EZP-26630: Support per-query raw filters

[peterkeung]

https://jira.ez.no/browse/EZP-26630

In eZ Find, all filters expect to follow the pattern field:value. If you don't have a colon, ezfeZPSolrQueryBuilder::getParamFilterQuery() prepends a colon, effectively breaking some filters. This prevents you from adding special filters for the "fq" parameter in Solr, such as frange queries:

http://solr.pl/en/2011/05/30/quick-look-frange/

An example use case is to enforce a minimum relevance score:

{!frange l=1}query({!edismax v=$q})

You can get around this by using RawFilterList in ezfind.ini, but that's applied to every query.

This proposed solution would add a new parameter "raw_filter" to the ezfind/search fetch function:

'raw_filter', array( '{!frange l=1\}query({!edismax v=$q\})' ),

[peterkeung]

Ping @moismailzai @benkmugo

[moismailzai]

+1 this looks good to me.

I can confirm this patch is functional and works well in practice (that is, the filter range is limiting results as expected).

[benkmugo]

The flexibility this adds is a good improvement I think. It avoids having to use workarounds or going via the raw solr fetch in template land.

+1

[gggeek]

+1 (apart from remark)

[gggeek]

why not add it as last param? better for BC

[peterkeung]

Sure -- easy change to make. @andrerom who else would we need approval from before merging?

[andrerom]

Well this BC point should probably be fixed and then maybe there is another approval coming :)

[peterkeung]

OK, $rawFilters has been moved to the last param now!

[pkamps]

I don't like that the parameters filter and raw_filter take an array for the value. I think it will combine multiple array elements with a logical AND. That's something not very obvious for a developer.
But that's how the parameter filter was developed and raw_filter is now consistent to that approach - so I'm OK with it.
Maybe we add inline doc saying something about how multiple array entries are handled.

+1

[benkmugo]

I think adding a brief inline doc note about those two parameter values would be a good idea.

[peterkeung]

@pkamps @benkmugo I've added additional comments where the filters are built

[benkmugo]

+1

[peterkeung]

Let's get this merged!