Creating Web Clients
A web client is software that accesses a web service. A web client provides a set of proxy methods, each of which corresponds to a method of the web service. A proxy method uses the same signature as the web service method to which it corresponds, and it invokes the web service method when asked to do so. This topic describes how to create and use web clients in InterSystems IRIS® data platform.
For information on logging SOAP calls to your InterSystems IRIS web clients, see InterSystems IRIS SOAP Log.
For an InterSystems IRIS web service, the automatically generated WSDL might not include information about the SOAP header elements:
If you add SOAP headers manually by setting the HeadersOut property, be sure to follow the instructions in Specifying Supported Header Elements, in Adding and Using Custom Header Elements. If you do, the WSDL contains all the applicable information. Otherwise, it does not, and you must save the WSDL to a file and edit it manually as needed.
If you add WS-Security header elements by setting the SecurityOut property (as described in Securing Web Services), the WSDL does not include all needed information. (This is because the WSDL is generated at compile time and the headers are added later, at runtime.) In this case, save the WSDL to a file and edit it manually as needed.
For many reasons, it is simpler and easier to add WS-Security elements by using WS-Policy, as described in Creating and Using Policies. With WS-Policy, the generated WSDL includes all needed information.
In other cases, the generated WSDL includes all needed information.
Note that the W3C specifications do not require a web service to provide a generated WSDL.
Overview of the SOAP Wizard
To create an InterSystems IRIS web client, you can use the SOAP Wizard in Studio or the corresponding class method provided by InterSystems IRIS. In either case, the input is a WSDL document. The tools generate a web client class and all needed supporting classes.
You can use the tool with nearly any WSDL document; see WSDL Support in InterSystems IRIS.
You can provide either the URL or the file path for the WSDL.
If the WSDL indicates support for both SOAP 1.1 and SOAP 1.2, then the SOAP Wizard generates two sets of classes, if needed.
Using the SOAP Wizard
If you have access to the WSDL that describes a given web service, you can use the SOAP Wizard in Studio to generate a web client for the service.
If you have enabled a proxy server, Studio uses it when communicating from templates such as the SOAP Wizard. For information about specifying a proxy server and port, see Using a Proxy Server.
To use the SOAP wizard:
In Studio, click Tools > Add-ins > SOAP Wizard.
On the first screen of the SOAP Wizard, specify the location of the WSDL and the SSL configuration required to access it:
Click URL or FILE to indicate the format of the WSDL.
Type the WSDL URL, or browse to the WSDL file.
If you specify a URL that requires SSL authentication (that is, if the URL begins with https), do the following:
Select an SSL configuration from the SSL Configuration drop-down list.
For information about creating and managing SSL/TLS configurations, see InterSystems TLS Guide.
The SSL Configuration field specifies only the SSL configuration that the wizard uses to access the WSDL.
Optionally, clear the When making an SSL connection check that the server identity in the server certificate matches the name of the system being connected to check box.
When the check box is selected, the wizard determines whether the certificate server name matches the DNS name used to connect to the server. If the names do not match, the connection is not permitted. This default behavior prevents man in the middle attacks and is described in RFC 2818Opens in a new tab, section 3.1. You can also see RFC 2595Opens in a new tab, section 2.4 for more information.
The wizard attempts to access and display the WSDL.
If the wizard is unsuccessful, an error appears. For possible causes, see Problems Consuming WSDLs.
If the wizard cannot access the WSDL URL after several attempts, you can save the WSDL as a file and browse to it instead.
If the wizard is successful, the Step 2 screen appears.
If the WSDL URL requires password authentication, specify your credentials:
Select the type of credentials to use:
For InterSystems IRIS credentials, select InterSystems IRIS user name and password.
For HTTP Basic authentication credentials, select HTTP authentication user name and password.
Fill in the Username and Password fields.
Click Try Again.
The wizard does not save your entries.
If the username and password are valid, the Step 2 screen appears.
For more information, see Using a Password-Protected WSDL URL.
On the Step 2 screen of the SOAP Wizard, specify how the wizard generates classes from the WSDL:
Configure the settings in the Options to control class generation and compilation area.
For descriptions of the settings, see SOAP Wizard Options to Control Class Generation and Compilation.
The Step 3 screen appears.
On the Step 3 screen of the SOAP Wizard, specify how the wizard packages the classes it generates from the WSDL:
Configure the settings at the top of the screen to determine how the wizard generates class packages from the XML namespaces in the WSDL.
For descriptions of the settings, see SOAP Wizard Options for XML Namespaces.
Optionally edit the class package names.
For information about the Package Name fields, see SOAP Wizard Rules for Class Package Names.
The wizard generates, compiles, and lists the classes. Then, the Step 4 screen appears.
If the name of an element in the schema begins with an underscore (_), then properties of the class generated for the element begin with a percent sign (%).
SOAP Wizard Options to Control Class Generation and Compilation
The Step 2 screen of the SOAP wizard includes the following options, which enable you to specify the types of classes that the wizard generates from the WSDL.
Create Client for Web Service
Indicates whether the wizard generates proxy classes that function as a client for the web service defined by the WSDL.
Create Web Service
Indicates whether the wizard generates classes that function as an InterSystems IRIS web service based on the WSDL.
Compile generated classes
Indicates whether the wizard compiles classes after generating them.
If you select Compile generated classes, you can control the behavior of the compiler by specifying flags in the Compile flags field. For more information, execute the following command:
Specifies the type of classes that the wizard generates from the WSDL. You can select one of the following options:
Add %OnDelete method to classes in order to cascade deletes
For persistent class types, indicates whether to implement the %OnDelete() callback method for each generated class definition. Do not use this option if you select Persistent using parent-child for relationships.
The generated %OnDelete() method deletes all persistent objects that are referenced by the class.
If you modify the generated classes, be sure to modify the corresponding %OnDelete() callback methods as needed.
Proxy Class Package
Package name for the web client and any generated classes.
The default package name is the service name.
If you specify an existing package name, the tool overwrites any existing class that has the same name as a newly generated class by default.
Create Business Operation
Indicates whether to generate a business operation and related request and response message classes, which you can use in a production.
For information about productions, see Introducing Interoperability Productions and Creating Web Services and Web Clients in Productions.
If you select Create Business Operation, you must specify the following values:
Business Operation Package — Package name for the business operation class.
Request Package — Package name for the request message class.
Response Package — Package name for the response message class.
SOAP Wizard Options for XML Namespaces
The Step 3 screen of the SOAP wizard includes the following options, which enable you to configure the class packages generated from the WSDL:
Add NAMESPACE class parameter
Indicates whether the generated type class will include the NAMESPACE class parameter set equal to the namespace of the web service.
If the WSDL explicitly indicates the namespace to which a given type belongs, Add NAMESPACE Class Parameter is selected and grayed out. In this case, the generated type class includes the NAMESPACE class parameter set equal to that namespace.
If the WSDL does not indicate the namespace for a given type, you can select or clear Add NAMESPACE Class Parameter.
Use unwrapped message format for document style web methods
Indicates whether to use an unwrapped message format for the methods in the generated web client. This option affects only methods that have SoapBindingStyle equal to "document".
If either of the following statements are true of the WSDL, select this check box:
Alternatively, the wizard fails and displays an error message such as the following:
ERROR #6425: Element 'wsdl:binding:operation:msg:input' - message 'AddSoapOut'
Message Style must be used for document style message with 2 or more parts.
For more information, see Details of the Generated Classes and Using InterSystems IRIS Web Client Classes.
Do not create array properties
Indicates whether the wizard generates array properties.
If you select this option, the wizard does not generate array properties but instead generates another form. For more information, see Creation of Array Properties.
Generate XMLNIL property parameter for nillable elements
Indicates whether the wizard specifies the XMLNIL property parameter for applicable properties in the generated classes.
This option applies to each property that corresponds to an XML element that is specified with nillable="true". If you select this option, the wizard adds XMLNIL=1 to the property definition. Otherwise, it does not add this parameter.
For details on this property parameter, see Handling Empty Strings and Null Values.
Generate XMLNILNOOBJECT property parameter for nillable elements
Indicates whether the wizard specifies the XMLNILNOOBJECT property parameter for applicable properties in the generated classes.
This option applies to each property that corresponds to an XML element that is specified with nillable="true". If you select this option, the wizard adds XMLNILNOOBJECT=1 to the property definition. Otherwise, it does not add this parameter. For details on this parameter, see Handling Empty Strings and Null Values.
Set XMLSEQUENCE parameter to 0
Indicates whether the wizard sets the XMLSEQUENCE class parameter in the generated classes to 0.
By default, the wizard sets this parameter to 1 in the generated classes, which ensures that the classes respect the order of elements as given in the schema in the WSDL. This value is useful when the schema has multiple elements of the same name within a given parent. For details, see Handling a Document with Multiple Tags with the Same Name.
Generate XMLIGNORENULL parameter set to 1
Indicates whether the wizard specifies the XMLIGNORENULL class parameter in the generated classes.
If you select this option, the wizard adds XMLIGNORENULL=1 to the class definitions, including the generated web client (or web service). Otherwise, it does not add this parameter.
For details on this class parameter, see Handling Empty Strings and Null Values.
Specify SECURITYIN class parameter
Specifies the value of the SECURITYIN class parameter in the generated client class.
If you are using Web-Services security, use REQUIRE or ALLOW, depending on whether you want the client to require the elements or simply validate them. Otherwise, IGNORE or IGNOREALL is generally suitable. For details, see Validating WS-Security Headers.
The SECURITYIN parameter is ignored if there is a security policy in an associated (and compiled) configuration class. See Securing Web Services.
SOAP Wizard Rules for Class Package Names
The SOAP Wizard applies the following rules for class package names:
The packages specified in the Web Client Package and Web Service Package fields contain the main generated web client or web service class. These values are initialized by your entry in the previous page of the wizard.
If the wizard generates a policy class as well (because the WSDL contains WS-Policy information), that class is in the same package by default. To specify a different package, specify a value for Configuration Sub-Package.
By default, the class name is the web client or service name, with Config appended to it. If you specify a value for Configuration Sub-Package, then this generated class has the same name as the web client or service (but is in the given subpackage instead).
For information on WS-Policy, see Securing Web Services.
For any supporting classes that are generated, the wizard detects all the namespaces used in the WSDL. By default, it organizes the generated classes into packages, with one package for each namespace.
Optionally edit these package names.
Not all namespaces necessarily correspond to generated classes. For example, the WSDL used in this example uses the namespaces https://schemas.xmlsoap.org/wsdl, https://schemas.xmlsoap.org/wsdl/mime, and https://schemas.xmlsoap.org/wsdl/soap. No generated classes are in these namespaces in this case, and the corresponding packages are not generated.
Generating the Client Classes Programmatically
You can instead generate the client classes programmatically by using the %SOAP.WSDL.ReaderOpens in a new tab class.
The resulting generated classes and their organization may not be the same as if you used the SOAP wizard, which provides greater control over the packages for the generated classes.
To generate the client classes programmatically:
Create an instance of %SOAP.WSDL.ReaderOpens in a new tab.
Optionally set properties to control the behavior of your instance. For details, see the class documentation for %SOAP.WSDL.ReaderOpens in a new tab.
Note that if the WSDL is at a location that uses SSL, %SOAP.WSDL.ReaderOpens in a new tab will (by default) checks whether the certificate server name matches the DNS name used to connect to the server. If these names do not match, the connection is not permitted. This default behavior prevents man in the middle attacks and is described in RFC 2818Opens in a new tab, section 3.1; also see RFC 2595Opens in a new tab, section 2.4.
To disable this check, set the SSLCheckServerIdentity property of the instance equal to 0.
If you need the ability to control the HTTP request in a way that is not directly supported by %SOAP.WSDL.ReaderOpens in a new tab, do this:
Create an instance of %Net.HttpRequestOpens in a new tab and set its properties as needed.
For your instance of %SOAP.WSDL.ReaderOpens in a new tab, set the HttpRequest property equal to the instance of %Net.HttpRequestOpens in a new tab that you just created.
For example, you might do this if the server requires authentication. See Providing Login Credentials in Sending HTTP Requests.
Invoke the Process() method of your instance:
method Process(pLocationURL As %String, pPackage As %String = "") as %Status
pLocationURL must be the URL of the WSDL of the web service or the name of the WSDL file (including its complete path). Depending on the configuration of the web service, it may be necessary to append a string that provides a suitable username and password; see the examples.
pPackage is the name of the package in which to place the generated classes. If you do not specify a package, InterSystems IRIS uses the service name as the package name.
If this package is the same as an existing package, by default the tool overwrites any existing classes that have the same name. To prevent the tool from overwriting a class definition, add the following to that class definition:
Parameter XMLKEEPCLASS = 1;
The following shows an example Terminal session:
Compilation started on 11/09/2009 12:53:52 with qualifiers 'dk'
Compiling class AddComplex.ns2.ComplexNumber
Compiling routine AddComplex.ns2.ComplexNumber.1
Compilation finished successfully in 0.170s.
Compilation started on 11/09/2009 12:53:52 with qualifiers 'dk'
Compiling class AddComplex.AddComplexSoap
Compiling routine AddComplex.AddComplexSoap.1
Compiling class AddComplex.AddComplexSoap.Add
Compiling routine AddComplex.AddComplexSoap.Add.1
Compilation finished successfully in 0.363s.
The WSDL URL is part of a web application, which might be protected by password authentication. For details on using the WSDL in this case, to generate InterSystems IRIS web clients or third-party web clients, see Using a Password-Protected WSDL URL.
In all cases, it is also possible to retrieve the WSDL from a browser after supplying the required username and password, save it as a file, and use the file instead.
Modifying the Generated Client Classes
After you generate an InterSystems IRIS web client class, you do not usually edit the class. Instead you write code that creates an instance of the web client and that provides provide client-side error handling. This section documents the notable exceptions where you do modify the generated client class.
Also see Additional Notes on Web Methods in the Generated Class and Fine-Tuning a Web Client in InterSystems IRIS.
Do not create a subclass of the generated web client class. The compiler will not generate the supporting classes that it would need in order to run properly, and your subclass would not be usable.
Adjusting the Generated Classes for Extremely Long Strings
In rare cases, you might need to edit the generated client class to accommodate extremely long strings or binary values — values whose lengths exceed the string length limit.
When the SOAP Wizard reads a WSDL, it assumes that any string-type input or output can be represented in InterSystems IRIS as %StringOpens in a new tab, which is not always true. In rare cases, a string might exceed the string length limit. Similarly, the wizard assumes that any input or output with XML type base64Binary can be represented in InterSystems IRIS as %xsd.base64BinaryOpens in a new tab), which is not always true, due to the same string length limitation. In neither case does the WSDL contain any information to indicate that this input or output could exceed the string length limit.
When your web client encounters a string or a binary value that is too long, it throws one of the following errors:
A <MAXSTRING> error
A datatype validation error:
ERROR #6232: Datatype validation failed for tag your_method_name ...
(This error, of course, can also be caused by a datatype mismatch.)
The problem, however, is easy to correct: adjust the method signature in your generated web client class (specifically the class that inherits from %SOAP.WebClientOpens in a new tab) to use an appropriate stream class:
For example, consider a web service (MyGiantStringService) that has one method (WriteIt), which takes no arguments and returns a very long string. If you use the SOAP Wizard to generate the web client class, the web client class originally looks something like this:
Class GetGiantString.MyServiceSoap Extends %SOAP.WebClient
Method WriteIt() As %String
In this case, there is only one adjustment to make. Change the return type of WriteIt as follows:
Method WriteIt() As %GlobalCharacterStream
When you compile this class, the system automatically regenerates the associated classes as needed.
You may also need to adjust property types within any generated type classes. For example, suppose the web service uses an element called <Container>, which includes an element <ContainerPart> of type string. When you generate the InterSystems IRIS web client classes, the system creates a Container class with a ContainerPart property of type %StringOpens in a new tab. If the web service sends a string longer than the string length limit in the <ContainerPart> element, your web client throws an error. To avoid this error, change the type of the ContainerPart property to %GlobalCharacterStreamOpens in a new tab.
If the WSDL does not specify the location of the web service, the SOAP Wizard does not specify the LOCATION parameter of the web client. This is a rare scenario. In this scenario, edit the web client class to include the LOCATION parameter. For example:
Parameter LOCATION = "https://devsys/csp/mysamples/GSOP.AddComplexWS.cls";
Or specify the Location property of your web client instance as shown later in this topic.
You might need to adjust other parameters of the web client class to make other changes. See Fine-Tuning a Web Client in InterSystems IRIS for details.
Using the Generated Web Client Classes
As noted in the previous section, after you generate an InterSystems IRIS web client class, you do not usually edit the generated class. Instead you write code that creates an instance of that web client and that provides provide client-side error handling. In this code, do the following:
Create an instance of the web client class.
Set its properties. Here you can control items such as the following:
Endpoint of the web client (the URL of the web service it uses). To control this, set the Location property, which overrides the LOCATION parameter of the web client class.
Settings that designate a proxy server.
Settings that control HTTP Basic authentication.
See the next section as well as Fine-Tuning a Web Client in InterSystems IRIS.
Invoke the methods of the web client as needed.
Perform client-side error handling. See SOAP Fault Handling.
Optionally examine the HTTP response received by the web client, as described later in this topic.
The following shows a simple example, from a session in the Terminal:
Example 1: Using the Client That Uses Wrapped Messages
In this example, we create a wrapper class for a web client that uses wrapped messages. To use the example GSOAPClient.AddComplex.AddComplexSoap shown previously, we could create a class like the following:
Class GSOAPClient.AddComplex.UseClient Extends %RegisteredObject
ClassMethod Add(arg1 As ComplexNumber, arg2 As ComplexNumber) As ComplexNumber
//uncomment the following to enable tracing
The client application would invoke this method in order to execute the web method.
Example 2: Using the Client That Uses Unwrapped Messages
In this example, we create a wrapper class for a web client that uses unwrapped messages. To use the example GSOAPClient.AddComplex.AddComplexSoap shown previously, we could create a class like the following:
Class GSOAPClient.AddComplexUnwrapped.UseClient Extends %RegisteredObject
ClassMethod Add(arg1 As GSOAPClient.AddComplexUnwrapped.s0.ComplexNumber,
arg2 As GSOAPClient.AddComplexUnwrapped.s0.ComplexNumber)
//create the Add message
Set addmessage.a = arg1
Set addmessage.b = arg2
//send the Add message to client and get response
//get the result from the response message
The method has the signature that would typically be expected; that is, it accepts two complex numbers and returns a complex number. The method creates the message that the web client expects. The elements of this message are the two complex numbers.
As you can see, when the web client uses unwrapped messages, it is necessary to write slightly more code to convert arguments in a user-friendly form into the message used by the web client.
Adjusting Properties of a Web Client Instance
When you use an instance of your web client classes, you can specify properties of that instance to control its behavior. This section discusses the properties that are most commonly set, as well as their default values.
Changing the Endpoint for the Web Client
The SOAP Wizard automatically sets the endpoint for the web client by setting the LOCATION parameter of the web client. By default, it sets this parameter equal to the URL of the web service with which it communicates.
To override this, set the Location property of your web client instance. If Location is null, then the LOCATION parameter is used.
A common usage is to set the Location property to use a different port, in order to enable tracing. For example, suppose that in the generated web client class, the endpoint is defined as follows:
Parameter LOCATION = "https://devsys/csp/mysamples/GSOP.AddComplexWS.cls";
When you use this client, you can include the following line:
If the WSDL does not specify the location of the web service, the SOAP Wizard does not specify the LOCATION parameter of the web client. This is a rare scenario. In this scenario, either edit the web client class to include the LOCATION parameter or specify the Location property of your web client instance as shown here.
Configuring the Client to Use SSL
If the endpoint for a web client has HTTPS protocol, the web client must be configured to use SSL. Specifically:
If you have not already done so, use the Management Portal to create an SSL/TLS configuration that contains the details of the needed SSL connection. For information, see About Configurations in the TLS Guide.
Set the SSLConfiguration property of the web client equal to that SSL/TLS configuration name.
Note that if the client is connecting via a proxy server, you must also set the HttpProxySSLConnect property equal to 1 in the web client. For information on configuring an InterSystems IRIS web client to use a proxy server, see Fine-Tuning the Web Client.
Specifying the SOAP Version
The SOAP Wizard automatically specifies the SOAP version to use in request messages, based on the SOAP version in the WSDL of the web service. Specifically it sets the SOAPVERSION parameter.
To override this, set the SoapVersion property of your web client instance. Use one of the following values:
"" — The client sends SOAP 1.1 messages.
"1.1" — The client sends SOAP 1.1 messages.
"1.2" — The client sends SOAP 1.2 messages.
If SoapVersion is null, then the SOAPVERSION parameter is used.
Using the HTTP Response
By default, when you invoke a web client method, you do so via HTTP. The HTTP response is then available as the HttpResponse property of the web client instance. This property is an instance of %Net.HttpResponseOpens in a new tab, which in turn has properties like the following:
Headers contains the headers of the HTTP response.
Data is an InterSystems IRIS multidimensional array that contains any data in the HTTP response.
StatusCode, StatusLine, and ReasonPhrase provide status information.
For details, see Using Internet Utilities or see the class documentation for %Net.HttpResponseOpens in a new tab.