Re: Web service question... -- RPG400-L

To be even more clearer:

1.
A web service is any service accessed using the HTTP protocol, hence "web"
in the name.

3.
REST (representational state transfer) is an architecture to access and
manipulate "resources", were each resource can have specific
"representations" when transferred to a client (browser). For example i can
have a resource named "clients" and i can retrieve a list of customers with
URL ".../customers". The list of customers is transferred to the client
(browser) in XML format and this is a "representation" of this resource
(could be anything). I can also access the customer with number 1234 with
".../customer/1234 and i get a representation of this customer. To update a
customer with a new name, i POST to URL ".../customer/1234/update" with the
new name (e.g. in XML format) as the payload. In REST style, the HTTP (Web)
protocol is followed. Eg. the browser may use HTTP header "Accept:" to
indicate which "representations" (content-types) it accepts, and the
server's response includes HTTP header "Content-Type" to indicate which
representation is used. Also, the POST returns the location URL of the new
(or updated) resource. Also the "list of customers" should include the URL
locations of each "customer" resource, such that a browser could navigate
through all resource from one entry point (such as the list with customers,
then to a customer, then to it's orders, etc). Much like the Web works with
hyperlinks.
http://en.wikipedia.org/wiki/Representational_State_Transfer

On Tue, Jul 19, 2011 at 1:12 PM, Larry Ducie <larry_ducie@xxxxxxxxxxx>wrote:

Hi Robert,

I must confess to being ignorant of your needs here: You state "This link
is called repeatedly for all the items on a document." and I don't know what
you mean. I have lots of questions:

What is the document?
Where is the document?
How is the link called repeatedly?
What is making these repeated calls?
Why do you think a RPG program using HTTPAPI would be better than the
current implementation?
Is the document currently processed within a RPG program?

If the links are called through a browser via anchor tags or AJAX calls and
you are talking about moving those calls to the server - think carefully
before blocking the service in such a way.

(I'm here guessing because I don't know what you are doing, or what you
want to do)

But while I'm here... there seems to be some general confusion about web
services, which is not usually helped when such things as SOAP and REST are
bandied about. :-)

Lets make it clear:

1. A web service is a service provided by one machine that can be accessed
by another machine over a network
2. SOAP is a protocol, not a service
3. REST is an architecture, not a protocol, nor a service

REST is an architecture that allows the client to be "at rest" and only
access services when required. When changes occur that need to be propagated
to a remote service the client is in a brief state of flux and then goes
back to being "at rest". The use of the HTTP 1.1 protocol is a classic
implementation of a RESTful architecture - your browser is "at rest" until
you click something, or a time-based function fires up. It then performs a
required task (retrieve a resource, or post some information) and then goes
back to being "at rest".

I've probably not helped much, but I think I'd need more info to be really
useful. Unless your post was rhetorical.

Cheers

Larry Ducie
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