| Package | flash.net.dns |
| Class | public class DNSResolver |
| Inheritance | DNSResolver  EventDispatcher Object |
| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 2 |
AIR profile support: This feature is supported on
all desktop operating systems, but is not supported on mobile devices. It is partially supported
on AIR for TV devices. You can test for
support at run time using the DNSResolver.isSupported property. See
AIR Profile Support for more information regarding API support across multiple profiles.
You can look up the following types of resource records:
- ARecord: IPv4 address for a host.
- AAAARecord: IPv6 address for a host.
- MXRecord: mail exchange record for a host.
- PTRRecord: host name for an IP address.
- SRVRecord: service record for a service
The following table indicates DNS lookup support on AIR for TV devices. Unsupported requests result in the DNSResolver object dispatching an flash.events.ErrorEvent object.
Record type specified in DNSResolver.lookup()
| Support |
|---|---|
| ARecord | Full support |
| AAAARecord | Full support |
| MXRecord | Not supported |
| PTRRecord | Supported only for IPv4 addresses, not for IPv6 addresses |
| SRVRecord | Not supported |
More examples
Related API Elements
Public Properties
Hide Inherited Public Properties
Show Inherited Public Properties| Property | Defined By | ||
|---|---|---|---|
 | constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | |
| isSupported : Boolean [static] [read-only]
Indicates whether DNS lookups are supported on the client system. | DNSResolver | ||
| prototype : Object [static]
A reference to the prototype object of a class or function object. | Object | |
Public Methods
| Method | Defined By | ||
|---|---|---|---|
Creates a DNSResolver object. | DNSResolver | ||
| addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener
receives notification of an event. | EventDispatcher | |
|
Dispatches an event into the event flow. | EventDispatcher | |
|
Checks whether the EventDispatcher object has any listeners registered for a specific type
of event. | EventDispatcher | |
|
Indicates whether an object has a specified property defined. | Object | |
|
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | |
Looks up a DNS resource record based on a query string. | DNSResolver | ||
|
Indicates whether the specified property exists and is enumerable. | Object | |
|
Removes a listener from the EventDispatcher object. | EventDispatcher | |
|
Sets the availability of a dynamic property for loop operations. | Object | |
|
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | |
|
Returns the string representation of the specified object. | Object | |
|
Returns the primitive value of the specified object. | Object | |
|
Checks whether an event listener is registered with this EventDispatcher object or any of
its ancestors for the specified event type. | EventDispatcher | |
Events
| Event | Summary | Defined By | ||
|---|---|---|---|---|
| [broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active. | EventDispatcher | ||
| [broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive. | EventDispatcher | ||
| Dispatched when an error occurred during a DNS lookup. | DNSResolver | |||
| Dispatched when a DNS look-up is complete. | DNSResolver | |||
Property Detail
isSupported | property |
Constructor Detail
DNSResolver | () | Constructor |
public function DNSResolver()| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 2 |
Creates a DNSResolver object.
Method Detail
lookup | () | method |
public function lookup(host:String, recordType:Class):void| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 2 |
Looks up a DNS resource record based on a query string.
The lookup() method performs a DNS lookup asynchronously.
Listen for the lookup event to get the results of the lookup. Listen for
the error event to receive errors. Results are dispatched in a DNSResolverEvent
object.
To specify the type of resource record to look up, pass the corresponding class
in the recordType parameter. (Pass the class name itself and not a string
containing the class name.)
The content of the query string passed to the method depends on the type of resource record being looked up. The following list illustrates the query string to use for each record type.
| Record type | Query string | Example |
|---|---|---|
| ARecord | host name | "example.com" |
| AAAARecord | host name | "example.com" |
| MXRecord | host name | "example.com" |
| PTRRecord | IP address | "208.77.188.166" |
| SRVRecord | _service._protocol.host. | "_sip._tcp.example.com." |
Parameters
host:String — the query string, such as a host name, IP address, or service locator.
| |
recordType:Class — The class representing the type of DNS resource record to look up.
|
Events
lookup: — dispatched when the lookup is completed successfully.
| |
error: — dispatched when the lookup fails (including when no records exist).
|
Throws
ArgumentError — The host parameter value is not an appropriate query string or the recordType class is not recognized.
|
Related API Elements
Event Detail
error | Event |
Event Object Type:
property ErrorEvent.type =
flash.events.ErrorEventproperty ErrorEvent.type =
flash.events.ErrorEvent.ERROR| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 2 |
Dispatched when an error occurred during a DNS lookup.
Defines the value of thetype property of an error event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object experiencing a network operation failure. |
text | Text to be displayed as an error message. |
lookup | Event |
Event Object Type:
property DNSResolverEvent.type =
flash.events.DNSResolverEventproperty DNSResolverEvent.type =
flash.events.DNSResolverEvent.LOOKUP| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 2 |
Dispatched when a DNS look-up is complete.
Defines the value of thetype property of a lookup event object.
Examples How to use this example
DNSResolverExample.as
The following example shows how to look up the supported types of DNS records:
package
{
import flash.desktop.NativeApplication;
import flash.display.Sprite;
import flash.events.DNSResolverEvent;
import flash.events.ErrorEvent;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.net.dns.AAAARecord;
import flash.net.dns.ARecord;
import flash.net.dns.DNSResolver;
import flash.net.dns.MXRecord;
import flash.net.dns.PTRRecord;
import flash.net.dns.SRVRecord;
import flash.utils.getQualifiedClassName;
public class DNSResolverExample extends Sprite
{
private var resolver:DNSResolver = new DNSResolver();
public function DNSResolverExample()
{
resolver.addEventListener( DNSResolverEvent.LOOKUP, lookupComplete );
resolver.addEventListener( ErrorEvent.ERROR, lookupError );
//Look up records
resolver.lookup( "www.example.com", ARecord );
resolver.lookup( "example.com", AAAARecord );
resolver.lookup( "example.com", MXRecord );
resolver.lookup( "208.77.188.166", PTRRecord );
resolver.lookup( "127.0.0.1", PTRRecord );
resolver.lookup( "2001:1890:110b:1e19:f06b:72db:7026:3d7a", PTRRecord );
resolver.lookup( "_sip._tcp.example.com.", SRVRecord );
resolver.lookup( "www.example.com", ARecord );
this.stage.nativeWindow.activate();
}
private function lookupComplete( event:DNSResolverEvent ):void
{
trace( "Query string: " + event.host );
trace( "Record type: " + flash.utils.getQualifiedClassName( event.resourceRecords[0] ) +
", count: " + event.resourceRecords.length );
for each( var record in event.resourceRecords )
{
if( record is ARecord ) trace( record.name + " : " + record.address );
if( record is AAAARecord ) trace( record.name + " : " + record.address );
if( record is MXRecord ) trace( record.name + " : " + record.exchange + ", " + record.preference );
if( record is PTRRecord ) trace( record.name + " : " + record.ptrdName );
if( record is SRVRecord ) trace( record.name + " : " + record.target + ", " + record.port +
", " + record.priority + ", " + record.weight );
}
}
private function lookupError( error:ErrorEvent ):void
{
trace("Error: " + error.text );
}
}
}
Mon Nov 28 2011, 06:48 AM -08:00