DIY Flex

Do-It-Yourself (DIY) FlexIan Grasshoff – Waupaca County

Dan McFarlane – UW Stevens Point

Goal:

To provide a basic guide and the corresponding resources to help attendees get started using the Esri Flex Application Programming Interface (API) in conjunction with ArcGIS Server.

Overview• What is Flex and How does it Work?• Why use Flex?• Why Do-It-Yourself (DIY)?• Getting Started• Learning Pathways• Brief Examples• Lessons Learned• Resources• Questions

What is Flex?

– Flex is a Software Development Kit (SDK) for building expressive web applications that deploy consistently on all major browsers

– Flex was created to make it easier for developers to construct applications using Flash platform

– Two core pieces: MXML and ActionScript – February 2008 Adobe released Flex 3 SDK under open source

Mozilla Public License– Applications can be developed using Eclipse Integrated

Development Environment (IDE) (free) or Adobe Flash Builder ($$)

Source: http://www.adobe.com/products/flex

MXML ActionScript

Flex Class Library

Flex SDK

Flash Builder IDE

What is MXML?

• MXML (no official meaning)– XML based markup language– Used for laying out user interface

components and data sources– Similar to HTML but more structured and richer set of tags (about 100)– Complies to .swf file (small web format, opens with Flashplayer) or .air

Simple Example:

<mx:Canvas id="siteTitle" width="239.5" height="46" top="46" left="168“ backgroundAlpha="1.0" styleName="titleIconCanvas" borderSides="top,right" cornerRadius="0" includeIn="State1">

<mx:Label text="Radon Test Results" fontWeight="bold" fontSize="22“ left="-2" top="1“ fontFamily="CourierNew" width="100%" height="25“ textAlign="center" color="#1f5c5b"/>

<mx:Label text="Waupaca County, Wisconsin" fontWeight="bold" fontSize="12“ fontStyle="italic" left="0" top="23" fontFamily="Verdana" width="200" height="20“ textAlign="left" textDecoration="none" color="#000000"/></mx:Canvas>

Flash Builder IDEFlex SDK

MXML

What is Action Script?

• ActionScript (Current Version: 3.0)– Object-oriented programming language

developed by Macromedia– ECMAScript, which means syntax is similar to

Javascript– ActionScript makes things happen! MXML and ActionScript go together

– Complies to .swf file (small web format, opens with Flashplayer)

Simple Example:<![CDATA[

import mx.controls.Alert;private function myFunction(txt:String):void{

Alert.show(txt,”My Alert”,Alert.OK);}

]]><mx:VBox width=“500” top=“10” left=“10”>

<mx:TextInput id=“myText” width=“95%”/><mx:Button id=“myButton” click=“myFunction(myText.text)” label=“click me”/>

</mx:VBox>

Flash Builder IDEFlex SDK

ActionScript

Example Link

How Flex Works

Flash Builder IDE

Flex SDK

MXML ActionScript

Flex Class Library

.swf

Flash Player

Client Web Browser

Data Data

Web Server

Flex Remote Objects

J2EE/Cold Fusion/PHP/.NET

Existing Applications and Infrastructure

XML/HTTP, REST, SOAP Web Services

.air

AIR Runtime on Desktop Computer

Flex & ArcGIS Server

Web Server

XML/HTTP, REST, SOAP Web Services

Flash Player

Client Web BrowserD

ata

Data

ArcGIS ServerServer Object Manager (SOM) and Server Object Container (SOC)

SDEGeodatabase

FileGeodatabase

Why Use Flex?

• Pros– Tons of Core Components (About 100)– Large User Base (especially among GIS community)– An easy to use integrated development environment (IDE),

aka Flash Builder 4 (previous version is Flex Builder 3)– Polished visual appeal, slick animation effects– MXML/ActionScript 3.0 very similar to JavaScript so it’s

fairly easy to learn– Fast Deployment– Esri has made it easy to use Flex with ArcGIS Server– Lots of online resources

Why Use Flex?Cont.

• Cons– Database access isn’t easy as it could be (but it is

possible)– Integration with Microsoft .NET solutions is

complicated (WebOrb)– Requires Adobe Flash Player to be installed on client

(Adobe claims 99.5% of web clients in US/Canada have ver. 10 installed)

– Applications can be resource intensive– Doesn’t work well on mobile devices– Another new programming language to learn

Why DIY?

• Pros– Save $$$ (no vendor contracts)– No Vendor Lock-in– Maintain future applications in-house– Quicker adaptation of new technology– Flexibility to do what you want, when you want– Gain the knowledge to evaluate vendor products (if you choose to

purchase services in the future)– Springboard to other programming languages

• Cons– Takes time (which costs $$)– Learning curve (if you build from scratch)– Just one more thing to learn/maintain

Learning Pathways

• Flex in a Week Videos• ArcGIS Sample Flex Viewer Application

– Sample Flex Viewer 2.2– Sample Flex Viewer 1.3

• ArcGIS Flex API Samples (access from ArcGIS Resource Center)

• Browse/Download Code Gallery Samples • Modify Code Gallery Samples• Build your own widget and/or modify Sample Flex

Viewer• Create your own custom site from scratch (if deemed

necessary)

Getting Started

• Quick and Easy– Requires access to AGS services (you can use Esri Services

for free)– Download Esri Sample Flex Viewer Application (ArcGIS

Resource Center)– Modify Sample Flex Viewer base config.xml file to point to

ArcGIS Server services– Modify widget config.xml files

Getting Started

• More Involved– Access to ArcGIS Server services (you can use Esri Services

for free)– Download Esri Sample Flex Viewer Application (ArcGIS

Resource Center) source code– Download latest Esri Flex API source code– Download Adobe Flash Builder 4 (Free 60-day trial)

• Flash Builder 4 Premium: $699 ($299.00 for upgrade from previous ver.)

• Flash Builder 4 Standard: $249 ($99.00 for upgrade from previous ver.)

– Setup Flex Project (import source code, setup config.xml files)

– Compile and test the application

Brief Examples

• Example 1: ArcGIS Viewer for Flex

• Example 2: Custom Widgets

• Example 3: Custom Flex Application

Brief Examples

• Example 1: ArcGIS Viewer for Flex– Ready to deploy GIS Web client for ArcGIS Server– Configurable, so you can easily add tools & data without

programming

ArcGIS Viewer for Flex

– Config.xml files

Titles, logos, start up page, application color

Overview map, navigation tools, etc

Map content (basemaps & operational layers)• must reference a published map

service

GIS client functionality

Brief ExamplesArcGIS Viewer for Flex

– Config.xml files

• Controls appearance• Functionality• Data Content• No need to compile application

Brief ExamplesArcGIS Viewer for Flex

– Extend functionality with widgets from ESRI community

Brief ExamplesArcGIS Viewer for Flex

• Ready-to-deploy widgets

Brief ExamplesArcGIS Viewer for Flex

Example Link

Brief ExamplesCustom Widgets

Custom Widgets Example Link

• Custom Sample Flex Viewer Widgets– Use the Esri BaseWidget Class– Plug right into Sample Flex Viewer Application– Just copy/paste any existing widget and modify as needed– Modify the config.xml to include your new widget!

Brief ExamplesCustom Application

Custom Flex Application Example Link

• Custom Flex Application– Goal: create a streamlined, simplified Flex application (started

this prior to the release of Sample Flex Viewer 2.2) for viewing Radon Test Data

– Created with the idea to reuse the base code for future applications

– Started small, grew more complex with each end-user review– Approx. 160 hours to build (this was mainly due to fact that I

was learning as I went)– Learned basic object oriented programming through the

process

Lessons Learned

• Flex in a week video series: great starting point• Document (this can be as simple as good comments in your code)

• Research: chances are someone else might have encountered a similar problem

• Make your code as re-usable as possible (very difficult)• Look into “FlashVars”• Flex coupled with PHP provides even more functionality• Share your code, especially if you “borrow” heavily from

others

Resources• Flex

– Tour de Flex (http://www.adobe.com/devnet/flex/tourdeflex.html)

– Flex in a Week Videos (http://www.adobe.com/devnet/flex/videotraining.html)

– Flex Developer Center (http://www.adobe.com/devnet/flex.html)

– Flex Cookbook(http://cookbooks.adobe.com/flex)

– Flex Examples (http://blog.flexexamples.com)– Balsamiq (http://balsamiq.com/)– Stack Overflow (http://stackoverflow.com/)

Resources Cont.• ArcGIS Server Flex API

– ArcGIS Server Blog (http://blogs.esri.com/Dev/blogs/arcgisserver/default.aspx)

– ArcGIS API for Flex (http://help.arcgis.com/en/webapi/flex/index.html)

– ArcGIS.com Gallery(http://www.arcgis.com/home/gallery.html)

– ArcGIS API 1.3 Code Gallery: Moved to ArcScripts (http://arcscripts.esri.com)

• API 1.3 code is still very useful!

Questions?

[email protected]

[email protected]