On 9/11/07, Jean-Sebastien Delfino <[EMAIL PROTECTED]> wrote:
>
> I checked in a version of the Store sample described in the Getting
> Started document a while ago.
>
> I'd like to describe a few thoughts on how to improve the sample with
> small changes to the sample itself and some improvements to the
> implementation.resource extension and how it integrates with Web
> 2.0-friendly bindings.
>
> The current Store sample looks like this:
>
> store.composite
> <composite xmlns="http://www.osoa.org/xmlns/sca/1.0";
> xmlns:t="http://tuscany.apache.org/xmlns/sca/1.0";
> xmlns:s="http://store";
> name="store">
>
> <component name="ufs">
> <t:implementation.resource location="ufservices"/>
> <service name="Resource">
> <t:binding.http/>
> </service>
> </component>
>
> <component name="Catalog">
> <implementation.java class="services.CatalogImpl"/>
> <property name="currencyCode">USD</property>
> <service name="Catalog">
> <t:binding.jsonrpc/>
> </service>
> <reference name="currencyConverter"
> target="CurrencyConverter"/>
> </component>
>
> <component name="ShoppingCart">
> <implementation.java class="services.ShoppingCartImpl"/>
> <service name="Collection">
> <t:binding.atom/>
> </service>
> </component>
>
> <component name="CurrencyConverter">
> <implementation.java class="services.CurrencyConverterImpl"/>
> </component>
>
> </composite>
>
> store.html
> <html>
> <head>
> <title>Store</title>
>
> <script type="text/javascript" src="binding-atom.js"></script>
> <script type="text/javascript" src="binding-jsonrpc.js"></script>
> <script language="JavaScript">
>
> //Reference
> catalog = (new JSONRpcClient("../Catalog/")).Catalog;
> //Reference
> shoppingCart = new AtomClient("../ShoppingCart/");
>
>
> We can see that the Catalog and ShoppingCart services offered to the
> Store client are properly modeled and configured with <binding.jsonrpc>
> and <binding.atom>. However the Composite does not describe any
> references on the UFS component. When you look at the composite you
> don't see that the client Javascript code in store.html actually
> references the Catalog and ShoppingCart services, and proxies to these
> services are constructed by hand in the client Javascript code.
>
> I think it would be better if we could write something like follows:
>
> store.composite
> <composite xmlns="http://www.osoa.org/xmlns/sca/1.0";
> xmlns:t="http://tuscany.apache.org/xmlns/sca/1.0";
> xmlns:s="http://store";
> name="store">
>
> <component name="ufs">
>
> <!-- Point directly to the HTML page -->
> <t:implementation.resource location="store.html"/>
> <service name="Resource">
> <t:binding.http/>
> </service>
>
> <!-- Describe references to the target services -->
> <reference name="catalog" target="Catalog">
> <t:binding.jsonrpc/>
> </reference>
> <reference name="shoppingCart" target="ShoppingCart">
> <t:binding.atom/>
> </reference>
>
> </component>
>
> <component name="Catalog">
> <implementation.java class="services.CatalogImpl"/>
> <property name="currencyCode">USD</property>
> <service name="Catalog">
> <t:binding.jsonrpc/>
> </service>
> <reference name="currencyConverter"
> target="CurrencyConverter"/>
> </component>
>
> <component name="ShoppingCart">
> <implementation.java class="services.ShoppingCartImpl"/>
> <service name="Collection">
> <t:binding.atom/>
> </service>
> </component>
>
> <component name="CurrencyConverter">
> <implementation.java class="services.CurrencyConverterImpl"/>
> </component>
>
> </composite>
>
>
> store.html
> <html>
> <head>
> <title>Store</title>
>
> <!-- include a single script, covering multiple bindings -->
> <script type="text/javascript" src="sca.js"></script>
> <script language="JavaScript">
>
> <!-- Simplified creation of the client proxies -->
> catalog = Reference("catalog");
> shoppingCart = Reference("shoppingCart");
>
> This introduces the following changes:
>
> In store.composite
>
> - The <implementation.resource> element directly points to store.html,
> so when you look at the .composite you know what HTML page is actually
> used.
>
> - The ufs component now declares correct references and wiring to other
> service components in the assembly.
>
> In store.html
>
> - A single sca.js script is generated for the client to include, very
> much like the generated scaDomain.js file, but covering multiple
> bindings, and customized for this particular UFS component and the
> references that were declared on it.
>
> - The client code is simpler, you can do catalog = Reference("catalog")
> or you could do something like catalog = references.catalog (where
> references.catalog would be initialized in sca.js), but I think I prefer
> the first form as it allows me to pick the name of the variable I'm
> going to use and Reference("catalog") also allows execution of some
> initialization code when the proxy is initialized.
>
> These changes should be possible with minimum effort but I think they
> will improve the sample a lot.
>
> Thoughts?
>
> --
> Jean-Sebastien
>
>
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>
> Hi Sebastien,
It looks like that, with this approach, we can hide the discontinuity
between the URL on which services are offered and the URL on which the HTML
page that uses them is provided. I like that.
A question from your comments though. Why do you imply that with approach
catalog = Reference("catalog") that no initialization in sca.js is
required? I'm missunderstanding you on this point.
Simon
