(#) Missing Parcelable `CREATOR` field
!!! ERROR: Missing Parcelable `CREATOR` field
This is an error.
Id
: `ParcelCreator`
Summary
: Missing Parcelable `CREATOR` field
Severity
: Error
Category
: Correctness
Platform
: Android
Vendor
: Android Open Source Project
Feedback
: https://issuetracker.google.com/issues/new?component=192708
Since
: Initial
Affects
: Kotlin and Java files
Editing
: This check runs on the fly in the IDE editor
See
: https://developer.android.com/reference/android/os/Parcelable.html
Implementation
: [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/ParcelDetector.java)
Tests
: [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/ParcelDetectorTest.java)
Copyright Year
: 2013
According to the `Parcelable` interface documentation, "Classes
implementing the Parcelable interface must also have a static field
called `CREATOR`, which is an object implementing the
`Parcelable.Creator` interface."
!!! Tip
This lint check has an associated quickfix available in the IDE.
(##) Example
Here is an example of lint warnings produced by this check:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text
src/test/bytecode/MyParcelable1.java:6:Error: This class implements
Parcelable but does not provide a CREATOR field [ParcelCreator]
public class MyParcelable1 implements Parcelable {
-------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Here are the relevant source files:
`src/test/bytecode/MyParcelable1.java`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers
package test.bytecode;
import android.os.Parcel;
import android.os.Parcelable;
public class MyParcelable1 implements Parcelable {
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel arg0, int arg1) {
}
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`src/test/bytecode/MyParcelable2.java`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers
package test.bytecode;
import android.os.Parcel;
import android.os.Parcelable;
public class MyParcelable2 implements Parcelable {
public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {
public MyParcelable2 createFromParcel(Parcel in) {
return new MyParcelable2();
}
public MyParcelable2[] newArray(int size) {
return new MyParcelable2[size];
}
};
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel arg0, int arg1) {
}
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`src/test/bytecode/MyParcelable3.java`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers
package test.bytecode;
import android.os.Parcel;
import android.os.Parcelable;
public class MyParcelable3 implements Parcelable {
public static final int CREATOR = 0; // Wrong type
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel arg0, int arg1) {
}
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`src/test/bytecode/MyParcelable4.java`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers
package test.bytecode;
import android.os.Parcel;
import android.os.Parcelable;
public abstract class MyParcelable4 implements Parcelable {
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel arg0, int arg1) {
}
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`src/test/bytecode/MyParcelable5.java`:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers
package test.bytecode;
import android.os.Parcelable;
public interface MyParcelable5 extends Parcelable {
@Override
public int describeContents();
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You can also visit the
[source code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/ParcelDetectorTest.java)
for the unit tests for this check to see additional scenarios.
The above example was automatically extracted from the first unit test
found for this lint check, `ParcelDetector.testParcelables`.
To report a problem with this extracted sample, visit
https://issuetracker.google.com/issues/new?component=192708.
(##) Suppressing
You can suppress false positives using one of the following mechanisms:
* Using a suppression annotation like this on the enclosing
element:
```kt
// Kotlin
@Suppress("ParcelCreator")
fun method() {
problematicStatement()
}
```
or
```java
// Java
@SuppressWarnings("ParcelCreator")
void method() {
problematicStatement();
}
```
* Using a suppression comment like this on the line above:
```kt
//noinspection ParcelCreator
problematicStatement()
```
* Using a special `lint.xml` file in the source tree which turns off
the check in that folder and any sub folder. A simple file might look
like this:
```xml
<?xml version="1.0" encoding="UTF-8"?>
<lint>
<issue id="ParcelCreator" severity="ignore" />
</lint>
```
Instead of `ignore` you can also change the severity here, for
example from `error` to `warning`. You can find additional
documentation on how to filter issues by path, regular expression and
so on
[here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html).
* In Gradle projects, using the DSL syntax to configure lint. For
example, you can use something like
```gradle
lintOptions {
disable 'ParcelCreator'
}
```
In Android projects this should be nested inside an `android { }`
block.
* For manual invocations of `lint`, using the `--ignore` flag:
```
$ lint --ignore ParcelCreator ...`
```
* Last, but not least, using baselines, as discussed
[here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).