CODEWITHSUNDEEP
google-app-maker
Mauricio
Mauricio

Reputation: 29

How to sort a table for which its datasource is a relation

I have a Page with a Table for which its datasource is a relation and needs to be sorted based on fields from another model:

Page
     Datasource = Indicators
Table
     Datasource = Indicators [one] : MetadataText [many] (relation)

The Table needs to be sorted based on a field from another Model called MetadataField, which has a one to many relation with MetadataText.

I have the datasource of MetadataField sorted. But the content in the Table appears in random order. When I first access the application, the Table is sorted by the order that the records were loaded. After view some records, the sorting of the records changes and keeps changing.

I am using Google Drive tables.

Upvotes: 1

Views: 475

Answers (1)

Pavel Shkleinik
Pavel Shkleinik

Reputation: 6347

You can easily sort related records by one of the fields that belong to the related record itself, but only once (you'll received those records sorted from server).

select relation sorting

But it seems, that you want to sort related records by their related record. App Maker will not be your friend in this case... but javascript will be! Since App Maker loads all related records you can safely sort them on client using javascript:

indicatorsDatasource.load(function() {
  indicatorsDatasource.items.forEach(function(indicator) {
    indicator.MetadataTexts.sort(function(a, b) {
       return /* here goes your sorting logic */;
    });
  });
});

It will work in O(n * m * log(m)) in case you have n Indicators on the page and every indicator has m associated MetadataTexts. If you want to let users to sort related records by clicking table's header, you'll need to implement that logic on your own. So... all this hassle leads us to alternative solution! What if we decouple related records and introduce separated datasource for them? Having that you'll be able to use full power of App Maker's tables (sorting/paging) with almost no effort. You can take a look at implementation sample in Project Tracker template ViewProject page.

Upvotes: 1

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