I am a big fan of Minilang too.
The "evolution" strategy that I would like to see implemented for Minilang is
actually the same one I would liketo see applied to OFBiz framework in general:
review the current usage of the tool, fix existing usage for consistency
(upgrade old code to use newer mechanisms offered by the tool), get rid of
unused or old mechanisms in the attempt to slim down the size of the framework
code, unify/simplify mechanisms based on lesson learned; all of this could be
useful even to prepare the future migration to a different tool (e.g. Groovy).
I know that it is very vague and doesn't add much to this thread but I like the
approach suggested by Adrian.
In my opinion, a good way to define a new version of the "set" operation could
be that of analyzing how we are currently using the operation in OFBiz: as a
starting point we could start by searching all occurrences of "<set " string in
OFBiz, then review them and see different patterns; discuss and define the few
ones that we like more, convert all code to use them consistently, then (or in
the same phase) define the new element to better implement the patterns that we
like.
And now I am switching to the "brainstorming" mode :-)
Kind regards,
Jacopo
========================
<brainstorming>
I would like to have a "set" operation that implements some of the ideas of the
"configure by exception" concept.
As regards the type supported, but pending the review of existing usage, we may
consider to only support these:
* Object
* List
* Map
* BigDecimal/BigInteger (all numbers in Minilang should be treated as
BigDecimal; no support for Integer, Float etc...)
* String (expander i.e. the equivalent of GString in Groovy)
* a date object
Then we could get rid of the "from-field" attribute and replace it with a
"from" attribute that can take as input a single field (as it is now) or an
expression; some examples (all the following are evaluated using Groovy except
where a different language is specified i.e. default scripting language):
<set field="field1" from="parameters.inputField1"/> // field1 will have the
same type of inputField1
<set field="field2" from="parameters.inputField1 + parameters.inputField2"/> //
if inputField1 and inputField2 are numbers then field2 will be the BigDecimal
sum of the two
<set field="field3" from="parameters.inputField1 * 10"/>
<set field="field4" from="script:bsh parameters.inputField1 + 10"/> // use
Beanshell
<set field="field5" from="parameters.inputField1" type="BigDecimal"/> // if
inputField1 is a string representation of a number we can convert with the
explicit definition of the type
For the constant values (I am not sure if it is a good idea, but for now I will
throw it out):
<set field="stringField" value="This is a string"/>
<set field="stringField" value="This is a string with a ${variable}"/>
// the following two are equivalent
<set field="bigDecimalField" value="100"/> // the system attempt to parse "100"
as a number first (BigDecimal) and then as a string
<set field="bigDecimalField" value="100" type="BigDecimal"/>
<set field="stringField" value="100" type="String"/> // treat the field as a
string
</brainstorming>
On Mar 5, 2012, at 9:07 PM, Adrian Crum wrote:
> I am not one of those people. I use mini-lang almost exclusively.
>
> -Adrian
>
> On 3/5/2012 7:46 PM, Anil Patel wrote:
>> Adrian,
>> Thanks for starting this thread.
>>
>> While we all love mini-lang, I am wondering if we should really ask
>> ourselves if we really want to overhaul mini-lang or should we consider
>> alternates. From what I know, Not many people like to build application
>> using mini lang. Many end up using Java or Groovy.
>>
>> Thanks and Regards
>> Anil Patel
>> HotWax Media Inc
>>
>> On Mar 5, 2012, at 9:47 AM, Adrian Crum wrote:
>>
>>> Mini-language has evolved a lot over the years. Most of the development has
>>> occurred on an as-needed basis, so there is no clear design or
>>> implementation - things just get tacked on over time.
>>>
>>> A recent discussion has opened up the possibility to rework the
>>> mini-language<set> element. From my perspective, that task is long overdue.
>>>
>>> Also, the schemas are out of date, and they are unnecessarily complicated.
>>> So, those need a thorough going over.
>>>
>>> While we are at it, why don't we create a draft design document based on
>>> the current implementation, and then use it to look for other ways
>>> mini-language can be improved? We can all offer suggestions and comments,
>>> agree on a final design, finalize the draft, and then implement it in code.
>>> The design document then becomes the developer's reference.
>>>
>>> What do you think?
>>>
>>> -Adrian
>>>
