SOAP vs REST

Presentation Transcript

Dec 7, 2007

Can you read this? If not, please sit closer. Thank you.

XML RPC (1998)

Request
<?xml version="1.0"?>
<methodCall>

<methodName>doSomeWork</methodName>
<params>

<param>

<value><int>40</int></value>

</param>
<param>

<value><double>-12.53</double></value>

</param>

</params>

</methodCall>
Response
<methodResponse>

<params>

<param>

<value>

<array>

<data>

<value><dateTime.iso8601>19980717T14:08:55</dateTime.iso8601></value>
<value><string>Something here</string></value>

</data>

</array>

</value>

</param>

</params>

</methodResponse>

Early SOAP (2000) “section 5 encoding”

<soap-env:envelope
soap-env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:soap-env="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:soap-enc="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:xsd="http://www.w3.org/1999/XMLSchema"
xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance">

<soap-env:header>

...

</soap-env:header>
<soap-env:body>

<m:doSomeWork xmlns:m="http://www.lab49.com/">

<foo xsi:type="xsd:int">40</foo>
<bar>-12.53</bar>

</m:doSomeWork>

</soap-env:body>

</soap-env:envelope>
<soap-env:Envelope

<soap-env:body>

<m:doSomeWorkResponse xmlns:m="http://www.lab49.com/">

<soap-enc:array soap-enc:arrayType="xsd:ur-type[2]">

<baz xsi:type="xsd:int">12345</baz>
<quux xsi:type="xsd:string">Something here</quux>

</soap-enc:array>

</m:doSomeWorkResponse>

</soap-env:Body>

</soap-env:Envelope>

SOAP fancy encoding rules

References:

<e:Book> <title>My Life and Work</title> <author href="#Person-1"/></e:Book>

<e:Person id="Person-1"> <name>Henry Ford</name> <address href="#Address-2"/></e:Person>

<e:Address id="Address-2"> <email>mailto:henryford@hotmail.com</email> <web>http://www.henryford.com</web></e:Address>

Sparse arrays:

<SOAP-ENC:Array SOAP-ENC:arrayType="xsd:string[,][4]"> <SOAP-ENC:Array href="#array-1" SOAP-ENC:position="[2]"/></SOAP-ENC:Array>

<SOAP-ENC:Array id="array-1" SOAP-ENC:arrayType="xsd:string[10,10]"> <item SOAP-ENC:position="[2,2]">Third row, third col</item> <item SOAP-ENC:position="[7,2]">Eighth row, third col</item></SOAP-ENC:Array>

Document/literal (2003): Forget all the fancy encoding rules

<soap-env:envelope

<soap-env:header>

...

</soap-env:header>
<soap-env:body>

… your XML Schema compliant document goes here …

</soap-env:body>

I want my, I want my RPC (rpc/literal)

<soap-env:envelope

<soap-env:header>

...

</soap-env:header>
<soap-env:body>

<m:doSomething xmlns:m=“http://lab49.com/”>

<foo>

… XML Schema compliant value…
…

</foo>
<bar>

…

</bar>

</m:doSomething>

</soap-env:body>

Namespace does not

have to be the same

as the parameter values

Argument elements don’t

even have a namespace

Lets you model procedure calls, but can’t validate SOAP body with an XML Schema

SOAP encoding convention line-up circa 2003

RPC/encoded (the original)
Document/literal (based on XML Schema, but doesn’t model RPC)
RPC/literal (adds RPC modeling, breaks XML Schema validation)

Can’t we model RPC without breaking Schema validation?

Wrapped document literal style (2005)

<soap-env:envelope

<soap-env:header>

...

</soap-env:header>
<soap-env:body>

<m:doSomething xmlns:m=“http://lab49.com/”>

<m:foo>

…

</m:foo>
<m:bar>

…

</m:bar>

</m:doSomething>

</soap-env:body>

Entire body complies with an XML Schema

containing element doSomething containing

a sequence of elements foo and bar

Handy summary

Web Service Definition Language (WSDL 1.1)

<definitions>

<types>

<schema>

<element name="doSomething">

<complexType>
<sequence>

<element name="foo" nillable="true" type="string" />
<element name="bar" nillable="true" type="double" />

</sequence>
</complexType>

</element>
<element name="doSomethingResponse">

...

</element>

</schema>

</types>
<message name="doSomethingRequest"> <part name="parameters" element="doSomething"></part> </message>
<message name="doSomethingResponse"> <part name="parameters" element="doSomethingResponse"></part> </message>
<portType name="myServices">