vaadin / vaadin/framework

ComboBox should not fetch initial data.

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#10,276 6 comments 2 reactions 0 assignees View on GitHub

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enhancement
Dominant language
Java
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Merged PRs (30d)
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Description

The ComboBox should not fetch/send initial data for the dropdown list.

Imagine the following scenario: The ComboBox are powered by data providers which are fetching the items from a database and the application has a lot of comboboxes in one form. That means that not only will be data send in the order of 40*itemsize*comboboxcount (because the default initial data size is 40), but also the providers will need to provide that data, with potentially costly database operations, slowing everything down. Ideally, the ComboBox would only fetch the first time as is required, for example when the user starts typing or the dropdown is opened.

Additionally, the size of the initial fetch that is performed is 40, even though the first page of the combobox only displays ~10 items.

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Research direction

No files or tests are identified in the issue. Start by tracing the ComboBox data-provider path and reproduce a form with many ComboBoxes; done means initial data is not fetched until typing or opening the dropdown, with the initial page sized closer to the roughly 10 visible items.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
frontend
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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