When API returns a datatable that has only one column, column name is "value"

[tsteur]

Compare eg output of http://demo.piwik.org/index.php?module=API&method=API.get&idSite=7&period=day&date=yesterday&format=JSON&token_auth=anonymous

{"nb_uniq_visitors":586,"nb_visits":651,"nb_users":0,"nb_actions":1394,"max_actions":48,...}

with output of http://demo.piwik.org/index.php?module=API&method=API.get&idSite=7&period=day&date=yesterday&format=JSON&token_auth=anonymous&columns=nb_visits

{"value":651}

Expected is

{"nb_visits":651}

I wouldn't be surprised if this even causes bugs in the UI etc depending on the selected columns

[diosmosis]

Note: this is due to logic that reduces DataTable w/ one row + one column to single value (ie [{"nb_visits": 0}] turns into 0), so the column name is lost. This logic might be in core/Archive.php as opposed to the DataTable renderer.

[mattab]

it would be BC break so adding to 3.0.0 milestone in case we want to fix it then

[andyjdavis]

I was curious and this bug still exists.

Return many columns.
https://demo.matomo.cloud/index.php?module=API&method=API.get&idSite=1&period=day&date=yesterday&format=JSON&token_auth=anonymous
{"nb_uniq_visitors":2966,"nb_visits":3161,"nb_users":2...

Return a single column.
https://demo.matomo.cloud/index.php?module=API&method=API.get&idSite=1&period=day&date=yesterday&format=JSON&token_auth=anonymous&columns=nb_visits
{"value":3161}

[andyjdavis]

Here is a possible fix for this. #17535

There are currently test failures as I haven't yet updated the expected values in the tests. I'm posting my work thus far in the hopes of verifying that this approach is acceptable.

[andyjdavis]

I have closed that pull request as this is a breaking change that needs to wait for the next major version (5.0.0).

[mattab]

We're thinking we need to postpone this to Matomo 6.0.0 due to lack of time.