web_services.tex

\section{Web services}

\centeredFrame{Web services}
\centeredFrame{what exactly are web services?}
\centeredFrame{API for web applications}
\itemizedFrame{some examples:}{
\item weather
\item sport results
\item stock market
}
\centeredFrame{a bit of history}
\centeredFrame{Remote Procedure Call}

\centeredFrame{XML-RPC}
\centeredFrame{uses XML over HTTP}
\inputFrame{XML RPC sample request}{\tiny}{files/xml_rpc_request}
\inputFrame{XML RPC sample response}{\tiny}{files/xml_rpc_response}

\centeredFrame{this evolved into}

\centeredFrame{SOAP}
\centeredFrame{\alert{Simple} Object Access Protocol}
\itemizedFrame{this acronym was dropped with version 1.2 of the standard}{
\item it was confused with SOA
\item it’s not that simple after all
}
\centeredFrame{uses XML over HTTP}

\frame{
  \frametitle{SOAP sample request}
  \scriptsize \input {files/soap_request}
}
\frame{
  \frametitle{SOAP sample response}
  \scriptsize \input {files/soap_response}
}

\centeredFrame{services are defined using\\Web Services Description Language\\(WSDL)}
\frame{
  \frametitle{WSDL sample}
  \tiny \input {files/wsdl_begin}
}
\centeredFrame{... about 100 lines of XML later ...}
\frame{
  \frametitle{WSDL sample}
  \tiny \input {files/wsdl_end}
}
\itemizedFrame{}{
\item lets tools create client APIs
\item client developers see methods with parameters
}

\itemizedFrame{WS-* specifications}{
  \item WS-Addressing
  \item WS-Security
  \item WS-Trust
  \item WS-SecureConversation
  \item WS-ReliableMessaging
  \item WS-AtomicTransaction
  \item WS-Coordination
  \item WS-Policy
  \item WS-MetadataExchange
  \item ...
}
\imageFrame{images/WS-Standards-Poster.jpg}

\centeredFrame{service oriented design}
\itemizedFrame{}{
\item UserManager
  \begin{itemize}
  \item createUser(u:User)
  \item getUserDetails(id:ID)
  \end{itemize}
\item StatusManager
  \begin{itemize}
  \item submitStatus(u\_id:ID, s:Status)
  \item getStatus(u\_id:ID)
  \end{itemize}
}

\itemizedFrame{Cons of SOAP services:}{
  \item complex
  \item strong typing
  \item XML is not necessarily the best data format for the web
  \item non-uniform interface
  \item uses HTTP POST only
}
\centeredFrame{not everyone needs enterprisey and complex web services}
\centeredFrame{you don't have to use SOAP}
\centeredFrame{others don't}
\imageFrame{images/dirty-harry.jpg}
\itemizedFrame{}{
\item Amazon Web Services - provides both
  \begin{itemize}
  \item 20\% uses SOAP
  \item 80\% uses REST
  \end{itemize}
\item Google Search API - deprecated SOAP in favor of REST
\item Yahoo API - uses REST only
}