Local variable to display temporary list

TakadaGuna

Hello,

I am wondering if there is such thing a local variable in REI3. Here's the case I am facing: I have a quite long list of price updates for many items. So I would like to have a form where I would show a list of latest price of each item. So it would find a latest entry for each item, putting it inside a temporary list, and show that on the form. However, I would not want to save that list because that will be too much data to save (everytime anyone open that page it would basically get new data). I think I would need some kind of local variable to hold the data temporarily, but would get destroyed upon closing the page.

Is there any way to do this ? Thanks in advance.

lsw-fabian

Hi @TakadaGuna,
to achieve this you could use the value store inside frontend functions
app.value_store_set('key', value) --> this will save a value inside the value store app.value_store_get('key');--> get the saved data app.value_store_set('key', undefined) --> clear the value store variable
Hope this will help.

TakadaGuna

Hello fabian,
Thank you for the prompt reply. However, I still have a question. I understand how to use that solution for a single text value. But how can I use it to build a list with several columns (for example "item_name", "price", "update_time") and then show that on the page?

lsw-fabian

TakadaGuna yes, the most common way to use the value store is with a single value.
But you can also store things like an array or an json string inside the store. In your case you could create an array with your values and store it in the value store afterwards

lsw-fabian

on the other hand you could maybe also work with collection - so you still have list and dont have to convert your data into things like an array.

TakadaGuna

Is it possible to achieve what I want simply by using sub query to filter the list (for each item simply filter the records with latest date) ? Is there examples on how to use sub-query to filter a list in the built-in applications?

lsw-fabian

TakadaGuna i think we have a lot of examples in our applications on how to work with subqueries. It depends a lot on your usecase. I need to see & understand your application and your needs to tell you specific what i would do.

TakadaGuna

Hello again,
I found a solution for my case by using a simple list and then filter the list usinh sub-queries. After some trials, I now understand how to use sub queries to filter a list. It’s much simpler than I thought 😁

Anyways, thank you for the help and discussion. I learned some new functions and new ways to manipulate lists. And as always, thank you for this amazing platform. Really appreciate it 🤗