Surround with not working when using ChooseTemplate for mobile

[Kevin]

Hi there, I've created a fork of lift_25_sbt to show a problem I'm having where I use a snippet to choose either a normal template or a mobile phone template. The snippet is working, but the content is not being replace by pages with a surround.

Here is the fork: https://github.com/kevg/lift_25_sbt

And here is the diff: https://github.com/kevg/lift_25_sbt/commit/c8803daf95c6e007409de672e1dcb5231d97177a

I changed the default template to be the ChooseTemplate based on David's suggestion: https://groups.google.com/d/msg/liftweb/g1Co9wvvbBM/mpZymarR06AJ

<div class="lift:ChooseTemplate">
  <div id"normal" class="lift:embed?what=normal_template"></div>
  <div id="mobile" class="lift:embed?what=mobile_template"></div>
</div>

When I run the code, I get "The main content will get bound here" instead of the content of the page. Any thoughts?

Thanks,
Kevin

[Diego Medina]

Could you try using eager=true  ? I'm on my cell and i can't remember if it goes on the outer snippet or the inner.

Regards

Diego

Diego
Sent from my android cell

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[AGYNAMIX Torsten Uhlmann]

eager_eval="true" needs to be added to the outer snippet...

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[Kevin]

Hi Diego, Torsten, I tried adding eager_eval=true on both the outer snippet and the embed tags, and neither worked:

    <div class="lift:ChooseTemplate?eager_eval=true">
      <div id="normal" class="lift:embed?what=normal_template"></div>

      <div id="mobile" class="lift:embed?what=mobile_template"></div>
    </div>

    <div class="lift:ChooseTemplate">

      <div id="normal" class="lift:embed?what=normal_template;eager_eval=true"></div>
      <div id="mobile" class="lift:embed?what=mobile_template;eager_eval=true"></div>
    </div>

    <div class="lift:ChooseTemplate?eager_eval=true">
      <div id="normal" class="lift:embed?what=normal_template;eager_eval=true"></div>
      <div id="mobile" class="lift:embed?what=mobile_template;eager_eval=true"></div>
    </div>

[Diego Medina]

Thanks Torsten,

@Kevin: This is very strange, could you put together a sample app showing this?
https://www.assembla.com/wiki/show/liftweb/Posting_example_code

I have used eager_eval before to solve this issue, so I hope it is not broken.

Thanks

Diego

--
Diego Medina
Lift/Scala Developer
di...@fmpwizard.com
http://www.fmpwizard.com

[Kevin]

Hey Diego, thanks very much for taking a look! The reproduced problem is in the lift_blank project here:

git clone git://github.com/kevg/lift_25_sbt.git

The diff for the changes I made are here: https://github.com/kevg/lift_25_sbt/commit/c8803daf95c6e007409de672e1dcb5231d97177a

[AGYNAMIX Torsten Uhlmann]

Hi Kevin,

in the code I nowhere see an eager_eval, did you miss it?

In the Lift source (SnippetSpec) it is embedded like this:

<div class="l:foo?eager_eval=true">a<lift:foo>b</lift:foo></div>

Kind Regards,

Torsten.

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AGYNAMIX(R). Passionate Software.
Inh. Torsten Uhlmann | Buchenweg 5 | 09380 Thalheim
Phone:       +49 3721 273445
Fax:             +49 3721 273446
Mobile:       +49 151 12412427
Web:           http://www.agynamix.de

[Kevin]

Hi Torsten, I had just tested eager_eval=true and it didn't work but I didn't commit eager_eval=true. The change is committed now with:

    <div class="lift:ChooseTemplate?eager_eval=true">                                                                                                                          
       <div id="normal" class="lift:embed?what=normal_template"></div>                                                                                                          
       <div id="mobile" class="lift:embed?what=mobile_template"></div>                                                                                                          
     </div>

[Diego Medina]

ok, I pulled the latest from your branch,

I go to http://127.0.0.1:8080/index?mobile=true and the page is just
blank, is this what you see too? can you get even a regular snippet
working?

I guess having detail steps on what we should do to see what you see,
and details on what you see, but expect to see would help.

Thanks

Diego

[Kevin]

Hi Diego, That's the problem. If you remove eager_eval=true, then you won't see a blank screen, but the "content" div will not be updated with the actual page contents (although the correct template embed is chosen based on mobile=true).

The basic problem is that I would like to select a template based on some boolean logic to test whether a request is coming from a mobile phone or not. I had used David's example of a snippet that chooses the correct embed and I'm unable to make it work with any combination of eager_eval. However, if there's an alternative way to do this, that is just as good.

Thanks.

[Diego Medina]

Ah, ok, I'll try again tonight then :)

Diego

[Diego Medina]

ok, so I could not get eager_eval to do what I wanted, so I ended up
with a different solution

https://github.com/fmpwizard/lift_25_sbt/commit/40383f9add27082c59ec656d964dc03d19a41602

Hope that helps.

Diego

[AGYNAMIX Torsten Uhlmann]

Clever.

-- 

AGYNAMIX(R). Passionate Software.
Inh. Torsten Uhlmann | Buchenweg 5 | 09380 Thalheim
Phone:       +49 3721 273445
Fax:             +49 3721 273446
Mobile:       +49 151 12412427
Web:           http://www.agynamix.de

[Diego Medina]

Thanks

Diego
Sent from my android cell

[Kevin]

Sorry, I didn't get an email notification about this reply. Thanks very much for getting it to work!

[Peter Petersson]

A question still reminds in my head, why did not  eager_eval work ? I am on my cell and have not looked at the code but I think both you and Torsten was right on track when you suggested it.

--from my cell
best regards Peter Peterson

[Diego Medina]

On Wed, Oct 17, 2012 at 5:38 PM, Peter Petersson
<peterss...@gmail.com> wrote:
> A question still reminds in my head, why did not eager_eval work ? I am on
> my cell and have not looked at the code but I think both you and Torsten was
> right on track when you suggested it.
>

a wild guess is that the surround snippet works differently than a
regular snippet, but I haven;t had the chance to look any further.

Diego

[David Pollak]

The surround snippet eagerly evaluates the thing being surrounded before putting it inside the template. That way, stuff like messages, etc. get displayed correctly.

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[Diego Medina]

Thanks fir the clarification.

Diego