR Bar Code image in ASP.NET applications.
www.OnBarcode.com
page[element_id] # => accesses the specified element
Generate ANSI/AIM Code 39 In VS .NET
Using Barcode creator for .NET Control to generate, create Code 3 of 9 image in VS .NET applications.
www.OnBarcode.com
PDF-417 2d Barcode Decoder In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
We reset the value of the event_title element using page['event_title'].value = ''. Similarly, we focus it using page['event_title'].focus. The page object also has several methods you can use to interact with your web pages, as listed in Table 7-4.
DataMatrix Creator In Visual C#
Using Barcode drawer for Visual Studio .NET Control to generate, create Data Matrix image in VS .NET applications.
www.OnBarcode.com
Code 128 Code Set A Reader In VB.NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Table 7-4. Methods Available to the Page Object in RJS Templates Method
Scanning Data Matrix 2d Barcode In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
ECC200 Reader In C#.NET
Using Barcode reader for .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
replace replace_html
Code 128 Code Set A Generation In VS .NET
Using Barcode drawer for Reporting Service Control to generate, create Code 128A image in Reporting Service applications.
www.OnBarcode.com
UPC Code Reader In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Description
Painting GTIN - 128 In Visual C#.NET
Using Barcode generation for VS .NET Control to generate, create EAN / UCC - 13 image in Visual Studio .NET applications.
www.OnBarcode.com
Generating Barcode In Java
Using Barcode maker for Android Control to generate, create Barcode image in Android applications.
www.OnBarcode.com
Replaces the entire element with content supplied Replaces the inner HTML of the given element with the content supplied Inserts HTML at the specified position relative to the given element Hides the given element or elements if they are visible Shows the given element or elements if they are hidden Returns an array of elements that match the given CSS selector Replaces the contents of the element with the output of a partial with the same name
Example
page.replace :content, '<div id="content">Howdy!</div>' page.replace_html :content, :partial => 'content' page.insert_html :top, 'Total', content_tag(:h3, "$150.00") page.show 'savings' page.show 'savings', 'account' page.selector '#items li' page.reload 'content'
insert_html
hide show select reload
Our RJS template is in place, but we still need to update the call to form_remote_tag now that we ve offloaded most of its work. The modified code is shown in bold in Listing 7-21.
CHAPTER 7 IMPROVING INTERACTION WITH AJAX
Listing 7-21. The Updated events Template in app/views/ajax/events.rhtml
Add a new event: <% form_remote_tag(:loading => $('indicator_form').show(), :url => { :controller => 'ajax', :action => "save_event" }) do %> <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>
Notice that we ve removed all but the :loading callback. This is important if you re switching from in-line updates to RJS, remember to remove the :update parameter from your helper calls. If you don t, the in-line :update will clobber the one performed by the RJS.
Implementing RJS in the Controller
In some situations, your RJS file can be just a few lines of code, or it could even be a single call, and it might seem like overkill to create and manage a new template with such a small amount of code. In those cases, you can implement RJS responses directly from the controller action using render :update. If we were so inclined, we could do away with the save_event.rjs template and implement the entire response in the save_event action. Here s how it would look:
def save_event current_user.events.create(params[:event]) count_events render :update do |page| # Replace the count div page.replace_html 'count', :partial => 'events_count' page.visual_effect :highlight, 'count' # Clean up the UI
CHAPTER 7 IMPROVING INTERACTION WITH AJAX
page['event_title'].value = '' page['event_location'].value = '' page['event_title'].focus # Hide the indicator image page['indicator_form'].hide end end
Deciding whether to put RJS code in its own file or on the controller might come down to personal preference, so try both approaches and stick with the one you like best. For RJS responses that are long, we recommend that you create an RJS template, to help keep your controller clean of view code and easy to read. For RJS responses that are one or two lines long, keeping the code in the controller may save you some time when coding. For more information about RJS templates, including usage examples, be sure to check out the Rails API documentation at http://api.rubyonrails.org/classes/ ActionView/Helpers/PrototypeHelper/JavaScriptGenerator/GeneratorMethods.html.
Summary
To be sure, Ajax is a large topic. Entire books and conferences are devoted to this subset of technology alone, so it goes without saying that we ve only scratched the surface here. Still, in short order, you ve learned the basics about implementing Ajax in your Rails applications, and you know where to go when you need to dig deeper. We started by introducing the Prototype library and highlighting a few of its finer points. These include its various shortcuts for accessing elements and input fields, among other features. We also showed you how to include all the necessary JavaScript libraries, including your own application-specific JavaScript functions (application.js) using javascript_include_tag :defaults. You learned how to make remote Ajax calls using link_to_remote, and how to post forms remotely using form_remote_tag. We also covered polling the page for changes using observe_field and observe_form. We introduced the script.aculo.us library and showed you how it integrates with Rails to make implementing seemingly complex features, like auto-complete and in-place editing, a snap. Finally, you learned about RJS templates and how they enable you to harness the power of Ruby to do your JavaScript bidding, be it from templates or from the controller. At this stage, you have a solid grasp of the Action Pack side of web development with Rails. Next, we ll look at how you can conquer another common component of web application development: sending mail.
Copyright © OnBarcode.com . All rights reserved.