Group all Google search SSL unknown keywords under "Keyword not defined"

[matt]

See Piwik Keyword not defined FAQ

See  google announcement

We should make sure that the "search engine" appears as google still, but keyword would appear as "Keyword not provided"

[matt]

Apparently it is not standard SSL behavior, they somehow still pass the referrer but with empty &q= query parameter.

[matt]

In the log_visit DB, I suggest that the referer_name be "google" and referer_keyword be empty string. During archiving, the datatable label would be a constant KEYWORD_NOT_PROVIDED. Then, this will be replaced in an API filter with the localized string eg. "Keyword not provided" in english.

[vipsoft]

For the detection logic:

• no referrer - track as a search engine with empty keyword
• a referrer with specified query parameter but empty is also a search engine with empty keyword
• where the keyword is non-empty, track as search engine with non-empty keyword
• where the keyword detection fails, track as external website

[matt]

Replying to vipsoft:

For the detection logic: - no referrer - track as a search engine with empty keyword

No referrer == Direct entry, not search engine :)

Otherwise OK!

[vipsoft]

What about the case where the referrer is just http://domain.tld

[matt]

(In [5604]) Fixes #2718

• Only fixes for Google for now, we can generalize the code later when other search engines start doing the same
• Marking hidden keywords as "Keyword not defined"
• Linking the keyword to the new FAQ: Piwik Keyword not defined

[matt]

(In [5756]) Refs #2718

• do not display "Your top converting keywords are: 'Keyword not defined'" because it is very irritating!

[matt]

(In [5800]) Refs #2718

• Do not display "Keyword not defined" in the widget showing top keywords per page