Web Interface and XML binding

[Jan van de Sandt]

Hello,

On Tue, Feb 9, 2010 at 12:23 PM, Norbert Hartl <norbert at hartl.name> wrote:

> Hi Jan,
>
> that looks great. I really would like to have a look at the code. May I
> have a few questions upfront:
>
> Ok, I will upload the code this evening.


> - I assume MAXMLTestPerson is the class name of the instance you are
> serializing. I would avoid exposing an implementation detail to the outside
> world. Do you use that information on parse time? I would expect that you
> know how to parse the top level object (by service context etc.). Regarding
> references the detail about what to parse is in MAReferenceDescription you
> are using for e.g. the address. If this is all right you could go with
> <Person> and <Address>. This would make it possible to parse the XML with a
> subclass of e.g. MAXMLTestPerson
>
> Yes MAXMLTestPerson is the class name. This was the easiest way to
serialize instances of classes that have the same Magritte description. This
behaviour is implemented in MAXMLWriter, a subclass of MAWriter. It can be
easily customized by creating your own subclass of this visitor.



> - You inlined the address instance into the person. Is this exchangable?
> I'm not sure I'll go for REST but if yes then I would like to do it by
> reference. Let's say <adress id="http://my.service.srv/address/12345"> ...
>
> The current implementation inlines the first occurrence of an object and
adds an id attribute. If an object occurs multiple times than a reference to
the id is inlined. For example:

Smalltalk:

personWithFriendsCycle

    | bill john carl |

    bill := MAXMLTestPerson new
        name: 'Bill';
        yourself.
    john := MAXMLTestPerson new
        name: 'John';
        yourself.
    carl := MAXMLTestPerson new
        name: 'Carl';
        friends: (OrderedCollection with: bill with: john);
        yourself.

    bill friends: (OrderedCollection with: john with: carl).
    john friends: (OrderedCollection with: bill with: carl).

    ^carl

XML:

<MAXMLTestPerson id="1">
    <name>Carl</name>
    <friends>
        <OrderedCollection>
            <MAXMLTestPerson id="2">
                <name>Bill</name>
                <friends>
                    <OrderedCollection>
                        <MAXMLTestPerson id="3">
                            <name>John</name>
                            <friends>
                                <OrderedCollection>
                                    <MAXMLTestPerson ref="2"/>
                                    <MAXMLTestPerson ref="1"/>
                                </OrderedCollection>
                            </friends>
                        </MAXMLTestPerson>
                        <MAXMLTestPerson ref="1"/>
                    </OrderedCollection>
                </friends>
            </MAXMLTestPerson>
            <MAXMLTestPerson ref="3"/>
        </OrderedCollection>
    </friends>
</MAXMLTestPerson>



> - What do you do with the date field in birthday? Is this a fixed format or
> do you specify this over magritte?
>
> This is also implemented using the MAXMLWriter visitor and can be easily
customized per description class.

Jan.


>
>
> On 09.02.2010, at 11:59, Jan van de Sandt wrote:
>
> Hello Norbert,
>
> I have developed some code to serialize object to XML and visa versa using
> their Magritte descriptions. It is not completely finished yet but for
> standard scenario's it works fine.
>
> Here an example where an instance of MAXMLTestPerson is serialized to XML.
>
>    <MAXMLTestPerson>
>         <name>Bill Gates</name>
>         <address>
>             <MAXMLTestAddress>
>                 <city>Amsterdam</city>
>                 <street>Mainstreet</street>
>             </MAXMLTestAddress>
>         </address>
>         <birthDate>1966-10-20</birthDate>
>     </MAXMLTestPerson>
>
> It can be de-serialized using MAXMLParser:
>
>     MAXMLParser parse: self personWithAddressXML readStream.
>
> The serialization process can be customized. I still have to add proper
> error handling. My intention was to add it to the Magritte add-ons
> repository when the error handling was fully working. If you want I can add
> it sooner so you can have a look.
>
> Jan.
>
>
>
>
> On Tue, Feb 9, 2010 at 11:22 AM, Norbert Hartl <norbert at hartl.name> wrote:
>
>> Hi,
>>
>> at the moment I'm thinking about a new project. The project will need a
>> Web API to communicate with an iphone. To me it is quite obvious to
>> implement the API part as a request handler. But when it comes to generation
>> of e.g. XML I'm not sure what is the best way to do.
>>
>> Sure, the seaside way to do it is to create my own canvas and every object
>> needs to draw itself onto the canvas. But then I have magritte and a lot
>> could be done automatically. Using xpath in the descriptions I could use
>> Pastell to deserialize objects. To produce the output there could be a
>> similar way. This would be some kind of XML binding then.
>>
>> I wanted to ask if there is anything already available that could help me
>> on my way or if there dedicated ideas how to solve this in seaside.
>>
>> thanks  in advance,
>>
>> Norbert
>>
>>
>>
>> _______________________________________________
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>
>
>
> --
> Jan van de Sandt
> gsm: +31 (0)6 3039 5998
> _______________________________________________
> Magritte, Pier and Related Tools ...
> https://www.iam.unibe.ch/mailman/listinfo/smallwiki
>
>
>
> _______________________________________________
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>



-- 
Jan van de Sandt
gsm: +31 (0)6 3039 5998
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