tm_team_transfers() returns wrong leagues for past seasons

[drasbaek]

The tm_team_transfers(team_url, transfer_window = "all") function returns the team's current league rather than the one the team played in, in the given season.

For example:

# get transfers from Luton Town in 2018 (played in League One)
tm_team_transfers("https://www.transfermarkt.com/luton-town/startseite/verein/1031/saison_id/2018", transfer_window = "all")

Gives the correct transfers for the season but not the correct league for each row (Is Premier League, should be League One)

| #   | Team Name   | League          | Country | Season | Transfer Type | Player Name        | Player URL                                      | Player Position    | Player Age |
| --- | ----------- | --------------- | ------- | ------ | ------------- | ------------------ | ---------------------------------------------- | ------------------ | ---------- |
| 1   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Andrew Shinnie     |https://www.transfermarkt.com/andrew-shinnie/profil/spieler/51733 | Attacking Midfield | 28         |
| 2   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Sonny Bradley      |https://www.transfermarkt.com/sonny-bradley/profil/spieler/127794 | Centre-Back        | 26         |
| 3   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Matty Pearson      |https://www.transfermarkt.com/matty-pearson/profil/spieler/121395 | Centre-Back        | 24         |
| 4   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Eunan O'Kane       |https://www.transfermarkt.com/eunan-okane/profil/spieler/61583   | Central Midfield  | 28         |
| 5   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Jorge Grant        |https://www.transfermarkt.com/jorge-grant/profil/spieler/334964 | Central Midfield  | 23         |
| 6   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Kazenga LuaLua     |https://www.transfermarkt.com/kazenga-lualua/profil/spieler/52576 | Left Winger       | 27         |
| 7   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Jack James         |https://www.transfermarkt.com/jack-james/profil/spieler/531863  | Right-Back        | 18         |
| 8   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Luke Gambin        |https://www.transfermarkt.com/luke-gambin/profil/spieler/225121| Left Winger       | 26         |
| 9   | Luton Town  | Premier League  | England | 2018   | Arrivals      | Jake Jervis        |https://www.transfermarkt.com/jake-jervis/profil/spieler/129074  | Right Winger      | 27         |
| 10  | Luton Town  | Premier League  | England | 2018   | Arrivals      | Lloyd Jones        |https://www.transfermarkt.com/lloyd-jones/profil/spieler/244040 | Centre-Back       | 23         |
| ... | ...         | ...             | ...     | ...    | ...           | ...                | ...                                            | ...               | ...        |

Session info:

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] worldfootballR_0.6.4.0008

loaded via a namespace (and not attached):
 [1] pillar_1.9.0      compiler_4.2.2    prettyunits_1.1.1 tools_4.2.2       progress_1.2.2    digest_0.6.29     lubridate_1.9.2   jsonlite_1.8.4    evaluate_0.16    
[10] lifecycle_1.0.3   tibble_3.2.1      timechange_0.2.0  pkgconfig_2.0.3   rlang_1.1.0       cli_3.6.1         rstudioapi_0.15.0 yaml_2.3.5        xfun_0.32        
[19] fastmap_1.1.0     dplyr_1.1.1       httr_1.4.6        stringr_1.5.0     knitr_1.39        xml2_1.3.3        generics_0.1.3    vctrs_0.6.1       hms_1.1.3        
[28] tidyselect_1.2.0  glue_1.6.2        R6_2.5.1          fansi_1.0.4       rmarkdown_2.18    tidyr_1.3.0       purrr_1.0.1       readr_2.1.4       tzdb_0.3.0       
[37] magrittr_2.0.3    htmltools_0.5.3   rvest_1.0.3       utf8_1.2.3        stringi_1.7.8     crayon_1.5.2     

[JaseZiv]

Yeah this one is problematic... There's no real way around this other than introducing extra page loads to get the relevant league for that particular season... currently, the league is extracted from the relevant season's transfer page, but this league value is for the current league

Given transfermarkt page loads (and then scraping) is already pretty slow, I'm not overly keen on introducing additional page loads.

Will leave this open for now until a neater solution presents itself.