Saturday, March 24, 2018, 4:33:01 PM, Woonsan Ko wrote:
> Hi folks,
>
> I'd like to bring this topic again to our attention.
> It started totally my own mistake by being confused "Square bracket
> tag syntax" (since 2.3.4) with the new "Square bracket interpolation
> syntax" (since 2.3.28). [1]
> Here's my example in another thread [2]:
>
> 1: [#ftl output_format="HTML"]
> 2: [#assign a=[1,2,3]]
> 3: [="Hello"]
>
> #1 and #2 work as they are using the "Square bracket tag syntax", but
> #3 doesn't by default (unless you change the configuration to use
> "Square bracket interpolation" option).
> So, it should have been like the following for intention:
>
> 1: [#ftl output_format="HTML"]
> 2: [#assign a=[1,2,3]]
> 3: ${"Hello"}
>
> Now, I'm wondering if this kind of confusion could happen more to other
> people.
> When they use square bracket tag syntax, they might be easily doing
> the same thing for the interpolation like the first example.
>
> One possible solution could be to use mustache as the default
> alternative for interpolation like this:
>
> 1: [#ftl output_format="HTML"]
> 2: [#assign a=[1,2,3]]
> 3: {{"Hello"}}
>
> As interpolation's alternative syntax is to use mustache, it might be
> less confusing by not using the same syntax for both tags and
> interpolation.
> My old reason why avoiding mustache was, Javascript framework could
> use both '${something}' [3] and '{{something}}' together. But also if
> someones adopts mustache style JS frameworks, they might not use the
> technique like [3]. Not sure though...
After re-reading and re-thinking the thread, I'm back to the opinion
that fighting the confusion arousing from the mere coincidence that
both things are "square bracket" is the better compromise:
- While using {{...}} in output is not very frequent, when it's used
in the output, there's a quite real chance that the output also uses
${...}. A lot of languages and formats use ${...}, now including the
omnipresent JavaScript, and so ${...} will become more frequent in
web pages in the future. So, if you generate Angular pages for
example, it's quite possible that they use both... and then what
will you do?
- Using square bracket tag syntax together with square bracket
interpolation syntax makes template-templates (a template of a
template, be it FreeMarker template, JSP, etc.) easy to read, as
your visual cortex can just hunt for the [...]-s. It matters because
template-templates tend to be already messy, I guess.
BTW, I have discovered a slight drawback of [=...] while using it.
Instead of ${x} you write [=x], fine. But what do you write instead of
${x + 1}? The logical one is [=x + 1], but its spacing is ugly, so I
think it's going to be [= x + 1]. One more space. Yeah, quite a nick
picking, but just so you know about it...
> Another possible option could be to allow to change the interpolation
> syntax to square bracket automatically as well if the first [#ftl ...]
> is used like the tag syntax's automatic switching per template.
> But I'm not sure what the implication is behind about this.
Templates that did work earlier won't, which is a pretty concrete
implication. (: I wish we only had <#>+${} and [#]+[=] from the
beginning, but now we can't do that. Not in FM2 at least. Maybe we
should do that in FM3. Actually, yeah, it would be much easier if one
can just chose a "template syntax", not a "tag syntax" and an
"interpolation syntax".
> What do you think? Would my confusion be ignorable or do we need to
> think about the alternative interpolation syntax again?
It's not ignorable, but there are multiple ways of countering this. My
grand plan (: is that some people will do that oversight you did, but
they will realize pretty quickly that something is wrong (it's not the
kind of problem that can remain hidden), and then they will ask
Google, and hopefully will not be able to avoid the "notices" I stick
every place where we are talking about square brackets. How about
that?
> Kind regards,
>
> Woonsan
>
> [1]
> https://freemarker.apache.org/builds/fm2.3.28/dgui_misc_alternativesyntax.html
> [2]
> https://lists.apache.org/thread.html/2372e673c5b8bd91150f7dd43319786dda8af38acdef87cd37f09ead@%3Cdev.freemarker.apache.org%3E
> [3] https://en.wikipedia.org/wiki/String_interpolation#JavaScript
>
> On Fri, Dec 15, 2017 at 5:28 AM, Daniel Dekany <[email protected]> wrote:
>> OK, so I would go for [=exp] (see the reason told in this thread). How
>> acceptable is that guys?
>>
>>
>> Tuesday, December 5, 2017, 11:56:59 AM, Woonsan Ko wrote:
>>
>>> On Mon, Dec 4, 2017 at 10:28 AM, Daniel Dekany <[email protected]> wrote:
>>>> Monday, December 4, 2017, 10:21:48 AM, Taher Alkhateeb wrote:
>>>>
>>>>> uh-huh, but I suspect maybe more collisions or need to escape
>>>>> character in something like [this] or <this> than {{this}}. Anyway,
>>>>> nothing critical IMO, only thinking out loud.
>>>>
>>>> But they were [=this] and <=this>, so the sequences that will clash
>>>> are "[=" and "<=", which are quite rare. Oh wait... "<=" is not rare
>>>> at all: "if (x <= y)". But "[=" still is. OK, so I guess at this point
>>>> the two competitors left are {{exp}} and [=exp] (regardless of tag
>>>> syntax).
>>>
>>> +1.00 on [=exp].
>>> +0.49 on {{exp}}.
>>>
>>> :-D
>>>
>>> Many languages or templates allows ${exp}, including JavaScript. [1]
>>> And, mustache is supported in many languages or templates, too. [2]
>>> Therefore, I think there are more chances using both ${exp} and
>>> {{exp}} in output we want to generate in the future.
>>> The mustache style looks charming at the moment, but I wonder how its
>>> charming can help for the original intention (to avoid any possible
>>> collision in the output we want to generate by an alternative as much
>>> as we can).
>>>
>>> Regards,
>>>
>>> Woonsan
>>>
>>> [1] https://en.wikipedia.org/wiki/String_interpolation
>>> [2] https://mustache.github.io/
>>>
>>>>
>>>>> On Mon, Dec 4, 2017 at 12:00 PM, Daniel Dekany <[email protected]> wrote:
>>>>>> Monday, December 4, 2017, 9:17:34 AM, Taher Alkhateeb wrote:
>>>>>>
>>>>>>> So maybe a safe bet (and a familiar one) is the mustache syntax.
>>>>>>>
>>>>>>> In addition to avoiding clashes it might help with a multi-chained
>>>>>>> template. For example, we use FreeMarker extensively in Apache OFBiz
>>>>>>> to generate many documents including XML. Now our XML documents might
>>>>>>> contain some ${variable} that needs to be interpreted in the XML
>>>>>>> parser, not the freemarker parser (without having to escape characters
>>>>>>> everywhere)
>>>>>>
>>>>>> Though that also works with all the other proposal syntaxes as well.
>>>>>>
>>>>>>> On Mon, Dec 4, 2017 at 8:50 AM, Jacques Le Roux
>>>>>>> <[email protected]> wrote:
>>>>>>>> Le 03/12/2017 à 22:06, Woonsan Ko a écrit :
>>>>>>>>>
>>>>>>>>> It is also most productive as no shift key is required.
>>>>>>>>
>>>>>>>> Depends on keyboard, for French keyboard type (azerty) you need to use
>>>>>>>> Alt
>>>>>>>> key ;)
>>>>>>>> Same for {{...}} anyway
>>>>>>>>
>>>>>>>> Jacques
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> Thanks,
>>>>>> Daniel Dekany
>>>>>>
>>>>>
>>>>
>>>> --
>>>> Thanks,
>>>> Daniel Dekany
>>>>
>>>
>>
>> --
>> Thanks,
>> Daniel Dekany
>>
>
--
Thanks,
Daniel Dekany
