Unity UI - Value of text input (assigned with OnChange event) is always "one letter behind"

Question

I am having a problem in unity setting up a search field. I will post pictures down reggarding my problem but first let me quickly explain what is going on.

I have input element in my ui and i have working search function ready to use. The problem is that the string i feed my search function with is assigned from the inputfield text element value, which appears to be always one step behind.

What i mean is when I type "Wooden door" inputfield value is "Wooden doo".

It is quite annoying and I have no idea what is going on. Please point me into right direction.

Let me post the pictures with quick descriptions.

My UI:

My problem (item I am looking for is named "Wooden door"):

Second image of my problem (door item should not be present):

Finaly my ui settings and code:

Assigning value here:

My search control script:

using UnityEngine;
using UnityEngine.UI;
public class SearchControl : MonoBehaviour
{
public InputField inputField;
public Text searchInput;

private void Start()
{
    inputField = GetComponent<InputField>();
    searchInput = inputField.textComponent;
}

public void Search()
{
    if (searchInput == null)
    {
        Debug.LogWarning("Can't find search field.");
        return;
    }
    //TODO: text value is always one letter behind.
    string searchVal = searchInput.text;
    Debug.Log("Searching value: " + searchVal);

    CraftingManager.instance.RenderSearchedRecipes(searchVal);
}
}

I think there is some kind of character "verification" going on there and the real value of that text field is really one letter behind (since i assign it befor it gets verified). But that is not acceptable and I have no idea what can i do to avoid it. Thank you for any help!

Answer 1

Misleading variable names strike again.

searchInput, despite "input" in its name, isn't pointing to your input field that's receiving the new text. It's the display text object.

The display text field does not find out about the new string until after the change has been handled by your onValueChanged script, because your script might have changed the text that you want the user to see (say, deleting forbidden characters or adding formatting to a phone number)

You want to ask inputField.text for the user's latest input, instead of searchInput.text.

And I'd recommend renaming searchInput to something like searchDisplayText so you or another developer won't confuse it for an input source in future.

Also, note this was exactly the resolution to the existing Q&A thread I linked you to from two years ago, so don't underestimate your ability to find these answers for yourself by searching.

Answer 2

you do not need the extra searchInput you can remove that and switch out to get the text from inputField.text

private void Start()
{
inputField = GetComponent<InputField>();
searchInput = inputField.textComponent;//can remove this line
}
public void Search()
{
  if (searchInput == null)
  {
    Debug.LogWarning("Can't find search field.");
    return;
  }
//TODO: text value is always one letter behind.
string searchVal = inputField.text;//and change this to get value of inputField text instead of textComponent;
Debug.Log("Searching value: " + searchVal);

CraftingManager.instance.RenderSearchedRecipes(searchVal);
}

Answer 3

Another way to achieve this is to make use of dynamic parameters on UnityEvents.

Events that can provide parameters at runtime are marked with those parameters in the inspector (and detailed in the relevant doc pages). e.g. On Value Changed (String) in the inspector shows that this event can provide a string argument - in this case the provided argument is the new value.

An example of writing a handler which could process that:

public void Search(string searchString) {
    CraftingManager.instance.RenderSearchedRecipies(searchString);
}

This negates the need for referencing the input or display components directly, meaning less possibility for confusion. Plus the bonus that it does not need to be part of the same GameObject, if that ever needs to change.

You would assign this handler in the same way as any other - just make sure you select your function from the Dynamic section of the drop-down (otherwise Unity will expect you to provide a parameter in the inspector which will remain the same for each call).