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Posted to dev@freemarker.apache.org by Daniel Dekany <da...@gmail.com> on 2020/07/03 21:25:43 UTC
Re: Help needed for FREEMARKER-148 ...
How do you intend to have map semantics and still expose helper methods?
I'm not asking how would you implement that, but how would it look in the
templates?
On Tue, Jun 30, 2020 at 9:28 PM Siegfried Goeschl <
siegfried.goeschl@gmail.com> wrote:
> Hi folks,
>
> Following up a discussion with Daniel I would like to make "DataSources"
> (contains the user-supplied data sources) a bit more FTL friendly
>
> Had a quick look at it but I'm a bit lost
> I created a DataSourcesAdapter which extends TemplateSequenceModel &
> TemplateHashModel
> DataSources has a few additional finder methods which I can't invoke when
> exposing the DataSourcesAdapter
> So the question is what interfaces needs to be implemented to support
> sequence semantics
> hash map semantics
> arbitrary helper methods
> in a single adapter
>
> Thanks in advance,
>
> Siegfried Goeschl
>
>
--
Best regards,
Daniel Dekany
Re: Help needed for FREEMARKER-148 ...
Posted by Daniel Dekany <da...@gmail.com>.
On Sun, Jul 5, 2020 at 4:19 PM Siegfried Goeschl <
siegfried.goeschl@gmail.com> wrote:
> See my comments inline ...
>
> > On 05.07.2020, at 15:25, Daniel Dekany <da...@gmail.com> wrote:
> >
> > See my comments inline...
> >
> > On Sun, Jul 5, 2020 at 2:49 PM Siegfried Goeschl <
> > siegfried.goeschl@gmail.com <ma...@gmail.com>> wrote:
> >
> >> Hi Daniel,
> >>
> >> Please see my comments below
> >>
> >> Thanks in advance,
> >>
> >> Siegfried Goeschl
> >>
> >>
> >>
> >>> On 05.07.2020, at 13:42, Daniel Dekany <da...@gmail.com>
> wrote:
> >>>
> >>> The reason I was asking is that if all functionality goes in
> >> DataSourcers,
> >>> the methods will shadow data source names. Like if you have a data
> source
> >>> named "empty", then DataSources.empty will not return that, instead it
> >> will
> >>> call isEmpty(). That also means that adding new methods to DataSource
> is
> >>> not backward compatible. So probably we will need a separate
> DataSources,
> >>> and DataSourceTool or something. (It's also possible to reverse
> >> priorities,
> >>> but that's even less manageable for the user.)
> >>
> >> Thanks, I was not aware of that - let me recap my understanding
> >>
> >> If I have a data source "empty", e.g. "empty=somepath/some.csv"
> >>
> >> * DataSources.empty would call DataSources.isEmpty()
> >> * DataSources["empty"] would fetch the data source "empty"
> >>
> >
> > Yeah, so thing is, in FreeMarker, foo.bar and foo["bar"] are exactly the
> > same. Furthermore, foo.bar() is just foo.bar, and then () operator is
> > applied on it's value (which is a method as a first class value).
> >
> >
> >> * DataSources.get("empty") would fetch the data source "empty" since it
> >> calls DataSources.get(String)
> >>
> >
> > Yes.
> >
> >
> >> Some thoughts along the line
> >>
> >> * The names of a list of data sources are not enforced to be unique so
> the
> >> map functionality is slightly broken
> >>
> >
> > Why not? That was also a quite important problem. I guess I even listed
> it
> > in the recent mail... or not. So these names and groups, should be
> > consolidated too.
>
> Harvesting directory trees and consolidating the files into a single
> output - here I can't guarantee that the names are unique
>
Why don't we just enforce the names to be unique? Then the map function
won't be kind of broken either. But most importantly, user
templates won't be, because when you care about the data source name, you
(I mean the user) probably wan it to be unique, right? Like here, the
intent is most certainly that "DataSources.accessLog" is not ambiguous in
templates:
-s accessLog=foo/access.log
Yes, we also generate some "name" automatically, by taking part of an URL
(like the file name part). Well, if someone is bothered by that (I would
be), they can assign a name explicitly. But when files are collected by
scanning a directory, then you are out of control, so at least then they
shouldn't get a name by default. (The collected data sources still can have
properties like file name, if someone cares, but then it's obvious that
they aren't necessarily unique.)
>
> >
> >> * Tools for me are stateless and can be potentially shared so I can not
> >> put the data sources for the current transformation in there
> >>
> >
> > I guess, technically speaking, you can. You are in the context of a
> > freemarker-generator run (or whatever the term for that is... session?).
> > Where's the ambiguity, or similar issue, if any?
>
> Still want to make the code embeddable so in my mental model the tools are
> reusable and do not contain "session-specific" data
>
Some possible solutions:
- Let's pass DataSources as an argument to the tool methods then.
- Or, let's not call that thing a tool then, so it can know about the
session.
- Or DataSources should contain a collection of objects that has a
matchedGlob method (among others), and then you can issue
DataSources?filter(ds -> ds.matchesGlob('*.foo')). A bit verbose though.
And bit indecisive maybe, as I guess the idea is that some stuff is just
data, and methods that are not mere data access are in "tools".
>
> > [snip]
> >
> > --
> > Best regards,
> > Daniel Dekany
>
>
--
Best regards,
Daniel Dekany
Re: Help needed for FREEMARKER-148 ...
Posted by Siegfried Goeschl <si...@gmail.com>.
See my comments inline ...
> On 05.07.2020, at 15:25, Daniel Dekany <da...@gmail.com> wrote:
>
> See my comments inline...
>
> On Sun, Jul 5, 2020 at 2:49 PM Siegfried Goeschl <
> siegfried.goeschl@gmail.com <ma...@gmail.com>> wrote:
>
>> Hi Daniel,
>>
>> Please see my comments below
>>
>> Thanks in advance,
>>
>> Siegfried Goeschl
>>
>>
>>
>>> On 05.07.2020, at 13:42, Daniel Dekany <da...@gmail.com> wrote:
>>>
>>> The reason I was asking is that if all functionality goes in
>> DataSourcers,
>>> the methods will shadow data source names. Like if you have a data source
>>> named "empty", then DataSources.empty will not return that, instead it
>> will
>>> call isEmpty(). That also means that adding new methods to DataSource is
>>> not backward compatible. So probably we will need a separate DataSources,
>>> and DataSourceTool or something. (It's also possible to reverse
>> priorities,
>>> but that's even less manageable for the user.)
>>
>> Thanks, I was not aware of that - let me recap my understanding
>>
>> If I have a data source "empty", e.g. "empty=somepath/some.csv"
>>
>> * DataSources.empty would call DataSources.isEmpty()
>> * DataSources["empty"] would fetch the data source "empty"
>>
>
> Yeah, so thing is, in FreeMarker, foo.bar and foo["bar"] are exactly the
> same. Furthermore, foo.bar() is just foo.bar, and then () operator is
> applied on it's value (which is a method as a first class value).
>
>
>> * DataSources.get("empty") would fetch the data source "empty" since it
>> calls DataSources.get(String)
>>
>
> Yes.
>
>
>> Some thoughts along the line
>>
>> * The names of a list of data sources are not enforced to be unique so the
>> map functionality is slightly broken
>>
>
> Why not? That was also a quite important problem. I guess I even listed it
> in the recent mail... or not. So these names and groups, should be
> consolidated too.
Harvesting directory trees and consolidating the files into a single output - here I can't guarantee that the names are unique
>
>
>> * Tools for me are stateless and can be potentially shared so I can not
>> put the data sources for the current transformation in there
>>
>
> I guess, technically speaking, you can. You are in the context of a
> freemarker-generator run (or whatever the term for that is... session?).
> Where's the ambiguity, or similar issue, if any?
Still want to make the code embeddable so in my mental model the tools are reusable and do not contain "session-specific" data
>
> [snip]
>
> --
> Best regards,
> Daniel Dekany
Re: Help needed for FREEMARKER-148 ...
Posted by Daniel Dekany <da...@gmail.com>.
See my comments inline...
On Sun, Jul 5, 2020 at 2:49 PM Siegfried Goeschl <
siegfried.goeschl@gmail.com> wrote:
> Hi Daniel,
>
> Please see my comments below
>
> Thanks in advance,
>
> Siegfried Goeschl
>
>
>
> > On 05.07.2020, at 13:42, Daniel Dekany <da...@gmail.com> wrote:
> >
> > The reason I was asking is that if all functionality goes in
> DataSourcers,
> > the methods will shadow data source names. Like if you have a data source
> > named "empty", then DataSources.empty will not return that, instead it
> will
> > call isEmpty(). That also means that adding new methods to DataSource is
> > not backward compatible. So probably we will need a separate DataSources,
> > and DataSourceTool or something. (It's also possible to reverse
> priorities,
> > but that's even less manageable for the user.)
>
> Thanks, I was not aware of that - let me recap my understanding
>
> If I have a data source "empty", e.g. "empty=somepath/some.csv"
>
> * DataSources.empty would call DataSources.isEmpty()
> * DataSources["empty"] would fetch the data source "empty"
>
Yeah, so thing is, in FreeMarker, foo.bar and foo["bar"] are exactly the
same. Furthermore, foo.bar() is just foo.bar, and then () operator is
applied on it's value (which is a method as a first class value).
> * DataSources.get("empty") would fetch the data source "empty" since it
> calls DataSources.get(String)
>
Yes.
> Some thoughts along the line
>
> * The names of a list of data sources are not enforced to be unique so the
> map functionality is slightly broken
>
Why not? That was also a quite important problem. I guess I even listed it
in the recent mail... or not. So these names and groups, should be
consolidated too.
> * Tools for me are stateless and can be potentially shared so I can not
> put the data sources for the current transformation in there
>
I guess, technically speaking, you can. You are in the context of a
freemarker-generator run (or whatever the term for that is... session?).
Where's the ambiguity, or similar issue, if any?
[snip]
--
Best regards,
Daniel Dekany
Re: Help needed for FREEMARKER-148 ...
Posted by Siegfried Goeschl <si...@gmail.com>.
Hi Daniel,
Please see my comments below
Thanks in advance,
Siegfried Goeschl
> On 05.07.2020, at 13:42, Daniel Dekany <da...@gmail.com> wrote:
>
> The reason I was asking is that if all functionality goes in DataSourcers,
> the methods will shadow data source names. Like if you have a data source
> named "empty", then DataSources.empty will not return that, instead it will
> call isEmpty(). That also means that adding new methods to DataSource is
> not backward compatible. So probably we will need a separate DataSources,
> and DataSourceTool or something. (It's also possible to reverse priorities,
> but that's even less manageable for the user.)
Thanks, I was not aware of that - let me recap my understanding
If I have a data source "empty", e.g. "empty=somepath/some.csv"
* DataSources.empty would call DataSources.isEmpty()
* DataSources["empty"] would fetch the data source "empty"
* DataSources.get("empty") would fetch the data source "empty" since it calls DataSources.get(String)
Some thoughts along the line
* The names of a list of data sources are not enforced to be unique so the map functionality is slightly broken
* Tools for me are stateless and can be potentially shared so I can not put the data sources for the current transformation in there
Guess I need to think the implications over :-)
>
> Regarding toString() in ${DataSources["github-users.json"].toString()}.
> The model can just implement TemplateScalarModel if we need a default
> string representation, and then it will be just
> ${DataSources["github-users.json"]}. (If you need to expose Java API, plus
> call toString() for TemplateScalarModel, then you can use StringModel as
> the super class.)
No need for that - it was just used for diagnostic output
>
>
> On Sat, Jul 4, 2020 at 10:27 PM Siegfried Goeschl <
> siegfried.goeschl@gmail.com <ma...@gmail.com>> wrote:
>
>> Hi Daniel,
>>
>> Please see the examples in
>> https://issues.apache.org/jira/browse/FREEMARKER-148 <https://issues.apache.org/jira/browse/FREEMARKER-148> <
>> https://issues.apache.org/jira/browse/FREEMARKER-148 <https://issues.apache.org/jira/browse/FREEMARKER-148>>
>>
>> Thanks in advance,
>>
>> Siegfried Goeschl
>>
>>
>>> On 03.07.2020, at 23:25, Daniel Dekany <da...@gmail.com> wrote:
>>>
>>> How do you intend to have map semantics and still expose helper methods?
>>> I'm not asking how would you implement that, but how would it look in the
>>> templates?
>>>
>>> On Tue, Jun 30, 2020 at 9:28 PM Siegfried Goeschl <
>>> siegfried.goeschl@gmail.com> wrote:
>>>
>>>> Hi folks,
>>>>
>>>> Following up a discussion with Daniel I would like to make "DataSources"
>>>> (contains the user-supplied data sources) a bit more FTL friendly
>>>>
>>>> Had a quick look at it but I'm a bit lost
>>>> I created a DataSourcesAdapter which extends TemplateSequenceModel &
>>>> TemplateHashModel
>>>> DataSources has a few additional finder methods which I can't invoke
>> when
>>>> exposing the DataSourcesAdapter
>>>> So the question is what interfaces needs to be implemented to support
>>>> sequence semantics
>>>> hash map semantics
>>>> arbitrary helper methods
>>>> in a single adapter
>>>>
>>>> Thanks in advance,
>>>>
>>>> Siegfried Goeschl
>>>>
>>>>
>>>
>>> --
>>> Best regards,
>>> Daniel Dekany
>>
>>
>
> --
> Best regards,
> Daniel Dekany
Re: Help needed for FREEMARKER-148 ...
Posted by Daniel Dekany <da...@gmail.com>.
The reason I was asking is that if all functionality goes in DataSourcers,
the methods will shadow data source names. Like if you have a data source
named "empty", then DataSources.empty will not return that, instead it will
call isEmpty(). That also means that adding new methods to DataSource is
not backward compatible. So probably we will need a separate DataSources,
and DataSourceTool or something. (It's also possible to reverse priorities,
but that's even less manageable for the user.)
Regarding toString() in ${DataSources["github-users.json"].toString()}.
The model can just implement TemplateScalarModel if we need a default
string representation, and then it will be just
${DataSources["github-users.json"]}. (If you need to expose Java API, plus
call toString() for TemplateScalarModel, then you can use StringModel as
the super class.)
On Sat, Jul 4, 2020 at 10:27 PM Siegfried Goeschl <
siegfried.goeschl@gmail.com> wrote:
> Hi Daniel,
>
> Please see the examples in
> https://issues.apache.org/jira/browse/FREEMARKER-148 <
> https://issues.apache.org/jira/browse/FREEMARKER-148>
>
> Thanks in advance,
>
> Siegfried Goeschl
>
>
> > On 03.07.2020, at 23:25, Daniel Dekany <da...@gmail.com> wrote:
> >
> > How do you intend to have map semantics and still expose helper methods?
> > I'm not asking how would you implement that, but how would it look in the
> > templates?
> >
> > On Tue, Jun 30, 2020 at 9:28 PM Siegfried Goeschl <
> > siegfried.goeschl@gmail.com> wrote:
> >
> >> Hi folks,
> >>
> >> Following up a discussion with Daniel I would like to make "DataSources"
> >> (contains the user-supplied data sources) a bit more FTL friendly
> >>
> >> Had a quick look at it but I'm a bit lost
> >> I created a DataSourcesAdapter which extends TemplateSequenceModel &
> >> TemplateHashModel
> >> DataSources has a few additional finder methods which I can't invoke
> when
> >> exposing the DataSourcesAdapter
> >> So the question is what interfaces needs to be implemented to support
> >> sequence semantics
> >> hash map semantics
> >> arbitrary helper methods
> >> in a single adapter
> >>
> >> Thanks in advance,
> >>
> >> Siegfried Goeschl
> >>
> >>
> >
> > --
> > Best regards,
> > Daniel Dekany
>
>
--
Best regards,
Daniel Dekany
Re: Help needed for FREEMARKER-148 ...
Posted by Siegfried Goeschl <si...@gmail.com>.
Hi Daniel,
Please see the examples in https://issues.apache.org/jira/browse/FREEMARKER-148 <https://issues.apache.org/jira/browse/FREEMARKER-148>
Thanks in advance,
Siegfried Goeschl
> On 03.07.2020, at 23:25, Daniel Dekany <da...@gmail.com> wrote:
>
> How do you intend to have map semantics and still expose helper methods?
> I'm not asking how would you implement that, but how would it look in the
> templates?
>
> On Tue, Jun 30, 2020 at 9:28 PM Siegfried Goeschl <
> siegfried.goeschl@gmail.com> wrote:
>
>> Hi folks,
>>
>> Following up a discussion with Daniel I would like to make "DataSources"
>> (contains the user-supplied data sources) a bit more FTL friendly
>>
>> Had a quick look at it but I'm a bit lost
>> I created a DataSourcesAdapter which extends TemplateSequenceModel &
>> TemplateHashModel
>> DataSources has a few additional finder methods which I can't invoke when
>> exposing the DataSourcesAdapter
>> So the question is what interfaces needs to be implemented to support
>> sequence semantics
>> hash map semantics
>> arbitrary helper methods
>> in a single adapter
>>
>> Thanks in advance,
>>
>> Siegfried Goeschl
>>
>>
>
> --
> Best regards,
> Daniel Dekany