Tracker: Delay log of page view/visit to include onload metric

[rr-it]

Description:

This PR delays logging of every page view/visit to whatever comes first:

• after load event is fired
• visitor leaves page

The PagePerformance metric time_on_load is only availible via JavaScript API PerformanceTiming.loadEventEnd in the browser after the load event handler has finished.

Related to #20726

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed

[rr-it]

For me this works as expected in production now. Especially when the Matomo tracking code is executed before onload.

Without this change implemented (day A):
Some data for dom_completion and on_load is missing.

views	total	network	server	time_transfer	processing	dom_completion	on_load
with peformance data	3925	3925	3925	3925	3739	> 1577 <	> 1577 <
without peformance data	1688	0	0	0	0	0	0

SQL to reproduce statistics (click to open)

Hint: COUNT() does not take values of NULL into account.

SELECT
'with peformance data' as views,
COUNT(`idlink_va`) as total,
COUNT(`time_network`) as network,
COUNT(`time_server`) as server,
COUNT(`time_transfer`) as time_transfer,
COUNT(`time_dom_processing`) as processing,
COUNT(`time_dom_completion`) as dom_completion,
COUNT(`time_on_load`) as on_load
FROM `matomo_log_link_visit_action`
WHERE `idsite` = 1
AND `time_server` > 0 AND `time_server` IS NOT NULL
AND server_time > '2023-05-28 12:30:00' AND server_time < '2023-05-29 12:30:00'

UNION

SELECT
'without peformance data' as views,
COUNT(`idlink_va`) as total,
COUNT(`time_network`) as network,
0 as server,
COUNT(`time_transfer`) as time_transfer,
COUNT(`time_dom_processing`) as processing,
COUNT(`time_dom_completion`) as dom_completion,
COUNT(`time_on_load`) as on_load
FROM `matomo_log_link_visit_action`
WHERE `idsite` = 1
AND `time_server` IS NULL
AND server_time > '2023-05-28 12:30:00' AND server_time < '2023-05-29 12:30:00'

With this change implemented (day B):
Nearly every record with performance data has also tracked dom_completion and on_load.

views	total	network	server	time_transfer	processing	dom_completion	on_load
with peformance data	3977	3977	3977	3976	3976	> 3898 <	> 3895 <
without peformance data	1715	0	0	0	0	0	0

SQL to reproduce statistics (click to open)

Hint: COUNT() does not take values of NULL into account.

SELECT
'with peformance data' as views,
COUNT(`idlink_va`) as total,
COUNT(`time_network`) as network,
COUNT(`time_server`) as server,
COUNT(`time_transfer`) as time_transfer,
COUNT(`time_dom_processing`) as processing,
COUNT(`time_dom_completion`) as dom_completion,
COUNT(`time_on_load`) as on_load
FROM `matomo_log_link_visit_action`
WHERE `idsite` = 1
AND `time_server` > 0 AND `time_server` IS NOT NULL
AND server_time > '2023-05-29 12:45:00'

UNION

SELECT
'without peformance data' as views,
COUNT(`idlink_va`) as total,
COUNT(`time_network`) as network,
0 as server,
COUNT(`time_transfer`) as time_transfer,
COUNT(`time_dom_processing`) as processing,
COUNT(`time_dom_completion`) as dom_completion,
COUNT(`time_on_load`) as on_load
FROM `matomo_log_link_visit_action`
WHERE `idsite` = 1
AND `time_server` IS NULL
AND server_time > '2023-05-29 12:45:00'

[github-actions]

If you don't want this PR to be closed automatically in 28 days then you need to assign the label 'Do not close'.

[github-actions]

This PR was last updated more than one month ago, maybe it's time to close it. Please check if there is anything we still can do or close this PR. ping @matomo-org/core-reviewers

[github-actions]

If you don't want this PR to be closed automatically in 28 days then you need to assign the label 'Do not close'.

[github-actions]

This PR was last updated more than one month ago, maybe it's time to close it. Please check if there is anything we still can do or close this PR. ping @matomo-org/core-reviewers

[rr-it]

Also resolves #22339

[rr-it]

This might need an additional feature:
If performance-data sending is delayed, then send the performance-data at the latest before a second trackPageView is tracked.

[github-actions]

This PR was last updated more than one month ago, maybe it's time to close it. Please check if there is anything we still can do or close this PR. ping @matomo-org/core-reviewers