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SerializationFilter

Package | mx.rpc.http
Class | public class SerializationFilter
Inheritance | SerializationFilter Object

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

This class is useful for framework developers wishing to plug in or modify the HTTP services to use a new serialization format. This allows you to invoke methods on the service object and control how parameters are mapped to a specific serialiation format such as XML, JSON, etc. The SerializationFilter mechanism allows you to add a new resultFormat as well.

An instance of this class can manage formatting HTTP requests, responses, and converting their parameters. When you use HTTPService or HTTPMultiService, you are usually talking to a server which expects the data to be provided in a specific format - for example, URL encoded values for a type HTML form, XML values or another serialization format such as JSON. SerializationFilter allows you to customize how HTTPService and HTTPMultiService convert an operation's parameters into the body of the HTTP request and how the response is converted into the return value of the operation. Framework developers can introduce a new serialization format to the system by providing a new implementation of the SerializationFilter and use these components and all of the frameworks and tools built on these components without having to know the details of the format itself.

The first thing you do is to extend the SerializationFilter and override one or more of the conversion methods. The filter allows you to turn the ordered list of parameters into a request body, modify the request body, modify the content type used in the request, modify the actual URL used in the request, and convert the response data into the result object returned in the result event of the service.

There are two ways to specify the SerializationFilter for a particular HTTPService, or HTTPMultiService. You can either set the serializationFilter property on the service or you can statically register a SerializationFilter for a new result format. If you use this approach, simply by specifying the resultFormat you can use a pre-registered SerializationFilter. So for example, you might register a SerializationFilter for the "json" type and can then use that filter by setting resultFormat="json".

Note that HTTPService only provides methods which directly take the request body and so does not use the "serializeParameters" method.

Public Methods

| Method | Defined By
--- | --- | ---
|  | deserializeResult(operation:AbstractOperation, result:Object):Object This method takes the result from the HTTP request in a raw format. | SerializationFilter
|  | getRequestContentType(operation:AbstractOperation, obj:Object, contentType:String):String This method is called by the HTTP service just before a call is made. | SerializationFilter
|  | registerFilterForResultFormat(resultFormat:String, filter:SerializationFilter):SerializationFilter [static] This static function is used to register a new SerializationFilter for a particular resultFormat value. | SerializationFilter
|  | serializeBody(operation:AbstractOperation, obj:Object):Object This method is called for all invocations of the HTTP service. | SerializationFilter
|  | serializeParameters(operation:AbstractOperation, params:Array):Object This method is called from the "send" method of the HTTP service invocation to convert the parameters into a request body. | SerializationFilter
|  | serializeURL(operation:AbstractOperation, obj:Object, url:String):String This method is used if you need to take data from the request body object and encode it into the URL string. | SerializationFilter

Method Detail

deserializeResult | () | method

`public function deserializeResult(operation:AbstractOperation, result:Object):Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

This method takes the result from the HTTP request in a raw format. It can convert it to a more fully typed ActionScript object if desired. To make the SerializationFilter more general, you can use the resultType or resultElementType properties of the AbstractOperation provided so your code can dynamically map the incoming request to the type configured in ActionScript as the return type.

Note also that AbstractOperation has a "properties" map which you can use to store additional properties as part of the service invocation in ActionScript to handle the deserialization of a particular type.

Parameters

| `operation:AbstractOperation` — The AbstractOperation which is being invoked.
| `result:Object` — the raw result as returned from the server.

Returns

| `Object` — the converted result which will then be supplied in the result event for the service.

getRequestContentType | () | method |

`public function getRequestContentType(operation:AbstractOperation, obj:Object, contentType:String):String`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

This method is called by the HTTP service just before a call is made. Its role is to choose the contentType used for this request. For many serialization formats, there is a single fixed content type so you might just return that content type here. Since the HTTPService is itself configured with a content type, that value is passed in here and returned by the default implementation. The request body being serialized is also provided with the obj parameter just in case the content type depends on the type of object being sent to the server.

Parameters

| `operation:AbstractOperation` — The AbstractionOperation being invoked.
| `obj:Object` — the body of the HTTP request being serialized
| `contentType:String` — the contentType configured for the operation

Returns

| `String` — the content type to use for this HTTP request.

registerFilterForResultFormat | () | method |

`public static function registerFilterForResultFormat(resultFormat:String, filter:SerializationFilter):SerializationFilter`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

This static function is used to register a new SerializationFilter for a particular resultFormat value. If you call this method once at startup, you can then just specify the resultFormat property of an HTTPService or HTTPMultiService to use that serialization filter to make it easier for developers to specify a format.

Parameters

| `resultFormat:String` — A custom resultFormat name to be associated with the supplied SerializationFilter.
| `filter:SerializationFilter` — The SerializationFilter to register.

Returns

| `SerializationFilter`

serializeBody | () | method |

`public function serializeBody(operation:AbstractOperation, obj:Object):Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

This method is called for all invocations of the HTTP service. It is able to convert the supplied object into a form suitable for placing directly in the HTTP's request body. The default implementation just returns the object passed in as the body without any conversion.

Parameters

| `operation:AbstractOperation` — The AbstractOperation being invoked
| `obj:Object` — the initial body of the HTTP request, either the return value of serializeParameters or the parameter to the sendBody method or the send method of HTTPService.

Returns

| `Object` — the potentially converted body to use in the request.

serializeParameters | () | method |

`public function serializeParameters(operation:AbstractOperation, params:Array):Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

This method is called from the "send" method of the HTTP service invocation to convert the parameters into a request body. The parameters of the original send call are put into the params array. This method converts this set of parameters into to a single object which is used as the data for the HTTP request body. The default implementation produces an object where the keys are the values in the Operation's argumentNames array and the values are the values of the parameters. When using the default implementation, you must set argumentNames to have the same number of elements as the parameters array.

Note that this method is not used if you invoke the HTTP operation using the sendBody method which just takes a single object. In that case, this step is skipped and only the serializeBody method is called.

Parameters

| `operation:AbstractOperation` — The AbstractOperation being invoked.
| `params:Array` — the list of parameters passed to the send method

Returns

| `Object` — the body to be used in the HTTP request

serializeURL | () | method |

`public function serializeURL(operation:AbstractOperation, obj:Object, url:String):String`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 9, AIR 1.1

This method is used if you need to take data from the request body object and encode it into the URL string. It is given the incoming URL as configured on the operation or service. This implementation just returns the incoming URL without any conversion.

Parameters

| `operation:AbstractOperation` — The AbstractOperation being invoked
| `obj:Object` — the URL set on the service or operation
| `url:String`

Returns

| `String` — the potentially modified URL to use for this request.

Wed Nov 15 2017, 09:50 AM +01:00