React Native - Saving search terms after delay - react-native

Question

I am creating a search toolbar that allows the user to see their most recent searches, using Realm Browser as my database. I save a search whenever the user types in the TextInput component, however, I don't want to add a search term after each key stroke, but only after the user has stopped typing for certain amount of time.
handleOnChange function will update state and only call getResults after 2 seconds
handleOnChange(text) {
this.setState({
searchStr: text
}, () => setTimeout(() => {
this.getResults()
}, 2000))
}
In getResults, I call my addRecentSearch function if certain criteria is met.
getResults() {
let searchTags = []
let searchCalcs = []
let tagNames = this.state.tags.map((tag) => {
return tag.name
})
if (this.state.searchStr.length >= 2 || this.state.tags.length !== 0) {
searchCalcs = Realm.searchCalcs(this.state.searchStr, tagNames)
Realm.addRecentSearch(this.state.searchStr)
}
this.setState({
results: searchCalcs,
tagsForFiltering: searchTags
})
}
So I use setTimeout to allow enough time for my state to get updated when the user types. Then, once the states been updated, I will want to add the search query. However, I'm not getting the results I expected when grabbing the most recent searches.
For example:
Type: "h"
Result: nothing happens as str must be at least 2 characters in length
Type: "he"
Result: meets criteria, and will add "he" as a recent search term.
Arr: ["he"]
Type: "heart" (Note: adding 3 characters in succession)
Result: It seems that even with the timeout function, my getResults function is being called (thus adding the search query for each character I added)
Arr: ["he", "heart", "heart", "heart"]
I want my arr to look like:
arr: ["he", "heart"]

Answer 1

You aren't fully debouncing in your example. You are only delaying everything by 2000ms. You need to create a timer and then reset it every time a change happens (by clearing and starting timer again). In this way, only the final 'delay' takes effect. Make sense?
You are very close to have written your own debounce function, so you can use clearTimeout, or there are some libraries that do it. See Lodash https://lodash.com/docs/#debounce