On Fri, Jun 2, 2017 at 5:05 AM, Daniel Dekany <[email protected]> wrote:
> Thursday, June 1, 2017, 5:09:07 PM, Woonsan Ko wrote:
>
>> On Wed, May 31, 2017 at 6:39 PM, Daniel Dekany <[email protected]> wrote:
>>> Wednesday, May 31, 2017, 6:09:32 PM, Woonsan Ko wrote:
>>>
>>>> On Tue, May 30, 2017 at 11:38 AM, Daniel Dekany <[email protected]> wrote:
>>>>> Tuesday, May 30, 2017, 5:02:43 PM, Woonsan Ko wrote:
>>>> <snip>
>>>>>>>>> Speaking of which, soon there will be one. Anyone is interested in FM3
>>>>>>>>> Spring integration? The goal is that FM3's builder-based configuration
>>>>>>>>> can be used seamlessly for creating the Spring beans. So certainly a
>>>>>>>>> freemarker-spring module need to be added, which extends some classes
>>>>>>>>> to implement FactoryBean interface and such. Also some configuration
>>>>>>>>> defaults, like the TemplateLoader need to be different for sure, and
>>>>>>>>> we need a TemplateLoader that uses Spring's Resource API. (I will
>>>>>>>>> create an issue for it after I have polished the configuration API a
>>>>>>>>> bit more.)
>>>>>>>>
>>>>>>>> Yes, I am interested in FM3 spring integration.
>>>>>>>> One question is, are we going to replace spring framework's default
>>>>>>>> freemarker view support [1] by freemarker-spring in FM3?
>>>>>>>
>>>>>>> That would be the idea. And that will be the only possibility at the
>>>>>>> beginning, as they only have FM2 support (and I guess contributing to
>>>>>>> ASF/FM makes more sense than contributing to them).
>>>>>>
>>>>>> OK, got it.
>>>>>>
>>>>>>>
>>>>>>>> Anyway, I'll happily help with this as soon as you create an issue.
>>>>>>>
>>>>>>> Great! That will happen in a few days.
>>>>>>
>>>>>> I will try to list features of spring framework support for
>>>>>> compatibility and other possible new features and improvements first.
>>>>>> And, I'll try to discuss those items here soon.
>>>>>
>>>>> Sounds good.
>>>>
>>>> I've reviewed spring online documentation and tried to list all the
>>>> features currently supported. We'll probably need to provide
>>>> compatible solutions or alternatives for FM3. I added some notes on
>>>> some items, too. Prioritization wasn't considered yet.
>>>>
>>>> -----
>>>>
>>>> 1. Configuration support
>>>>
>>>> 1.1. Generic Configuration Factory bean support (that can be used for
>>>> non web-apps)
>>>>   - FreeMarkerConfigurationFactoryBean
>>>>   - Note: perhaps the builder should be used internally inside the factory 
>>>> bean?
>>>
>>> The FactoryBean should extend Configuration.ExtenableBuilder. So it's
>>> not even some internal stuff; ExtenableBuilder is public and was added
>>> for things like this.
>>>
>>>> 1.2. Web MVC Configurer bean support
>>>>   - FreeMarkerConfigurer
>>>
>>> Ah that... whole thing. It's really confusing. It starts there that
>>> it's hard to grasp for the user what a FreeMarkerConfigurer really is.
>>> Because, we already have Configuration, and even a Spring-specific
>>> class, FreeMarkerConfigurationFactoryBean that creates that. To
>>> configure FreeMarker you need a Configuration, so a Configuration is
>>> the real "FreeMarker configurer". But the "FreeMarkerConfigurer" name
>>> suggests the same ("I configure FreeMarker"). So how is it different?
>>> To make it more confusing, it's basically
>>> FreeMarkerConfigurationFactoryBean (which is just a Configuration
>>> Builder) with a few quirks:
>>>
>>> - It's technically not a FactoryBean. So instead of relying on Spring IoC
>>>   injection as usual, the dependent bean (FreeMarkerViewResolver
>>>   usually) has to call getConfiguration() on it.
>>>
>>> - getConfiguration() might returns a Configuration that wasn't built by
>>>   the FreeMarkerConfigurer! If you call setConfiguration(Configuration),
>>>   then that Configuration will be returned, and things you set on
>>>   FreeMarkerConfigurer (which is a Configuration Builder) doesn't
>>>   mater. Anyway, you would (or just I would?) think that if you want
>>>   the Web View stuff to use a specific Configuration, then you just inject
>>>   that Configuration bean into FreeMarkerViewResolver. But no, because
>>>   FreeMarkerViewResolver needs a FreeMarkerConfigurer. In fact,
>>>   FreeMarkerViewResolver doesn't need that directly. Instead, it just
>>>   specifies a class, FreeMarkerView, which in turn "manually" looks up
>>>   the FreeMarkerConfigurer bean with BeanFactoryUtils.
>>>
>>> - It provides a TaglibFactory object as well. I have to give that to
>>>   it, as that's at least something that Configuration doesn't do. But
>>>   if that will be the only obstacle of getting rid of
>>>   FreeMarkerConfigurer, then we stuff that into the Configuration,
>>>   like as a custom attribute (custom setting, if I have renamed it as
>>>   discussed), and as a real JavaBean property in our ExtenableBuilder
>>>   subclass.
>>>
>>> BTW Velocity support have the same hard to follow logic. Maybe it's
>>> necessary, I don't know. Still, I wonder if we can make it more
>>> elegant and less confusing for users. (Is it nicer with Thymeleaf for
>>> example?) What I'm hoping for is that we can just use a Configuration
>>> bean instead, and FreeMarkerView looks that up. The tricky part is how
>>> to differentiate that bean from the other Configuration beans. The
>>> natural solution is using a "web" qualifier, which is easy to follow
>>> for the user as well (no magic, it's obvious how it works). But some
>>> may feel it's not very stream lined (because I believe we can't
>>> transparently make a bean qualified, so the user has to add it to its
>>> configuration). So another possibility is subclassing Configuration,
>>> so then we first look for a WebConfiguration (and then of course we
>>> will also need a FreeMarkerWebConfigurationFactoryBean - note the
>>> "Web" in it), and only if that's not found we look for "web" qualified
>>> Configuration. But maybe all this is too different from Spring
>>> tradition... I'm just thinking aloud.
>>
>> I will look into it further. But in general, the current
>> FreeMarkerConfigurer based configuration looks confusing to me, and as
>> you pointed out it's not even a FactoryBean and it's found out by the
>> view resolver, etc. I feel like it could be neater. Let me investigate
>> other things further and come back.
>>
>>>
>>> BTW, I believe e-mail generation and other miscellaneous FreeMarker
>>> applications (report generation, etc.) will be at least as important
>>> as web pages nowadays.
>>
>> +1
>>
>>>
>>>>  and FreeMarkerViewResolver (basically extending UrlBasedViewResolver)
>>>>   - Note: the view resolver finds out the configurer bean by type by
>>>> default.
>>>
>>> Well, if we stick to the approach with FreeMarkerConfigurer and all
>>> that, the it's good enough. Otherwise see above.
>>>
>>>> Seems good enough for normal web application to me. Same
>>>> pattern in the configurer by using builder internally?
>>>
>>> (The builders aren't meant to be internal, but it's the same as
>>> earlier.)
>>>
>>>> 1.3. Annotation / XML Schema based configuration support
>>>> (FreeMarkerConfigurer type bean)
>>>>   - Note: ViewResolverRegistry#freemarker() finds a bean by exact type
>>>> of FreeMarkerConfigurer. alternative?
>>>
>>> What can we do about this at all? I mean, we can't add methods to this
>>> class.
>>
>> Yeah. We may lose @EnableWebMvc feature since it seems tightly coupled
>> with FreeMarkerConfigurer. Indeed, ViewResolverRegistry is created in
>> a hard-coded way directly by WebMvcConfigurationSupport.
>
> Yet again, it might worth checking out what the Thymeleaf guys did, as
> they focus heavily on Spring integration.

OK. That sounds right. I'll take a look at how they do.

>
>>>
>>>>     (ref:
>>>> http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#mvc-config-view-resolvers)
>>>>
>>>> 1.4. XML Schema based configuration support
>>>>   - Note: alternative for this?
>>>>   <mvc:view-resolvers>
>>>>     <!-- SNIP -->
>>>>     <mvc:freemarker cache="false"/>
>>>>   </mvc:view-resolvers>
>>>
>>> XML config is low priority, I guess.
>>
>> +1
>>
>>>
>>>> 2. View Resolution support
>>>>   - FreeMarkerViewResolver and FreeMarkerView
>>>>
>>>> 3. Tempplating Support
>>>>
>>>> 3.1. JSP Tag Libraries support
>>>>   - Spring / Spring form tag libraries and Spring binding macro support.
>>>>   - Note: It looks like spring macros (spring.ftl) are duplicate
>>>> effort to the JSTL tag libraries, so I'm wondering if the macros were
>>>> originally introduced before freemarker JSTL tag library support
>>>> wasn't there or wasn't good enough. If so, perhaps can we stick to
>>>> using JSTL tag libraries directly without having to rewrite/provide
>>>> the macros?
>>>>     Or would it bring huge disruption in spring-mvc/freemarker community?
>>>>     Need to validate it more...
>>>
>>> So I guess that's where my domain knowledge ends. Which JSTL tags are
>>> these? The Spring macros I have seen in SO questions and such call
>>> Spring-specific functionality, not JSTL... or I just don't know what
>>> JSTL can do. (Basic JSTL tags/functions are often duplicates core
>>> FreeMarker functionality, like c:if, c:forEach, etc.) BTW, many JSTL
>>> tags actually don't work with FreeMarker JSP support (I remember we
>>> have a test case on @Ignore which demonstrates that). Pretty much only
>>> traditional custom JSP tags do.
>>
>> I'm sorry for my confusion. I should have used (spring custom) "JSP
>> tags", not "JSTL tags".
>>
>> Examples of "duplicate efforts" to me:
>> - In Spring JSP Taglibs
>> (https://docs.spring.io/spring/docs/current/spring-framework-reference/html/spring-tld.html),
>> it has 'message' tag.
>>   In spring.ftl, it also has 'message' macro and variants
>> ('messageArgs', 'messageArgsText', ...).
>>   Perhaps there is a little to help with the macros, but developers
>> can use jsp tag lib in ftl directly.
>> - In Spring Form Taglibs
>> (https://docs.spring.io/spring/docs/current/spring-framework-reference/html/spring-form-tld.html),
>> it has 'checkboxes' tag.
>>   spring.ftl defines macros too for the same functionality.
>>
>> So, I'm thinking if we can stick with JSP taglibs only, then we might
>> not need to support those macros separately.
>
> I hope (but haven't checked) that Spring has a
> view-technology-independent layer of this, and then the JSP custom
> tags (and FreeMarker macros) are just adapting that to the conventions

Ah, yes. That's something to check. Good point.

> of the view technology (JSP, FTL). My concern with simply solving it
> with yet another adapter layer (FTL to JSP) is that the logic of at
> least some of these JSP tags is foreign from (modern) FTL. And the
> same certainly goes for other view technologies as well (here again
> it's might be a good idea to look what they did at Thymeleaf).

OK.

>
> Let's take spring:message for example. Why's this a tag at all? It's
> function, or even just a hash. If I had to expose such functionality
> to FTL-s, it would look like `${messages.hello}` and
> `${messages.hello(userName)}` and `${messages.hello(arg1, arg2,
> argN)}`. This also means that you can pass a resolved message as an
> argument to another macro/function: `<@foo messages.hello(userName)>`.
> And what's up with the escaping parameters? Because normally HTML
> autoescaping is ideally on, users has to do nothing to escape, and
> they can write ${messages.thisIsAlreadyHTML?noEsc} otherwise. We
> leverage core FTL functionality here, not need for any extra
> `messages` parameter for that. (Not to mention that in general it's
> not good that the user who inserts the message has to know if it's
> already HTML or not. I mean they can't decide it there, because it's
> already either HTML or plain text in the message data source. So,
> `messages` should know that (the data source should store that
> meta-information somehow). Then, `message.foo` returns an FTL String
> if `foo` is plain text, and FTL HTML markup-output if `foo` is HTML
> message, hence there's no need for ?noEsc in the last case, as
> FreeMarker knows that it needs no further escaping.
>
> In the future we might run into other cases where we can't utilize FTL
> features because the JSP obviously doesn't do that, and hence they
> have duplicated it, or just don't have it.
>
> There are also cases of the opposite of it, i.e., where JSP can do
> something that we can't, or at least it ugly and not idiomatic. Take
> for example the `var` and `scope` attributes of the spring:messages
> tag. Well, FTL has no out-parameters, nor scopes (even if the
> FreemarkerServlet data-model emulates the last to an extent). But if
> we solve this functionality with a function, as we should anyway (see
> above), we return that thing, so we don't need an out-param. If
> instead we just call spring:message with the JSP custom tag support of
> FreeMarker, it won't magically transform it to a function.

Good point! Sound better with extra ftl macros, not depending only on JSP tags.

>
>>>> 3.2. HTML escaping and XHTML compliance??
>>>>   - ref:
>>>> http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#views-form-macros-html-escaping,
>>>>
>>>> https://docs.spring.io/spring/docs/current/spring-framework-reference/html/spring-form-tld.html
>>>>
>>>>   - Note: If we stick with JSTL tags without any extra macros (3.1), I
>>>> guess we won't need this special variable settings for escaping any
>>>> more..
>>>
>>> So this is about how Spring (or you are saying, JSTL?) generated HTML
>>> fragments use escaping internally.
>>
>> Sorry again, I should have said 'spring jsp tag libraries' instead.
>> For example, the 'message' tag already has 'htmlEscape' attribute. So,
>> when using the tag, ftl can use that attribute directly.
>> By the way, 'htmlEscape' spring jsp tag wouldn't be used in .ftl,
>> practically speaking as FM provides a better support.
>
> Yip.
>
>>>> 4. Testing support
>>>>   - ref:
>>>> http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#spring-mvc-test-server-htmlunit
>>>>   - Note: Make sure it works...
>>>>
>>>> 5. Micellaneous
>>>>
>>>> 5.1. Sending E-Mail support
>>>>   - ref:
>>>> http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#mail-templates-example
>>>>   - Note: might be a low-hanging fruit by giving an example with
>>>> freemarker instead...
>>>
>>> Yeah... especially if they will ever switch to freaking post-2.3.23
>>> FreeMarker (they don't upgrade since we are incubating...), because
>>> auto-escaping is missing from that example, and 2.3.24 does it much
>>> better than 2.3.23.
>>>
>>>> -----
>>>>
>>>> Personally, I wish to have the following in the future too:
>>>>
>>>> 6. More wishes
>>>>
>>>> 6.1. Generic FreeMarker Configuration Factory with JSTL support
>>>>   - I have an HMVC web application framework which uses spring
>>>> framework as IoC, not MVC and Freemarker as view templating, but it
>>>> needs to support JSTL tag libraries. So far I have dispatched requests
>>>> to Freemarker servlet. I wish to configure a configuration factory and
>>>> use the service somehow directly without having to use request
>>>> dispatching any more...
>>>
>>> Not sure I follow, but isn't this using JSP support without
>>> FreemarkerServlet? It's not well documented, but possible, like Spring
>>> MVC does that too.
>>
>> Oh yeah?
>
> I'm not entirely sure... It think so as FreeMarkerConfigurer stores a
> TaglibFactory.

Yeah, I think I took a glance at that. Will look into it further.

After studying how Thymeleaf guys do further, I can probably share better ideas.

Regards,

Woonsan

>
>> That's good then. I'll try it later.
>
>> Thanks for all your input! I'll look into more detail and discuss further 
>> later.
>>
>> Cheers,
>>
>> Woonsan
>>
>>>
>>>> -----
>>>>
>>>> Folks, if you have experienced with spring + freemarker, please
>>>> review/correct my understandings and chime in here.
>>>> Also, it is probably a good time to speak up if you wish to have in
>>>> the future. ;-)
>>>>
>>>>>
>>>>> I was a bit boggled down with the configuration API polishing, so I
>>>>> haven't yet made the Jira issue. But I belive there's enough things to
>>>>> do with the Spring integration before that becomes a problem. Things
>>>>> will keep changing under it anyway. But that's just how refactoring
>>>>> goes, and the same will happen again and again with freemarker-dom and
>>>>> freemarker-servlet too.
>>>>
>>>> Yes, I think this spring framework support could be started in
>>>> separate feature branch(es).
>>>> I guess the most important ones from the list above are 1.1, 1.2, 2, and 
>>>> 3.1.
>>>> Perhaps I can start working for those 4 items first in my github
>>>> branch to merge it later.
>>>> If there are other people who want to contribute to any of those, we
>>>> can consider a shared feature branch instead...
>>>>
>>>>>
>>>>> The goal would be not using the setSetting(String, String) API when
>>>>> configuring under Spring, and work with beans and bean properties
>>>>> cleanly. Ideally, only the builder classes need to be subclassed to
>>>>> add some Spring annotations/interfaces and Spring-specific defaults.
>>>>
>>>> I see. And I saw your builder class is really extensible. That's great!
>>>>
>>>>>
>>>>> One thing that I will surely want to do in FM3 is allowing mixed
>>>>> positional and named parameters in templates, like `f(1, 2, foo=3,
>>>>> bar=4)` or `<@m 1, 2 foo=3 bar=4/>`. That's probably good to know when
>>>>> it comes to calling Spring features from templates. (Of course this
>>>>> will require replacing TemplateMethodModel and TemplateDirectiveModel
>>>>> etc. with something better. Cleaning up the mess around the callable
>>>>> objects is part of FM3 anyway.)
>>>>
>>>> Sounds good. I haven't found a good example of 'calling Spring
>>>> features from templates' yet though. Maybe I'm missing something
>>>> important...
>>>>
>>>> Regards,
>>>>
>>>> Woonsan
>>>>
>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Woonsan
>>>>>>
>>>>>>>
>>>>>>>> Regards,
>>>>>>>>
>>>>>>>> Woonsan
>>>>>>>>
>>>>>>>> [1]
>>>>>>>> https://docs.spring.io/spring/docs/current/spring-framework-reference/html/view.html#view-velocity-contextconfig
>>>>>>>>
>>>>>>>>>
>>>>>>>>>> Best regards,
>>>>>>>>>>
>>>>>>>>>> Michael Brohl
>>>>>>>>>> ecomify GmbH
>>>>>>>>>> www.ecomify.de
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Am 17.05.17 um 14:29 schrieb Daniel Dekany:
>>>>>>>>>>> Wednesday, May 17, 2017, 2:26:29 AM, Taher Alkhateeb wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Yeah I closed it because it was a proposal for a PoC which you 
>>>>>>>>>>>> pretty much
>>>>>>>>>>>> got done while I slacked :) Should I re-open? If yes then perhaps 
>>>>>>>>>>>> it should
>>>>>>>>>>>> be renamed by removing the "PoC" part?
>>>>>>>>>>> No, then it was right to close it after all. You can create an issue
>>>>>>>>>>> for resolving the TODO-s and polishing the stuff it you think, 
>>>>>>>>>>> though
>>>>>>>>>>> honestly FM3 has tons and tons of non-Jiraed things to do... What
>>>>>>>>>>> really counts if someone is interested in actually working on them.
>>>>>>>>>>> (I'm not saying this to point at you or anyone. It's unpaid work 
>>>>>>>>>>> etc.,
>>>>>>>>>>> and if the project can't attract contributors, it's the fault of the
>>>>>>>>>>> project and of its key persons, like me. The aspect that concerns me
>>>>>>>>>>> is that if I do all the technical stuff, even if I was some kind of
>>>>>>>>>>> superhuman one man army (and BTW I'm not) who can grind through
>>>>>>>>>>> everything in time regardless, that will be a serious problem when 
>>>>>>>>>>> it
>>>>>>>>>>> comes to Apache incubation voting...)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>> On Tue, May 16, 2017 at 11:10 PM, Daniel Dekany 
>>>>>>>>>>>> <[email protected]> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> I saw the Jira issue for migrating to Gradle was closed, but to be
>>>>>>>>>>>>> clear it's far from done. Like, a major TODO is building the 
>>>>>>>>>>>>> release
>>>>>>>>>>>>> artifacts; the root project should do that (or should that be yet
>>>>>>>>>>>>> another sub-project instead?).
>>>>>>>>>>>>>
>>>>>>>>>>>>> The second most important deficiency is producing all the 3 Maven
>>>>>>>>>>>>> artifacts for each published module (the usual artifact plus src 
>>>>>>>>>>>>> and
>>>>>>>>>>>>> javadoc). Currently we only produce one artifact per module, and 
>>>>>>>>>>>>> it's
>>>>>>>>>>>>> not even signed.
>>>>>>>>>>>>>
>>>>>>>>>>>>> BTW, I have factored out Manual generation into freemarker-manual
>>>>>>>>>>>>> (non-published module). There's also a TODO there as its build 
>>>>>>>>>>>>> doesn't
>>>>>>>>>>>>> produce anything yet.
>>>>>>>>>>>>>
>>>>>>>>>>>>> --
>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>   Daniel Dekany
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Thanks,
>>>>>>>>>  Daniel Dekany
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Thanks,
>>>>>>>  Daniel Dekany
>>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> Thanks,
>>>>>  Daniel Dekany
>>>>>
>>>>
>>>
>>> --
>>> Thanks,
>>>  Daniel Dekany
>>>
>>
>
> --
> Thanks,
>  Daniel Dekany
>

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