---
title: "Pre-populate values from previous entries based on parent values"
url: "https://openforis.support/questions/3509/pre-populate-values-from-previous-entries-based-on-parent-values"
tags: ["arena", "collect", "collectmobile"]
status: "answered"
score: 0
answer_count: 2
asked: "2022-12-28T22:23:51"
last_activity: "2023-01-10T13:41:32"
source: "Open Foris Support - Q&A Forum"
license: "Copyright Open Foris, 2026. Some rights reserved under creative commons license."
---

# Pre-populate values from previous entries based on parent values

Asked by bryant on 2022-12-28

Hello OF! I would like to use Collect Mobile for a long-term forest monitoring study that requires repeated sampling of plots every 5 years. The survey structure consists of multiple 1:N entities nested under a single "Plot". I would like to pre-populate the "Trees" entity with the list of previously-sampled trees conditional on the value of "Plot". This would be helpful for our technicians because some attributes do not change between years ("Species", for example) while others do change ("DBH") and would need to be updated in the field. Is this type of pre-population possible using Arena/Collect/Collect Mobile? Thank you!


## Answer (score 1, by Stefano (OF) on 2023-01-04)

Link: https://openforis.support/questions/3509/pre-populate-values-from-previous-entries-based-on-parent-values/3511

Dear user,  
What you are trying to achieve will be addressed in a better way in Arena (the new online platform for data collection) and Arena Mobile; they both support "cycles", so you can for example collect data in one cycle, duplicate the data for the next cycle and use it the mobile application during data collection in the field.  
In Collect Mobile there isn't any possibility to import already existing data; what you can try to do is to use the sampling point data to store the information about the already collected tree data in the field; you can have in the first level the plot (matching the plot_id), in the second level the tree (matching the tree_id) and you can have some "extra" information associated to every tree, that would be the already collected data, and use this information in some calculated attributes or expressions.  
I hope this could be helpful, many thanks.  
Open Foris Team


## Answer (score 0, by bryant on 2023-01-09)

Link: https://openforis.support/questions/3509/pre-populate-values-from-previous-entries-based-on-parent-values/3519

Excellent, thank you! I look forward to the release of Arena Mobile. Is it still anticipated to be released in January 2023?

> Hello Bryant, OF Arena Mobile is still under the review & development, and we plan to launch it in March/April '23. -Lauri, OF Team (Lauri (OF))