JIT or custom pipelines without field definitions

rbuser

Hi

I'm currently evaluating rbuilder for a project involving a MDA framework
(Bold for Delphi www.boldsoft.com).

As the Bold framework provides an object model, and object traversals with
OCL expressions, I don't want to use field definitions.

I did some tests using the JIT Pipeline, but it wouldn't work without
defining fields. I tried it, specifying fieldnames in data controls. The JIT
Event for GetFieldValue was correctly triggered with my expression from the
control, but the data wasn't displayed until I defined the fields on the JIT
Pipeline.

How deep are field definitions integrated in the reporting code ? Would it
be possible to derive a custom Pipeline that doesn't need field definitions
?
Can master/detail bands be realized without field definitions, just by
specifying a master pipeline and a link expression ?

thanks for answers

Samuel Iseli

digitalmetaphors

You need field definitions in order to create a report with data fields.
This is the only way that the report engine will know how to traverse
records. If you have no fields, then you have no report data to generate.
However, you can disconnect the report from the datapipeline. Set
Report.Autostop to false. Then the detail band will generate forever. You
could use this approach if you have no data but want to print detail bands
for some number of iterations. You can set Autostop to true and the report
will stop generating detail bands.


Cheers,

Jim Bennett
Digital Metaphors

rbuser

Hi Jim

I see that a pipeline is needed for report data traversal, but why can't the
report engine just pass 'fieldnames' it encounters in datafields on to the
pipeline and print the result it gets back ?

thanks

Samuel Iseli
vertec ltd

digitalmetaphors

The report data aware controls require a field to be connceted to on the JIT
pipeline. Certainly, you can define zero fields at design time and create
fields on your JIT pipeline at runtime. This is probalby the way to go on
this one.


Cheers,

Jim Bennett
Digital Metaphors

rbuser

"Samuel Iseli" wrote in news:3d69fd98@dm500.:


Does the Bold framework provide a way to get an object's properties at run
time? If so you can create a custom pipeline that uses it to create the
necessary fields.

We have an ObjectSource that provides this information for our object
hierachy as well as methods to get and set property values. ObjectSource
users have no knowledge of the underlying object.

I wrote an ObjectSource aware custom pipeline with an ObjectSource
property. When this property is set, it uses the ObjectSource's property
list to create fields. I remember that there was some non-obvious but
easy things required for the fields to be created property.

Joanne