What is the correct way to pass an Enum as an argument to a Fragment using Navigation Component safeargs

Question

The documentation discusses how to send simple integers and strings. For example:

<argument
    android:name="myIntArg"
    android:defaultValue="255"
    app:argType="integer" />

In the origin Fragment:

val action = OriginFragmentDirections.myAction(myInt)
findNavController().navigate(action)

In the destination Fragment:

val receivedInt = DestinationFragmentArgs.fromBundle(arguments).myIntArg

But say instead of myIntArg, I wanted to send an enum (myEnumArg). How would I do that? What app:argType would I use in my argument?

ianhanniballake · Accepted Answer · 2018-12-07T00:20:59.037

25

Edit: As per the Navigation 1.0.0-alpha08 release notes:

Safe Args supports Serializable objects, including Enum values. Enum types can set a default value by using the enum literal without the class name (e.g. app:defaultValue="READ") b/111316353

So this is now possible - you would use the name of your Enum class (i.e., com.example.EnumClass) or a relative name (.EnumClass) which will automatically prepend your app's package name to the class name.

Previous answer:

This is not possible with the current version of Navigation (1.0.0-alpha07), but the existing feature request is marked as fixed and the ability to use enums as arguments will be available in alpha08

edited Dec 07 '18 at 00:20

answered Nov 29 '18 at 18:39

ianhanniballake

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Ah that's too bad. Any word on when alpha08 will be coming out? – JHowzer Nov 29 '18 at 18:50
1

Seems like it'll be [pretty soon](https://twitter.com/ianhlake/status/1068189435651534848) – ianhanniballake Nov 29 '18 at 18:52
Appreciate the info – JHowzer Nov 29 '18 at 18:54
2

Updated the answer now that Navigation 1.0.0-alpha08 is released with support for Enum classes. – ianhanniballake Dec 06 '18 at 23:16

score 23 · Answer 2 · answered Apr 11 '20 at 13:53

As @ianhanniballake mentioned in his updated answer, you need to use the latest version of Navigation.

Assume we have an Enum like below and your app package name is com.example.app.

package com.example.app.path.to.type.file

public enum class Type {
    First,
    Second,
    Third
}

Now we just need to declare the Arg like this:

<fragment
    ...>
    <argument
        android:name="type"
        android:defaultValue="Second"
        app:argType=".path.to.type.file.Type" />
...
</fragment>

How would you use this with compose navigation? – lenooh Mar 14 '22 at 14:02 — lenooh, Mar 14 '22 at 14:02

score 1 · Answer 3 · answered May 29 '23 at 02:57

For those wondering how this would be done with Compose, according to NavType.EnumType you just use NavType.EnumType:

composable(
     YOUR_ROUTE,
     arguments = listOf(navArgument(ARGUMENT_NAME) {
                    type = NavType.EnumType(YOUR_ENUM::class.java)
                 }
     )
)

What is the correct way to pass an Enum as an argument to a Fragment using Navigation Component safeargs

3 Answers3