[ic] [interchange] Add better messages, support for application/json handling

[Peter]

On 12/31/2014 11:50 AM, David Christensen wrote:
>  use strict;
>  
>  {
> -    local $@;
> -    eval {
> -        require JSON;
> -    };
> -    unless ($@) {
> -        $Has_JSON = 1;
> -    }
> +	local $@;
> +	eval {
> +		require JSON;
> +	};
> +	if ($@) {
> +		::logGlobal(
> +			$@ =~ /^Can't locate JSON/ ?
> +			'No POST support for application/json without installing JSON module' :
> +			"Error loading JSON module: $@"
> +		);
> +	}
> +	else {
> +		$Has_JSON = 1;
> +	}
>  }

One correction and a few suggestions...

$Has_JSON will puke because it's undeclared and we use strict.  You want:
our $Has_JSON = 1;

You don't have to test for $@ if you put the our $Has_JSON = 1 in the
eval block like so:

our $Has_JSON;
eval {
    require JSON;
    $Has_JSON = 1;
};

if (!$Has_JSON) {
    # ... error here (see below)?
}


The other thing is that if someone doesn't have JSON it's not really an
error and shouldn't be reported as such, unless they try to enable
UnpackJSON.  I suggest that UnpackJSON should be *off* by default (to
maintain the status quo) and if it's attempted to be turned on with the
JSON module present *then* you record an error (and even crash the
catalog loading at that point).


Peter