Source
public enum Source
Configures the behavior of get() calls on DocumentReference and Query. By providing a Source value, these methods can be configured to fetch results only from the server, only from the local cache, or attempt to fetch results from the server and fall back to the cache (which is the default).
Summary
Enum Values |
|
|---|---|
CACHE |
Causes Cloud Firestore to immediately return a value from the cache, ignoring the server completely (implying that the returned value may be stale with respect to the value on the server). |
DEFAULT |
Causes Cloud Firestore to try to retrieve an up-to-date (server-retrieved) snapshot, but fall back to returning cached data if the server can't be reached. |
SERVER |
Causes Cloud Firestore to avoid the cache, generating an error if the server cannot be reached. |
Public methods |
|
|---|---|
static Source |
Returns the enum constant of this type with the specified name. |
static Source[] |
values()Returns an array containing the constants of this enum type, in the order they're declared. |
Enum Values
CACHE
Source Source.CACHE
Causes Cloud Firestore to immediately return a value from the cache, ignoring the server completely (implying that the returned value may be stale with respect to the value on the server). If there is no data in the cache to satisfy the get() call, get will return an error and get will return an empty QuerySnapshot with no documents.
DEFAULT
Source Source.DEFAULT
Causes Cloud Firestore to try to retrieve an up-to-date (server-retrieved) snapshot, but fall back to returning cached data if the server can't be reached.
SERVER
Source Source.SERVER
Causes Cloud Firestore to avoid the cache, generating an error if the server cannot be reached. Note that the cache will still be updated if the server request succeeds. Also note that latency-compensation still takes effect, so any pending write operations will be visible in the returned data (merged into the server-provided data).
Public methods
valueOf
public static Source valueOf(String name)
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
| Returns | |
|---|---|
Source |
the enum constant with the specified name |
| Throws | |
|---|---|
java.lang.IllegalArgumentException java.lang.IllegalArgumentException |
if this enum type has no constant with the specified name |
values
public static Source[] values()
Returns an array containing the constants of this enum type, in the order they're declared. This method may be used to iterate over the constants.
| Returns | |
|---|---|
Source[] |
an array containing the constants of this enum type, in the order they're declared |