- Since:
- 3.0
- See:
Members
(static, readonly) None :ServerlessDb.Constraint
No constraint: the values of data nodes are sent without filtering any child node.
Type:
Methods
(static) Between(startKey, endKey) → {ServerlessDb.Constraint}
Children between: the values of data nodes sent by subscriptions will be limited to the child nodes of the
actual data nodes whose keys are between startKey and endKey (included).
Child nodes are ordered with respect to their keys in a
dedicated lexicographic order. For example, if the actual data
node to send is {a:9, b:8, c:7}, the Between("a", "abc") constraint will send {a:9} to notification
targets.
Parameters:
| Name | Type | Description |
|---|---|---|
startKey |
string | Key that is lower than or equals (following the lexicographic order) the key of the first child that can be sent by subscriptions. |
endKey |
string | Key that is greater than or equals (following the lexicographic order) the key of the last child that can be sent by subscriptions. |
Returns:
(static) EndAt(endKey, limitopt) → {ServerlessDb.Constraint}
limit children until endKey: the values of data nodes sent by subscriptions will be limited to the last
limit child nodes (or all child nodes if limit is not set) of the actual data nodes whose keys are lesser
than or equal endKey.
Child nodes are ordered with respect to their keys in a
dedicated lexicographic order. For example, if the actual data
node to send is {a:9, b:8, c:7}, the EndAt("cba", 2) constraint will send {b:8, c:7} to notification
targets.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
endKey |
string | Key that is greater than or equals (following the lexicographic order) the key of the last child that can be sent by subscriptions. |
|
limit |
number |
<optional> |
Returns:
(static) First(limit) → {ServerlessDb.Constraint}
First limit children: the values of data nodes sent by subscriptions will be limited to the first limit
child nodes of the actual data nodes.
Child nodes are ordered with respect to their keys in a
dedicated lexicographic order. For example, if the actual data
node to send is {a:9, b:8, c:7}, the First(2) constraint will send {a:9, b:8} to notification targets.
Parameters:
| Name | Type | Description |
|---|---|---|
limit |
number | Maximum number of children that can be sent by subscriptions, starting from the first one in lexicographic order. |
Returns:
(static) Last(limit) → {ServerlessDb.Constraint}
Last limit children: the values of data nodes sent by subscriptions will be limited to the last limit
child nodes of the actual data nodes.
Child nodes are ordered with respect to their keys in a
dedicated lexicographic order. For example, if the actual data
node to send is {a:9, b:8, c:7}, the Last(2) constraint will send {b:8,c:7} to notification targets.
Parameters:
| Name | Type | Description |
|---|---|---|
limit |
number | Maximum number of children that can be sent by subscriptions, starting from the last one in lexicographic order. |
Returns:
(static) StartAt(startKey, limitopt) → {ServerlessDb.Constraint}
limit children from startKey: the values of data nodes sent by subscriptions will be limited to the first
limit child nodes (or all child nodes if limit is not set) of the actual data nodes whose keys are greater
than or equal startKey.
Child nodes are ordered with respect to their keys in a
dedicated lexicographic order. For example, if the actual data
node to send is {a:9, b:8, c:7}, the StartAt("abc", 1) constraint will send {a:9} to notification targets.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
startKey |
string | Key that is lower than or equals (following the lexicographic order) the key of the first child that can be sent by subscriptions. |
|
limit |
number |
<optional> |
If set, maximum number of children that can be sent by subscriptions from the given
|