Re: blocks in Lua (was Re: [PROPOSAL] [PATCH] simple method call)

[Coda Highland <chighland@...>]

On Tue, Jun 16, 2015 at 2:08 PM, Aapo Talvensaari
<aapo.talvensaari@gmail.com> wrote:
> On 16 June 2015 at 23:51, Aapo Talvensaari <aapo.talvensaari@gmail.com>
> wrote:
>>
>> > I'm quite happy with lua-resty-validation but a few things needs to be
>> > resolved still. E.g. those that I mentioned in my previous post in this
>> > thread.
>
>
> Those problems were:
>
> 1. How should I implement "optional" filters (and what to do with them, skip
> or continue with next, or should this be parameterized somehow)
> 2. How should I implement "stop" filters (aka those that skip rest of the
> chain)
> 3. How should I implement "default" values (do I need to have this by
> filters or by filter chain or both)
> 4. Should I split validation (e.g. true/false checks) and filters (those
> that modify values) – righth now my implementation supports validators,
> filters and validating filters (but this might look too much magic).
> 5. How should I handle absent values (missing values and nils don't
> neccessarely mean that something is wrong with input, see below).
>
>
> And also a few other probems:
>
> 6. Allow validation / filtering on some other value only happen if some
> other GET/POST values is something.
> 7. Check that two fields contain same value
> 8. If one check box is checked the value of other field should be say
> between 1 and 10 and if not checked it can be between 1 and 100, for
> example.
> 9. Support multivalued fields (e.g. ?foo=1&foo=apple&foo=foo)
>
> I can do this just fine right now:
> local ok, err = validation.tonumber().between(1, 100).outside(40,
> 50)(cgi.get['foo'])
>
> And of course this can be reused:
> local is_some_important_number = validation.tonumber().between(1,
> 100).outside(40, 50)
> local ok, err = is_some_important_number(cgi.get['foo'])
>
> But it is pretty hard to combine all the functionality (e.g. those mentioned
> above) neatly in these kind of oneliners. But I'm quite close, it just needs
> some rethinking (maybe I need to split some functionality or just use a few
> if clauses on more difficult input data).

You could use tables instead of dot/colon chaining and be able to add
subchains with local-break (abort subchain), global-break (abort all
chains), and conditional meta-filters.

/s/ Adam