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<div class="moz-cite-prefix">Here we have an interesting interaction
between the ordering of compiler phases.<br>
<br>
Ur/Web links (including in <submit> actions) must be calls
to named functions defined at the top levels of modules, more or
less. While the body of [sbm] instead uses a local variable for a
link, we know, of course, that inlining the definition of [sbm]
leads to a concrete function name instead. Unfortunately, the
current Ur/Web compiler is not going to inline the call, because
the phase that does inlining runs <i>after</i> the phase that
produces URL-generation code! I think this ordering choice is
actually the right one, because inlining can change which
syntactic function name appears in an 'action' attribute, etc.,
potentially leading to unintuitive behavior in URL generation
(e.g., a link written as a call to a particular named function
actually winds up compiled as a call to different named function,
because of inlining).<br>
<br>
Probably the easiest way to implement your abstraction is via a
functor, using the module system. Functor applications get
inlined fully before producing URL-generation code.<br>
<br>
Even better, though, could be to stop using 20th-century forms and
use client-side scripting with <button>, etc., instead!<br>
<br>
On 07/20/2014 04:08 PM, Sergey Mironov wrote:<br>
</div>
<blockquote
cite="mid:CAMOkk_ac2WGwLV9dfrR-rcFJ-EdFANgU=rJpiOzuoRtWGKExqQ@mail.gmail.com"
type="cite">
<pre wrap="">Hi! Here is another error I've faced when trying to write a
styling-wrapper for my submit buttons:
$ urweb -dbms sqlite Submit
/home/grwlf/proj/urbugs/Submit.ur:21:89: (to 21:90) Invalid Action expression
Expression UNBOUND_0
See the trivial example below. Please, consider fixing! Without
sbm-like wrappers I am forced to repeat submit code from form to
form..
Regards,
Sergey
--
style mystyle
con ct = [A = string, B = string]
fun handler (x:$ct) : transaction page = return
<xml><head/><body>{[x.A]}{[x.B]}</body></xml>
fun sbm [t:::{Type}] (h : $t -> transaction page) : xml form t [] =
<xml><div class={mystyle}><submit action={h}
value="Send"/></div></xml>
fun main {} = return <xml><head/><body>
<br/>
<form>
<textbox{#A}/>
<textbox{#B}/>
{sbm handler}
</form>
</body></xml>
</pre>
</blockquote>
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