Passing parameters to an HTTPService

The followig example shows how you can pass parameters to an HTTPService by passing an Object in the HTTPService’s send() method. The remote ColdFusion script is a simple “hello world” type script which accepts a single parameter, “name”, and returns a single parameter, “welcomeMessage”.

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/10/29/passing-parameters-to-an-httpservice/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;
            import mx.events.ValidationResultEvent;
            import mx.utils.StringUtil;

            private function submit_click(evt:MouseEvent):void {
                var result:ValidationResultEvent = stringValidator.validate();
                var params:Object = {};

                lbl.text = "";

                switch (result.type) {
                    case ValidationResultEvent.INVALID:
                        Alert.show(result.message, result.type);
                        break;
                    case ValidationResultEvent.VALID:
                        params["name"] = StringUtil.trim(firstName.text);
                        httpServ.send(params);
                        break;
                }
            }
        ]]>
    </mx:Script>

    <mx:StringValidator id="stringValidator"
            source="{firstName}"
            property="text"
            minLength="2"
            maxLength="{firstName.maxChars}" />

    <mx:HTTPService id="httpServ">
        <mx:resultFormat>flashvars</mx:resultFormat>
        <mx:url>http://www.flash-mx.com/mm/greeting.cfm</mx:url>
        <mx:result>lbl.text = httpServ.lastResult.welcomeMessage;</mx:result>
        <mx:fault>Alert.show(event.toString(), event.type);</mx:fault>
    </mx:HTTPService>

    <mx:ApplicationControlBar dock="true">
        <mx:Form>
            <mx:FormItem label="Name:" required="true"
                    direction="horizontal">
                <mx:TextInput id="firstName"
                    maxChars="20" />
                <mx:Button label="Submit"
                        click="submit_click(event);" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:Label id="lbl" fontSize="32" />

</mx:Application>

View source is enabled in the following example.

By popular request, here is the ColdFusion source code as well.

http://www.flash-mx.com/mm/greeting.cfm

<cfsilent>
<cfsetting enablecfoutputonly="Yes">
<cfif IsDefined("URL.name")><cfset Form.Name = URL.name /></cfif>
<cfif NOT IsDefined("Form.name") OR Len(Trim(Form.Name)) EQ 0>
    <cfset Form.Name = "[Mysterious Stranger]" />
</cfif>
</cfsilent><cfcontent reset="true" /><cfoutput>welcomeMessage=#UrlEncodedFormat("Welcome, "&Form.name)#</cfoutput>
<cfsetting enablecfoutputonly="No">