.. _Using_WSDL:

**********
Using WSDL
**********

.. index:: WSDL
.. index:: Web Service Definition Language

`WSDL` (Web Service Definition Language) is an `XML` based document
which described a set of Web Services either based on `SOAP` or
`XML/RPC`.
By using a `WSDL` document it is possible to describe, in a formal way,
the interface to any Web Services. The `WSDL` document contains the
end-point (URL to the server offering the service), the `SOAPAction`
(needed to call the right routine), the procedure names and a
description of the input and output parameters.

`AWS` provides two tools to work with `WSDL` documents:

*ada2wsdl*

  .. index:: ada2wsdl

  which creates a `WSDL` document from an Ada package spec.

*wsdl2aws*

  .. index:: wsdl2aws

  which create the interfaces
  to use a Web Service or to implement Web Services. With this tool the
  `SOAP` interface is completely abstracted out, users will deal only
  with `Ada` API. All the `SOAP` marshaling will be created
  automatically.

.. _Creating_WSDL_documents:

Creating WSDL documents
=======================

.. index:: ada2wsdl

Note that this tool is based on `ASIS`.

.. _Using_ada2wsdl:

Using ada2wsdl
--------------

`ada2wsdl` can be used on any Ada spec file to generated a
`WSDL` document. The Ada spec is parsed using `ASIS`.

.. highlight:: sh

The simplest way to use it is::

 $ ada2wsdl simple.ads

.. highlight:: ada

Given the following Ada spec file::

 package Simple is
    function Plus (Value : in Natural) return Natural;
 end Simple;

.. highlight:: xml

It will generate the following `WSDL` document::

 <?xml version="1.0" encoding="UTF-8"?>
 <wsdl:definitions name="Simple"
    targetNamespace="http://soapaws/Simple_def/"
    xmlns:tns="http://soapaws/Simple_def/"
    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
    xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/"
    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
    xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:n1="http://soapaws/Standard_pkg/"
    xmlns:n2="http://soapaws/Simple_pkg/">

    <!-- Generated by AWS/Ada2WSDL v1.3.1
         on Tuesday 25 November 2014 at 11:02:44 -->

    <wsdl:message name="Plus_Request">
       <wsdl:part name="Value" type="xsd:int"/>
    </wsdl:message>

    <wsdl:message name="Plus_Response">
       <wsdl:part name="Result" type="xsd:int"/>
    </wsdl:message>

    <wsdl:portType name="Simple_PortType">
       <wsdl:operation name="Plus">
          <wsdl:input message="tns:Plus_Request"/>
          <wsdl:output message="tns:Plus_Response"/>
       </wsdl:operation>
    </wsdl:portType>

    <wsdl:binding name="Simple_Binding" type="tns:Simple_PortType">
       <soap:binding style="rpc"
          transport="http://schemas.xmlsoap.org/soap/http"/>

       <wsdl:operation name="Plus">
          <soap:operation soapAction="Plus"/>
          <wsdl:input>
             <soap:body
                encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
                namespace="http://soapaws/Simple_def/"
                use="encoded"/>
          </wsdl:input>
          <wsdl:output>
             <soap:body
                encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
                namespace="http://soapaws/Simple_def/"
                use="encoded"/>
          </wsdl:output>
       </wsdl:operation>
    </wsdl:binding>

    <wsdl:service name="Simple_Service">
       <wsdl:port name="Simple_Port" binding="tns:Simple_Binding">
          <soap:address location="http://.../"/>
       </wsdl:port>
    </wsdl:service>
 </wsdl:definitions>

The value of the `name` attribute in the `description` node is
the name of the `WSDL` document (the name of the
Ada spec package). On the `portType` section we have the
description of the Ada **Plus** function. Something important to note
is that in Ada a function does not have a named return parameter,
:file:`ada2wsdl` use **Result** for the response. Both the input and
output parameter are mapped to `SOAP` `xsd:int` type.

Note that the `SOAP` address generated by default (http://.../)
must be edited manually or specified using :file:`ada2wsdl`'s -a
option.

This is of course a very simple example. `ada2wsdl` does support lot
more complex specs and will map Ada records, arrays, enumerations,
derived types to a corresponding `XML` schema definition. See
section below for a description of the mapping.

.. _Ada_mapping_to_WSDL:

Ada mapping to WSDL
-------------------

`ada2wsdl` parse Ada records, arrays, derived types, enumerations,
procedures and functions and generate the corresponding `WSDL`
document. In this section we describe the mapping between Ada and
`WSDL`.

*Integer*
  Mapped to **xsd:int**.

*Float*
  Mapped to **xsd:float**.

*Long_Float*
  Mapped to **xsd:double**

*Long_Long_Float*
  Mapped to **xsd:double**, not supported by SOAP, mapped
  for convenience but precision cannot be guaranteed.

*Boolean*
  Mapped to **xsd:boolean**

*String*
  Mapped to **xsd:string**

*Unbounded_String*
  Mapped to **xsd:string**, note that Unbounded_String should be used
  only inside a record for full interoperability. This is a current limitation.

.. highlight:: xml

*Character*
  Mapped to a Character schema definition::

   <simpleType name="Character">
     <restriction base="xsd:string">
       <length value="1"/>
     </restriction>
   </simpleType>

*Ada.Calendar.Time*
  Mapped to **xsd:dateTime**

*SOAP.Utils.SOAP_Base64*
  Mapped to **xsd:base64Binary**. `SOAP.Utils.SOAP_Base64` is a
  subtype of string which is is recognized by `ada2wsdl` to
  generate the proper SOAP type.

*SOAP.Types.Byte*
  Mapped to **xsd:byte**. `SOAP.Types.Byte` is a type which is
  recognized by `ada2wsdl` to generate the proper SOAP type.

*SOAP.Types.Short*
  Mapped to **xsd:short**. `SOAP.Types.Short` is a type which is
  recognized by `ada2wsdl` to generate the proper SOAP type.

*SOAP.Types.Long*
  Mapped to **xsd:long**. `SOAP.Types.Long` is a type which is
  recognized by `ada2wsdl` to generate the proper SOAP type.

*SOAP.Types.Unsigned_Byte*
  Mapped to **xsd:unsignedByte**. `SOAP.Types.Unsigned_Byte` is a
  type which is recognized by `ada2wsdl` to generate the proper SOAP type.

*SOAP.Types.Unsigned_Short*
  Mapped to **xsd:unsignedShort**. `SOAP.Types.Unsigned_Short` is a
  type which is recognized by `ada2wsdl` to generate the proper SOAP type.

*SOAP.Types.Unsigned_Int*
  Mapped to **xsd:unsignedInt**. `SOAP.Types.Unsigned_Int` is a
  type which is recognized by `ada2wsdl` to generate the proper SOAP type.

*SOAP.Types.Unsigned_Long*
  Mapped to **xsd:unsignedLong**. `SOAP.Types.Unsigned_Long` is a
  type which is recognized by `ada2wsdl` to generate the proper SOAP type.

.. highlight:: ada

*Derived types*
  Mapped to a type schema definition::

   type Number is new Integer;

  .. highlight:: xml

  is defined as::

   <simpleType name="Number" targetNamespace="http://soapaws/WSDL_C_pkg/">
     <restriction base="xsd:int"/>
   </simpleType>

.. highlight:: ada

*Derived types with constraints*
  Mapped to a type schema definition with minInclusive and maxInclusive
  attributes::

   type Number is new Integer range 1 .. 9345;

  .. highlight:: xml

  is defined as::

   <simpleType name="Number" targetNamespace="http://soapaws/WSDL_C_pkg/">
     <restriction base="xsd:int">
       <xsd:minInclusive value=" 1"/>
       <xsd:maxInclusive value=" 9345"/>
     </restriction>
   </simpleType>

   Or for a string::

   .. highlight:: ada

   type Code is String (1 .. 10);

  .. highlight:: xml

  is defined as::

   <simpleType name="Code" targetNamespace="http://soapaws/WSDL_C_pkg/">
     <xsd:restriction base="xsd:string">
       <xsd:Length value="10"/>
     </xsd:restriction>
   </simpleType>

.. highlight:: ada

*User's types*
  Mapped to a type schema definition with minInclusive and
  maxInclusive attributes::

   type Small is range 1 .. 10;

  .. highlight:: xml

  is defined as::

   <simpleType name="Small" targetNamespace="http://soapaws/WSDL_C_pkg/">
     <restriction base="xsd:byte">
       <xsd:minInclusive value=" 1"/>
       <xsd:maxInclusive value=" 10"/>
     </restriction>
   </simpleType>

.. highlight:: ada

*Modular types*
  Mapped to an unsigned type with an optional maxInclusive attribute::

   type Count is mod 14;

  .. highlight:: xml

  is defined as::

   <simpleType name="Count" targetNamespace="http://soapaws/WSDL_C_pkg/">
     <xsd:restriction base="xsd:unsignedByte">
       <xsd:maxInclusive value=" 13"/>
     </xsd:restriction>
   </simpleType>

.. highlight:: ada

*Enumerations*
  Mapped to an enumeration schema definition. For example::

   type Color is (Red, Green, Blue);

  .. highlight:: xml

  is defined as::

   <simpleType name="Color">
     <restriction base="xsd:string">
       <enumeration value="Red"/>
       <enumeration value="Green"/>
       <enumeration value="Blue"/>
     </restriction>
   </simpleType>

.. highlight:: ada

*Records*
  Mapped to a struct schema definition. For example::

   type Rec is record
      A : Integer;
      B : Float;
      C : Long_Float;
      D : Character;
      E : Unbounded_String;
      F : Boolean;
   end record;

  .. highlight:: xml

  is defined as::

   <complexType name="Rec">
     <all>
       <element name="A" type="xsd:int"/>
       <element name="B" type="xsd:float"/>
       <element name="C" type="xsd:double"/>
       <element name="D" type="tns:Character"/>
       <element name="E" type="xsd:string"/>
       <element name="F" type="xsd:boolean"/>
     </all>
   </complexType>

.. highlight:: ada

*Arrays*
  Mapped to an array schema definition. For example::

   type Set_Of_Rec is array (Positive range <>) of Rec;

  .. highlight:: xml

  is defined as::

   <xsd:complexType name="Set_Of_Rec">
     <xsd:sequence>
        <xsd:element name="x" type="n1:Rec"
             minOccurs="0" maxOccurs="unbounded"/>
     </xsd:sequence>
   </xsd:complexType>

  A SOAP encoded format can be generated with the -sea option:

   <complexType name="Set_Of_Rec">
     <complexContent>
       <restriction base="soap-enc:Array">
         <attribute ref="soap-enc:arrayType" wsdl:arrayType="tns:Rec[]"/>
       </restriction>
     </complexContent>
   </complexType>

.. highlight:: ada

*Array inside a record*
  This part is a bit delicate. A record field must be constrained but a
  `SOAP` arrays is most of the time not constrained at all. To
  support this `AWS` use a safe access array component. Such a type
  is built using a generic runtime support package named
  `SOAP.Utils.Safe_Pointers`. This package implements a reference
  counter for the array access and will release automatically the memory
  when no more reference exists for a given object.

  For example, let's say that we have an array of integer that we want
  to put inside a record::

   type Set_Of_Int is array (Positive range <>) of Integer;

  The first step is to create the safe array access support::

   type Set_Of_Int_Access is access Set_Of_Int;

   package Set_Of_Int_Safe_Pointer is
     new SOAP.Utils.Safe_Pointers (Set_Of_Int, Set_Of_Int_Access);

  Note that the name `Set_Of_Int_Safe_Pointer` (*<type>_Safe_Pointer*)
  is mandatory (and checked by :file:`ada2wsdl`) to achieve
  interoperability with :file:`wsdl2aws`. :ref:`Working_with_WSDL_documents`.

  From there the safe array access can be placed into the record::

   type Complex_Rec is record
      SI : Set_Of_Int_Safe_Pointer.Safe_Pointer;
   end record;

  To create a Safe_Pointer given a `Set_Of_Int` one must use
  `Set_Of_Int_Safe_Pointer.To_Safe_Pointer` routine. Accessing
  individual items is done with `SI.Item (K)`.

  .. highlight:: xml

  These Ada definitions are fully recognized by :file:`ada2wsdl` and will
  generate standard array and record `WSDL` definitions as seen above::

   <xsd:complexType name="Set_Of_Int">
     <xsd:sequence>
        <xsd:element name="x" type="xsd:int"
             minOccurs="0" maxOccurs="unbounded"/>
     </xsd:sequence>
   </xsd:complexType>

   <complexType name="Complex_Rec">
     <all>
       <element name="SI" type="tns:Set_Of_Int"/>
     </all>
   </complexType>

*Array as routine parameter*
  When an array is passed as parameter to a `SOAP` routine it is also
  require to create a corresponding Safe_Pointer when using
  `Document/Literal` binding and using a user's type package (see
  `-types` and '`-spec` `wsdl2aws` options). This is needed for the
  `AWS` generated code to handle this routine. Even if required in a
  very specific case it is never an error to declare such Safe_Pointer
  for an array.

  For example::

   type Set_Of_Int is array (Positive range <>) of Integer;

   procedure Call (Values : Set_Of_Int);

  Then the following declarations are required::

   type Set_Of_Int_Access is access Set_Of_Int;

   package Set_Of_Int_Safe_Pointer is
     new SOAP.Utils.Safe_Pointers (Set_Of_Int, Set_Of_Int_Access);

.. _ada2wsdl:

.. highlight:: ada

ada2wsdl
--------

::

 Usage: ada2wsdl [options] ada_spec

`ada2wsdl` options are:

*-a url*
  Specify the `URL` for the Web Server address. Web Services will be
  available at this address. A port can be specified on the `URL`,
  `http://server[:port]`. The default value is `http://.../`.

*-f*
  Force creation of the `WSDL` file. Overwrite exiting file
  with the same name.

*-doc*
  Generate document's style binding (default is RPC)

*-lit*
  Generate literal's style binding (default is encoded)

*-I path*
  Add path option for the `ASIS` compilation step. This option can
  appear any number of time on the command line.

*-n name*
  Specify the schema name space root name. The default value is "soapaws".

*-noenum*
  Do not generate `WSDL` representation for Ada enumerations, map
  them to standard string. :ref:`Ada_mapping_to_WSDL`.

*-sea*
  Generate SOAP encoded format for array definitions. This option is
  kept for compatibility reason, but the schema based definition for
  arrays is recommended for better interoperability.

*-o file*
  Generate the `WSDL` document into file.

*-P proj*
  The project file to use for building the spec.

*-q*
  Quiet mode (no output)

*-s name*
  Specify the Web Service name for the `WSDL` document, by default
  the spec package's name is used.

*-t path*
  Specify the path to the tree file directory to use. This is needed when
  using a project file the object directory is not the current directory.

*-d*
  Do not generate date/time in WSDL.

*-v*
  Verbose mode, display the parsed spec.

.. _:file:`ada2wsdl`_limitations:

ada2wsdl limitations
---------------------

.. index:: ada2wsdl limitations

* Do not handle constrained arrays into a records.

* Unbounded_String are supported with full interoperability only inside a record.

* Only unconstrained arrays are supported

* Arrays with multiple dimensions not supported

.. _Working_with_WSDL_documents:

Working with WSDL documents
===========================

.. _Client_side_(stub):

Client side (stub)
------------------

.. index:: WSDL, Client

This section describe how to use a Web Service. Let's say that we want
to use the Barnes & Noble Price Quote service. The WSDL document for
this service can be found at
`http://www.xmethods.net/sd/2001/BNQuoteService.wsdl <http://www.xmethods.net/sd/2001/BNQuoteService.wsdl>`_. In summary
this document says that there is a service named `getPrice`
taking as input a string representing the ISBN number and returning
the price as floating point.

The first step is to generate the client interface (stub)::

 $ wsdl2aws -noskel http://www.xmethods.net/sd/2001/BNQuoteService.wsdl

This will create many files, the interesting one at this point is
:file:`bnquoteservice-client.ads`, inside we have::

 function getPrice (isbn : in String) return Float;
 --  Raises SOAP.SOAP_Error if the procedure fails

Let's call this service to find out the price for
*The Sword of Shannara Trilogy* book::

 with Ada.Text_IO;
 with BNQuoteService.Client;

 procedure Price is
    use Ada;

    ISBN : constant String := "0345453751";
    --  The Sword of Shannara Trilogy ISBN

    package LFIO is new Text_IO.Float_IO (Float);

 begin
    Text_IO.Put_Line ("B&N Price for The Sword of Shannara Trilogy");
    LFIO.Put (BNQuoteService.Client.getPrice (ISBN), Aft => 2, Exp => 0);
 end Price;

That's all is needed to use this Web Service. This program is fully
functional, It is possible to build it and to run it to get the answer.

.. _Server_side_(skeleton):

Server side (skeleton)
----------------------

.. index:: WSDL, Server

Building a Web Service can also be done from a `WSDL` document. Let's
say that you are Barnes & Noble and that you want to build Web Service
`getPrice` as described in the previous section.

You have created the `WSDL` document to specify the service spec.
From there you can create the skeleton::

 $ wsdl2aws -nostub http://www.xmethods.net/sd/2001/BNQuoteService.wsdl

This will create many files, the interesting one here is
:file:`bnquoteservice-server.ads`, inside we have::

 Port : constant := 80;

 generic
    with function getPrice (isbn : in String) return Float;
 function getPrice_CB
   (SOAPAction : in String;
    Payload    : in SOAP.Message.Payload.Object;
    Request    : in AWS.Status.Data) return AWS.Response.Data;

This is a `SOAP AWS`'s callback routine that can be instantiated
with the right routine to retrieve the price of a book given its ISBN
number. A possible implementation of such routine could be::

 function getPrice (isbn : in String) return Float is
 begin
    if isbn = "0987654321" then
       return 45.0;
    elsif ...
 end getPrice;

 function SOAP_getPrice is new BNQuoteService.Server.getPrice_CB (getPrice);

`SOAP_getPrice` is a `SOAP AWS`'s callback routine (i.e. it is not
a standard callback). To use it there is different solutions:

*Using SOAP.Utils.SOAP_Wrapper*
  This generic function can be used to translate a standard callback
  based on `AWS.Status.Data` into a `SOAP` callback routine::

   function getPrice_Wrapper is new SOAP.Utils.SOAP_Wrapper (SOAP_getPrice);

  The routine `getPrice_Wrapper` can be used as any other AWS's
  callback routines. Note that inside this wrapper the `XML` payload is
  parsed to check the routine name and to retrieve the `SOAP`
  parameters. To call this routine the payload needs to be parsed (we
  need to know which routine has be invoked). In this case we have
  parsed the `XML` payload twice, this is not efficient.

*Building the wrapper yourself*
  This solution is more efficient if there is many `SOAP`
  procedures as the payload is parsed only once::

   function CB (Request : in Status.Data) return Response.Data is
      SOAPAction : constant String := Status.SOAPAction (Request);
      Payload    : constant SOAP.Message.Payload.Object :=
        SOAP.Message.XML.Load_Payload
          (AWS.Status.Payload (Request), Schema => BNQuoteService.Schema);
      Proc       : constant String :=
        SOAP.Message.Payload.Procedure_Name (Payload);
   begin
      if SOAPAction = "..." then

         if Proc = "getPrice" then
            return SOAP_getPrice (SOAPAction, Payload, Request);
         elsif ...
            ...
         end if;

      else
         ...
      end if;

Note that the port to be used by the AWS server is described into the
server spec.

.. _wsdl2aws:

wsdl2aws
--------

.. index:: wsdl2aws

::

  Usage: wsdl2aws [options] <file|URL>

It is possible to pass a `WSDL` file or direct :file:`wsdl2aws` to
a `WSDL` document on the Web by passing it's `URL`.

`wsdl2aws` options are:

*-q*
  Quiet mode (no output)

*-d*
  Do not generate date/time in Ada comment.

*-debug*
  Generate debug code. Will output some information about the payload to
  help debug a Web Service.

*-a*
  Generate using Ada style names. For example `getPrice` will be converted
  to `Get_Price`. This formatting is done for packages, routines and formal
  parameters.

*-f*
  Force creation of the file. Overwrite any exiting files with the same
  name.

*-e URL*
  Specify the default endpoint to use instead of the one found in the
  WSDL document.

*-s*
  Skip non supported `SOAP` routines. If `-s` is not used,
  `wsdl2aws` will exit with an error when a problem is found while
  parsing the `WSDL` document. This option is useful to skip
  routines using non supported types and still be able to compile the
  generated files.

*-o name*
  Specify the name of the local `WSDL` document. This option can be used
  only when using a Web `WSDL` document (i.e. passing an URL to
  `wsdl2aws`).

*-p name*
  Specify a name prefix for all SOAPActions defined in the `WDSL`.
  This option can be used when multiple WSDL generated callback are to
  be used together and some of the `WSDL` may have the same name.

*-doc*
  Handle document style binding as RPC ones. This is sometimes needed
  because some `WSDL` document specify a document style binding even
  though the service behave like an RPC one.

*-v*
  Verbose mode, display the parsed spec.

*-v -v*
  Verbose mode, display the parsed spec and lot of information while
  parsing the `WSDL` document tree.

*-wsdl*
  Add `WSDL` document as comment into the generated root unit.

*-cvs*
  Add CVS Id tag in every generated file.

*-nostub*
  Do not generated stubs, only skeletons are generated.

*-noskel*
  Do not generated skeletons, only stubs are generated.

*-cb*
  Generate a `SOAP` dispatcher callback routine for the
  server. This dispatcher routine contains the code to handle all the
  operations as described in the `WSDL` document. You need also to
  specify the `-spec` and/or `-types` options, see below.

*-x operation*
  Add `operation` to the list of `SOAP` operations to skip during the
  code generation. It is possible to specify multiple `-x` options on the
  command line.

*-spec spec*
  Specify the name of the spec containing the Ada implementation of the
  `SOAP` routines. This is used for example by the `-cb` option above
  to instantiate all the server side `SOAP` callbacks used by the main
  `SOAP` dispatcher routine. If `-types` is not specified, the
  type definitions are also used from this spec.

*-types spec*
  Specify the name of the spec containing the Ada types (record, array) used by
  `SOAP` routines specified with option `-spec`. If `-spec` is
  not specified, the spec definitions are also used from this spec.

*-main filename*
  Specify the name of the server's procedure main to generate. If
  file :file:`<filename>.amt` (Ada Main Template) is present, it uses this
  template file to generate the main procedure. The template can
  reference the following variable tags:

  *SOAP_SERVICE*
      The name of the service as described into the `WSDL`
      document. This tag can be used to include the right units::

       with @_SOAP_SERVICE_@.Client;
       with @_SOAP_SERVICE_@.CB;

  *SOAP_VERSION*
      The AWS's SOAP version.

  *AWS_VERSION*
      The AWS's version.

  *UNIT_NAME*
      The name of the generated unit. This is the name of the procedure that
      will be created::

       procedure @_UNIT_NAME_@ is
       begin
          ...

*-n name*
  Specify the schema name space root name. The default value is "soapaws".

*-proxy name|IP*
  Use this proxy to access the `WSDL` document and generate code to access
  to these Web Services via this proxy. The proxy can be specified by
  its DNS name or IP address.

*-pu name*
  User name for the proxy if proxy authentication required.

*-pp password*
  User password for the proxy if proxy authentication required.

*-timeouts [timeouts | connect_timeout,send_timeout,receive_timeout ]*
  Set the timeouts for the SOAP connection. The timeouts is either a
  single value used for the connect, send and receive timeouts or three
  values separated by a colon to set each timeout independently.

.. _wsdl2aws_behind_the_scene:

wsdl2aws behind the scene
-------------------------

The `wsdl2aws` tool read a `WSDL` document and creates a root
package and a set of child packages as described below:

*<root>*
  This is the main package, it contains eventually the full `WSDL` in
  comment and the description of the services as read from the `WSDL`
  document.

*<NS>.<type>_type_pkg*
  Contains all the type definitions for non standard Ada types. In
  these packages we find for example the definition of the records and
  the operation to convert them to/from SOAP objects. The types
  defined here have possible constraints like range attribute and/or
  Dynamic_Predicate aspects for Pattern and/or Length WSDL attribute.

  The root package <NS> is the name-space of the actual type. This
  ensure that no type name clash will happen. Those packages are
  generally not directly withed.

*<root>.Types*
  This package contains the definitions of the types which are not `SOAP`
  base types. We find here the definitions of the `SOAP` structs
  and arrays with routines to convert them between the Ada and `SOAP` type
  model. A subtype definition is also created for every routine's
  returned type. In fact, all definitions here are only alias or
  renaming of types and/or routines generated in other packages rooted
  with a name-space as described above. This package is the one that
  user's should import to gain the visibility of types definitions.

  This package also contains the schema object which must be used when
  calling a Web service or parsing a payload.

*<root>.Client*
  All spec to call Web Services.

*<root>.Server*
  All spec to build Web Services. These specs are all generic and must
  be instantiated with the right routine to create the web services.

*<root>.CB*
  The `SOAP` dispatcher callback routine.

.. _wsdl2aws_limitations:

wsdl2aws limitations
--------------------

.. index:: wsdl2aws limitations

It is hard to know all current limitations as the `WSDL` and
`SOAP` world is quite complex. We list there all known limitations:

* Some `SOAP` base types are not supported : *date, time, xsd:hexBinary, decimal*. All these are easy to add (except decimal), it is just not
  supported with the current version.

* Multi-dimension arrays are not supported.

* abstract types are not supported.

* SOAP MIME attachments are not supported.

* WSDL type inheritance not supported.

* The Document/Encoded SOAP messages' style is not supported

* complexType with xs:choice are only supported with a single occurence
  of each choice.

.. _awsascb:

awsascb
-------

.. index:: awsascb

The awsascb (AWS Aggregate Server Callback) tool can be used to
aggregate multiple SOAP callback together. That is, after generated
multiple SOAP callback with wsdl2aws it may be needed to create a
single server handling all the services. This tools is designed for
this.

::

  Usage: awsascb <root1> <root2>

This is no option to for this tool. The `root` parameters are the
`wsdl2aws` generated root service name unit. This tool generates a unit named
`agg_server_cb` which contains a SOAP callback and a dispatcher
to be used by the server main. Here is the spec::

 --  DO NOT EDIT : generated by awsasc

 with AWS.Response;
 with AWS.Status;

 with SOAP.Dispatchers.Callback;
 with SOAP.Message.Payload;
 with SOAP.WSDL.Schema;

 package Agg_Server_CB is

    use AWS;
    use SOAP;

    pragma Style_Checks (Off);

    type Handler is new SOAP.Dispatchers.Callback.Handler with null record;

    overriding function Schema
      (Dispatcher : Handler;
       SOAPAction : String)
       return WSDL.Schema.Definition;

    function Create
      (HTTP_Callback : AWS.Response.Callback) return Handler;
    --  Returns an handler whose SOAP_Callback is the one below

    function SOAP_CB
      (SOAPAction : String;
       Payload    : Message.Payload.Object;
       Request    : AWS.Status.Data)
       return Response.Data;

 end Agg_Server_CB;

And following is an example on using such generated aggregate server
callback from a server's main::

    WS   : Server.HTTP;
    Conf : Config.Object;
    Disp : Agg_Server_CB.Handler;

 begin
    Config.Set.Server_Port (Conf, 0);

    Disp := Agg_Server_CB.Create (HTTP_CB'Access);

    AWS.Server.Start (WS, Disp, Conf);

.. _Using_ada2wsdl_and_wsdl2aws_together:

Using ada2wsdl and wsdl2aws together
====================================

Using both tools together is an effective way to build rapidely a `SOAP`
server. It can be said that doing so is quite trivial in fact. Let's
take the following spec::

 package Graphics is

    type Point is record
       X, Y : Float;
    end record;

    function Distance (P1, P2 : in Point) return Float;
    --  Returns the distance between points P1 and P2

 end Graphics;

We do not show the body here but we suppose it is implemented. To
build a server for this service it is as easy as::

 $ ada2wsdl -a http://localhost:8787 -o graphics.wsdl graphics.ads

The server will be available on localhost at port 8787::

 $ wsdl2aws -cb -main server -types graphics graphics.wsdl
 $ gnatmake server -largs ...

Options

*-cb*
  is to create the `SOAP` dispatcher callback routine,

*-main server*
  to generate the main server procedure in :file:`server.adb`,

*-types graphics*
  to use :file:`graphics.ads` to get references from user's spec (reference to
  `Graphics.Point` for example).