Re: Flow Layer Database API

[Christopher Oliver]

You know what? You're right. My description below was wrong. What I 
should have said is that I created a simple _JavaScript_ database API 
that can be used to implement business objects in JavaScript. This 
really has nothing to do with the "flow" layer per se, which is about 
controlling page flow. Instead, it aims to satisfy the niche that 
Sylvain identified and allow non-Java, non-O/R experts, a rapid 
development tool to also program business objects that can used by the 
Cocoon flow and presentation layers.

For example, if I were writing a "Petstore" application I could program 
both the business layer, and flow layer in JavaScript. For the business 
layer I might define a business object like this:

    function PetStore(poolId) {
        this.poolId = poolId;
    }
    PetStore.prototype.getProductListByCategory = function(key,
                                        skipResults, maxResults) {
        var conn = cocoon.getConnection(this.poolId);
        var result = conn.query("select * from PRODUCT where CATEGORY = 
" + key,
			    skipResults, maxResults);
        conn.close();
        return result;
    }

    // etc...

And for the flow layer I might write code like this:

    var petStore = new Petstore(...);

    function viewCategory() {
        var categoryId = cocoon.request.get("categoryId");
        var skipResults = 0;
        var maxResults = 10;
        do {
            var productList =
              petStore.getProductListByCategory(categoryId,
                                                skipResults,
                                                maxResults);
            skipResults += productList.rowCount;
            sendPageAndWait("view/Category.xml",
                        {productList: productList});
        } while (productList.limitedByMaxRows);
    }
    // etc ...

I believe if used properly this can still provide the correct SOC. What 
do you think?

Regards,

Chris

Gianugo Rabellino wrote:
Christopher Oliver wrote:

I've just committed [experimental] changes that provide a simple 
database API for the Cocoon flow layer modeled after JSTL 


[...]

Let me know what you think.

OK, first of all I must confess that I have little or no experience with 
the flow, so probably I should just shut up and let you guys proceed 
with your impressive work, eagerly waiting to have some time to catch up 
and join the party.

This said, I just wanted to share a couple of "belly thoughts", since 
the recent additions to the flow are ringing a bell in my head, and I 
start getting a bit puzzled. One of the first concerns we had when we 
started talking about flow was about people abusing it and how to stop 
them. The answer has always been that the flow would have played the 
role of "pure glue", providing, well, flow control and little more: in 
particular it was take for granted that the business objects would have 
been outside of the flow scope.