Welcome!

You will be redirected in 30 seconds or close now.

ColdFusion Authors: Yakov Fain, Jeremy Geelan, Maureen O'Gara, Nancy Y. Nee, Tad Anderson

Related Topics: Adobe Flex, ColdFusion, Machine Learning

Adobe Flex: Article

Your First Adobe Flex Application with a ColdFusion Backend

The wow factor plus usability
By Nahuel Foronda, Laura Arguello
Article Rating:
July 19, 2007 01:30 PM EDT
Reads:
 110,309

However, the compiler still complains that it can't find the TaskItem component. "But I just created it!" you say. The problem is that the main application doesn't know where to find it. Since you saved it in the same folder, you have to indicate that other components can be found there by adding the following attribute to the Application tag in the mytodolist.mxml file:

xmlns="*"

Lastly, declare the taskData variable in your new component (TaskItem.mxml) so that it will finally compile without errors:

<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" width="100%">
   <mx:Script>
     <![CDATA[
       [Bindable]
       public var taskData:Task = null;
     ]]>
   </mx:Script>
   <!-- place other code here -->
</mx:Canvas>

Why wouldn't it compile? Because when you put the tag <TaskItem> in the main application, you also specified the attribute: taskData="{taskList.currentItem}." This was necessary to be able to send the current task to the custom component during each loop of the Repeater. This variable has to be set as bindable so that you can bind to its properties in the controls inside this component.

If you look carefully, you'll see that this variable has the type "Task." This type refers to the ActionScript file automatically generated by the ColdFusion wizard. The properties of this class match exactly those of your Task ColdFusion component.

An instance of the TaskItem component (Figure 5) shows the description and priority of the task and a button to remove the task. As described above, the data is set when the component is instantiated by the Repeater and accessible in the variable "taskData" inside the component.

You can use the Design view to drag an Image, a Label, and a Button and put it in the Canvas. The Properties panel of the Design view shows common properties of the selected component. In that panel, set the text property of the Label as: {taskData.description} and the source property of the Image as: images/priority{taskData.priority}.png. Note that you should have a folder called "images" with an image for every priority you want to show. These images should be called "priorityNUMBER.png," where NUMBER should be replaced with the priority number (i.e.: 1, 2, 3).

Everything should compile, but unfortunately you won't be able to see anything because there's no data.

Getting Data from a ColdFusion Service
To load data from a service, you must use a RemoteObject. The simplest way to use a RemoteObject to call a ColdFusion service is by setting its destination to "ColdFusion" and its source to the path to that component. The application will call two methods on the TaskGateway component (generated by the wizard) so you can specify them explicitly inside the RemoteObject tag. When the response from the service comes back, you want a function to be called. The function to call will be different for each method, so you can specify it in the <mx:method> tag with the "result" attribute. Set the result of the method "getAll" to the function "tasksReceived(event)" and the result of the method "save" to the function taskSaved(event)."

<mx:RemoteObject
    id="myRemoteObject"
    destination="ColdFusion"
    source="mytodolist.taskGateway"
    fault="Alert.show(event.fault.faultstring, 'Error');">
    <mx:method name="getAll" result="tasksReceived(event)" />
    <mx:method name="save" result="taskSaved(event)" />
</mx:RemoteObject>

Inside a script block, implement the tasksReceived function as follows to set the source of the task ArrayCollection to what the service sent as a response of the getAll method:

private function tasksReceived(event:ResultEvent):void {
    tasks = new ArrayCollection();
    tasks.source = event.result as Array;
}

If you open TaskGateway.cfc, you'll see that the method "getAll" returns an array of Task objects. When you set that array to the source of the tasks ArrayCollection, the Repeater will get populated with this data since you declared it as the Repeater's dataProvider.

If Flex Builder didn't add the required import statements automatically, add:

import mx.controls.Alert;
import mx.rpc.events.*;
import mx.events.*;

The other function you need to implement is taskSaved. For now leave it empty; you'll complete it later.

private function taskSaved(event:ResultEvent):void {
}

Everything works, but...you still don't see anything on the screen. That's because you haven't called the service yet. Since you want to load the list of tasks as soon as the application loads, put a function call in the applicationComplete attribute of the Application tag. You'll set it to call a custom function called setUp():

applicationComplete="setUp()"

Then implement the function so that it sends the actual request to the server:

private function setUp():void{
    myRemoteObject.getAll.send();
}

Of course you still won't see anything if your database is empty. To test it out, just add a couple of records manually. You'll build the form to enter new items in the next section.

Published July 19, 2007 – Reads 110,309
Copyright © 2007 SYS-CON Media, Inc. — All Rights Reserved.
Syndicated stories and blog feeds, all rights reserved by the author.

More Stories By Nahuel Foronda

Nahuel Foronda is one of the founders of Blue Instant (http://www.blueinstant.com), a web development firm specializing in Rich Internet Applications where he has been creating award-winning applications and offering training for the last five years. He also maintains a blog, called AS Fusion (http://www.asfusion.com), where he writes about Flash, ColdFusion and other web technologies.

More Stories By Laura Arguello

Laura Arguello is one of the founders of Blue Instant (http://www.blueinstant.com), a web development firm specializing in Rich Internet Applications where she has been creating award-winning applications and offering training for the last five years. She also maintains a blog, called AS Fusion (http://www.asfusion.com), where she writes about Flash, ColdFusion and other web technologies.

Comments (17) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

Most Recent Comments
??? 10/30/07 01:47:34 AM EDT

Ipod MP4

????
????
????
????
??
????
????
????
???
????
???? 
donna 10/12/07 01:28:46 PM EDT

Unable to download the source code. When I got to page http://www.asfusion.com/projects/my-to-do-list/

I received a Coldfusion error:

A License exception has occurred.
You tried to access the Developer Edition from a disallowed IPThe Developer Edition can only be accessed from 127.0.0.1 and two additional IP addresses. The additional IP addresses are: 209.85.238.20,87.194.221.84

There are so many issues encountered with the tutorial apps out there, that dont work when people follow the isntructions exactly. We need apps that work when followed, and we need downloaded source code that will actually be there.
Lara 07/30/07 11:59:27 AM EDT

I am familiar with ColdFusion but completly new to Flex. I can't get the code to work and I am very frustrated. This isn't a good first application example if we can't work the code. Does anyone have the working source files? If so, please post a link to the corrected files. Thanks!
Jason 06/26/07 02:20:44 PM EDT

I love all the article put out by sys-con and found that they are top quality, that is until this one. I have been struggling with learning Flex and found this article and initally was excited because it looked like the article that was going to clear things up. Until I started in and realized that this article is full of mistakes. Flex is VERY case sensitive where as ColdFusion is not. Since this article is target at ColdFusion developers you need to make sure that the code is correct expecially in the area of case sensitivity because we ususally don't think in that manner (it is "faultString" not "faultstring"). Also you need to make sure that you are using the same name for functions. You have us call the addItem() function through a click event but then on the next page we create the saveItem() function to handle that click event. This won't work! Then we need to make changes to the generated CFCs. You show us the two lines of code that we need to add and simply state that they "should be added to the 'create' method." Ok, but where in the create method. I moved them all over and I continually get errors. I have yet to find a competent article for the Flex "newbie" that achieves its goal of showing how to do basic updates and adds with Flex and CF. I thought that this was going to be the one. Guess I was wrong!
KTK 06/07/07 03:53:09 PM EDT

I'm glad it's not just me! I've had to put this aside for a couple weeks to work on a CF project. Hopefully I can get back to it later this month. If you figure something out, let me know and if I figure it out, I'll let you know. In the meantime, maybe a savior will come along for both of us!
Scott 06/07/07 01:30:06 PM EDT

KTK - I have the same problem and I followed all of the instructions exactly.

Uf!
KTK 06/04/07 01:28:59 PM EDT

I'm getting an error that says "A file found in a source-path must have the same package structure '', as the definition's package, 'Task'. I've been beating my head against it for hours and can't figure out why I'm getting the error. Any ideas?
jex 11/04/06 11:26:10 AM EST

OK - I'm a bit new to both Flex and CF, but have been implementing the tutorial fine up until: "Going back to the main application file (mytodolist.mxml), switch to the design view and drag a new panel and inside drag your EditForm component." When I drag the EditForm component onto the panel, nothing happens. Would it be possible to explain exactly what has to be done here? Many thanks.
jex 11/04/06 11:24:25 AM EST

Problem solved - I was trying to drag the EditForm.mxml - but it's the EditForm component(as it says in the tutorial)which needs to be dragged - this is found in the custom component folder.
jex 11/04/06 10:19:33 AM EST

OK - I'm a bit new to both Flex and CF, but have been implementing the tutorial fine up until: "Going back to the main application file (mytodolist.mxml), switch to the design view and drag a new panel and inside drag your EditForm component." When I drag the EditForm component onto the panel, nothing happens. Would it be possible to explain exactly what has to be done here? Many thanks.
Francois-Yanick Bourassa 08/09/06 04:21:30 PM EDT

I found myself a bit confused to follow this article as it is a bit out of the real target - which is bringing new people to use Flex and ColdFusion. As a ColdFusion programmer, I found very interesting to try this example with Flex. But after couple paragraphs, started to be confused on which file I was suppose to put the code as Flex is a real new thing for me - I'm sure it will be the same for few of us - if it is not more! We use to read article where editor just put rectangle on source code by page - but this article seems to have a different goal!

I will figure out what was wrong in the code because I think I can but what about newbies!!!

This was my personal feedback!
AJAXWorld News Desk 08/09/06 08:35:47 AM EDT

Flex is a complete set of tools to develop rich Internet cross-platform applications based on the Flash platform. With Flex, you can create applications that not only have the 'wow factor' necessary to please clients and users alike, but the 'usability factor' necessary to make your application a real success.
cfdj news desk 08/08/06 08:29:03 PM EDT

Flex is a complete set of tools to develop rich Internet cross-platform applications based on the Flash platform. With Flex, you can create applications that not only have the 'wow factor' necessary to please clients and users alike, but the 'usability factor' necessary to make your application a real success.
CFDJ News Desk 08/08/06 07:25:22 PM EDT

Flex is a complete set of tools to develop rich Internet cross-platform applications based on the Flash platform. With Flex, you can create applications that not only have the 'wow factor' necessary to please clients and users alike, but the 'usability factor' necessary to make your application a real success.
AJAXWorld News Desk 08/08/06 07:11:51 PM EDT

Flex is a complete set of tools to develop rich Internet cross-platform applications based on the Flash platform. With Flex, you can create applications that not only have the 'wow factor' necessary to please clients and users alike, but the 'usability factor' necessary to make your application a real success.
AJAXWorld News Desk 08/07/06 03:11:03 PM EDT

Flex is a complete set of tools to develop rich Internet cross-platform applications based on the Flash platform. With Flex, you can create applications that not only have the 'wow factor' necessary to please clients and users alike, but the 'usability factor' necessary to make your application a real success.
SYS-CON Australia News Desk 08/07/06 09:34:46 AM EDT

Flex is a complete set of tools to develop rich Internet cross-platform applications based on the Flash platform. With Flex, you can create applications that not only have the 'wow factor' necessary to please clients and users alike, but the 'usability factor' necessary to make your application a real success.
IoT & Smart Cities Stories
By Liz McMillan
The challenges of aggregating data from consumer-oriented devices, such as wearable technologies and smart thermostats, are fairly well-understood. However, there are a new set of challenges for IoT devices that generate megabytes or gigabytes of data per second. Certainly, the infrastructure will have to change, as those volumes of data will likely overwhelm the available bandwidth for aggregating the data into a central repository. Ochandarena discusses a whole new way to think about your next...
Jul. 21, 2018 06:00 PM EDT
By Zakia Bouachraoui
CloudEXPO | DevOpsSUMMIT | DXWorldEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
Jul. 21, 2018 01:00 PM EDT
By Yeshim Deniz
All in Mobile is a place where we continually maximize their impact by fostering understanding, empathy, insights, creativity and joy. They believe that a truly useful and desirable mobile app doesn't need the brightest idea or the most advanced technology. A great product begins with understanding people. It's easy to think that customers will love your app, but can you justify it? They make sure your final app is something that users truly want and need. The only way to do this is by ...
Jul. 21, 2018 02:00 AM EDT
By Liz McMillan
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
Jul. 20, 2018 07:45 PM EDT  Reads: 2,734
By Zakia Bouachraoui
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
Jul. 20, 2018 10:00 AM EDT
By Liz McMillan
DXWorldEXPO LLC announced today that Big Data Federation to Exhibit at the 22nd International CloudEXPO, colocated with DevOpsSUMMIT and DXWorldEXPO, November 12-13, 2018 in New York City. Big Data Federation, Inc. develops and applies artificial intelligence to predict financial and economic events that matter. The company uncovers patterns and precise drivers of performance and outcomes with the aid of machine-learning algorithms, big data, and fundamental analysis. Their products are deployed...
Jul. 18, 2018 12:30 PM EDT
By Yeshim Deniz
Cell networks have the advantage of long-range communications, reaching an estimated 90% of the world. But cell networks such as 2G, 3G and LTE consume lots of power and were designed for connecting people. They are not optimized for low- or battery-powered devices or for IoT applications with infrequently transmitted data. Cell IoT modules that support narrow-band IoT and 4G cell networks will enable cell connectivity, device management, and app enablement for low-power wide-area network IoT. B...
Jul. 11, 2018 08:15 PM EDT
By Pat Romanski
The hierarchical architecture that distributes "compute" within the network specially at the edge can enable new services by harnessing emerging technologies. But Edge-Compute comes at increased cost that needs to be managed and potentially augmented by creative architecture solutions as there will always a catching-up with the capacity demands. Processing power in smartphones has enhanced YoY and there is increasingly spare compute capacity that can be potentially pooled. Uber has successfully ...
Jul. 10, 2018 04:00 PM EDT
By Liz McMillan
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
Jul. 4, 2018 04:45 PM EDT  Reads: 4,337
By Yeshim Deniz
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...
Jul. 3, 2018 03:45 PM EDT  Reads: 3,571
MORE »