Voting on each item will not work because there are too many. We can
discuss things here and when there seems to be general agreement, I
will ask for a vote on the entire grammar. When that vote passes, I
will include the proposals in the grammar (move them out of the blue
boxes and into the normal text), and change the status from draft to
final.
-Adrian
Quoting Nicolas Malin <malin.nico...@librenberry.net>:
Thanks adrian for this works,
I will add my propositions.
After all proposition will include on wiki, how to you proceed to
approve each ? A vote on mailing list for each ?
Nicolas
Le 07/03/2012 19:18, Adrian Crum a écrit :
I created a Wiki page to help get things started:
https://cwiki.apache.org/confluence/display/OFBADMIN/Mini-language+Reference I put just enough information in it to work on the layout. I will continue working on it when I have time. Everyone with write access is welcome to work on it also. The information is based on the mini-language Java code - which is the ultimate authority. The schemas are inaccurate - they should be used only for looking up schema-supplied default
values.
The goal is to document the current mini-language grammar, and add
proposed changes. If a proposal is approved, then it can get a
green check mark. If a proposal is vetoed, then it can get a red X.
When everyone agrees on the grammar, the document will be updated,
and it will move out of the draft stage. Then the job will be to
work on the Java and XML code to make it match the grammar.
I put a couple of proposals in the page to help get things started.
Let me know what you think.
-Adrian
On 3/6/2012 9:42 AM, Adrian Crum wrote:
<set field="field4" from="parameters.inputField1 + 10"/> <!-- use
Minilang built-in and efficient support: not currently supported
but maybe something to consider in the future -->
The from attribute contains a UEL expression, so it is currently supported.
-Adrian
On 3/6/2012 9:33 AM, Jacopo Cappellato wrote:
On Mar 6, 2012, at 10:03 AM, Adrian Crum wrote:
Replacing FSE with Groovy is a bad idea. Adam and I optimized
FSE so that it is very lightweight and fast. I also optimized
the UEL integration so there is very little overhead in the
evaluation process. Switching everything to Groovy will slow
things down and increase memory usage. Also keep in mind that
Groovy creates a class for every script, so we will run out of
permgen space again.
Ok, makes perfect sense, thank you.
I think a wiser strategy would be to make mini-lang as feature
complete as possible, and include a from-script attribute for
any feature gaps. In other words, use from-script as a last
resort - because it is costly.
+1: by the way we could still use the "from" attribute for both:
<set field="field4" from="parameters.inputField1"/> <!-- use
Minilang built-in and efficient support -->
<set field="field4" from="parameters.inputField1 + 10"/> <!-- use
Minilang built-in and efficient support: not currently supported
but maybe something to consider in the future -->
<set field="field4" from="groovy: parameters.inputField1 + 10"/>
<!-- use Groovy (inefficient) -->
Jacopo
-Adrian
On 3/6/2012 8:53 AM, Jacopo Cappellato wrote:
On Mar 6, 2012, at 9:32 AM, Adrian Crum wrote:
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.
The conversion framework is fine; I was thinking that we could
implicitly (by default) treat in Minilang all the numbers as
BigDecimals, all the strings as GStrings/Expandable Strings;
where special conversions are required than the type can be
specified.
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 -->
and why not:
<set field="field4" from="parameters.inputField1"/><!-- Use
Groovy internally: refactor OFBiz custom code to delegate on
Groovy the evaluation of simple assignments; this could
potentially replace FlexibleStringExpander related code -->
<set field="field4" from="groovy: parameters.inputField1 +
10"/><!-- Use Groovy explicitly to evaluate the expression (use
the same "from" attribute instead of a separate "from-script")-->
<set field="field4" from="parameters.inputField1 + 10"/><!--
Use Groovy (by default, configurable) to evaluate the
expression-->
<set field="field4" from="beanshell: parameters.inputField1 +
10"/><!-- Use Beanshell to evaluate the expression-->
?
Then we can remove script support from expressions, which will
eliminate ugly hacks like:
<set field="field4" value="${groovy: parameters.inputField1 + 10}"/>
+1
Jacopo
-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
--
Nicolas MALIN
Consultant
Tél : 06.17.66.40.06
Site projet : http://www.neogia.org/
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