I don't understand what you mean by supporting a limited number of
types. Currently, mini-lang supports any type - thanks to the conversion
framework.
I like the idea of changing the from-field attribute to from. I would
like to see a from-script attribute added:
<set field="field4" from-script="groovy: parameters.inputField1 + 10"/><!-- Use
Groovy -->
Then we can remove script support from expressions, which will eliminate
ugly hacks like:
<set field="field4" value="${groovy: parameters.inputField1 + 10}"/>
-Adrian
On 3/6/2012 7:31 AM, Jacopo Cappellato wrote:
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
