SolarNetwork Core

Class: StreamDatum

domain~ StreamDatum

A stream datum entity.

A stream datum is a datum without any metadata describing the datum property names. The instantantaneous, accumulating, and status property values are stored as the array fields iProps, aProps, and sProps. A DatumStreamMetadata object is required to associate names with these arrays.

new StreamDatum(streamId, ts [, iProps] [, aProps] [, sProps] [, tags])

Constructor.

Parameters:
Name Type Argument Description
streamId string

the datum stream ID
ts Date | number | string

the datum timestamp, either as a Date instance or a form suitable for constructing as new Date(ts)
iProps Array.<Number> <optional>

the instantaneous property values
aProps Array.<Number> <optional>

the accumulating property values
sProps Array.<String> <optional>

the status property values
tags Set.<String> | Array.<String> <optional>

the tag values

Methods

<static> fromJsonEncoding(json, meta)

Parse a JSON string into a StreamDatum instance.

The JSON must be encoded the same way StreamDatum#toJsonEncoding() does.

Parameters:
Name Type Description
json string

the JSON to parse
meta module:domain~DatumStreamMetadata | module:util~DatumStreamMetadataRegistry

a metadata instance or metadata registry to decode with
Returns:

the stream datum instance

Type
module:domain~StreamDatum

<static> fromJsonObject(data, meta)

Create a new StreamDatum instance from an array parsed from a stream datum JSON string.

The array must have been parsed from JSON that was encoded the same way StreamDatum#toJsonEncoding() does.

Parameters:
Name Type Description
data Array

the array parsed from JSON
meta module:domain~DatumStreamMetadata | module:util~DatumStreamMetadataRegistry

a metadata instance or metadata registry to decode with
Returns:

the stream datum instance

Type
module:domain~StreamDatum

propertyValuesForType(samplesType)

Get the property values for a given samples type.

Parameters:
Name Type Description
samplesType module:domain~DatumSamplesType

the type of property values to return
Returns:

the property values for the given type, or undefined if none available

Type
Array

toJsonEncoding( [registry])

Get this object as a standard JSON encoded string value.

This method returns the JSON form of the result of StreamDatum#toJsonObject().

Parameters:
Name Type Argument Description
registry module:util~DatumStreamMetadataRegistry <optional>

a stream metadata registry to encode as a registry-indexed stream datum
Returns:

the JSON encoded string

Type
string

toJsonObject( [registry])

Get this object as an array suitable for encoding into a standard stream datum JSON string.

This method can encode the datum into an array using one of two ways, depending on whether the registry argument is provided. When provided, the first array element will be the stream metadata index based on calling DatumStreamMetadataRegistry#indexOfMetadataStreamId(). Otherwise the first array element will be the stream ID itself.

For example if a registry is used, the resulting array might look like this:

[0, 1650667326308, 12326, null, 230.19719, 50.19501, 6472722]

while without a registry the array might look like this:

["7714f762-2361-4ec2-98ab-7e96807b32a6", 1650667326308, 12326, null, 230.19719, 50.19501, 6472722]
Parameters:
Name Type Argument Description
registry module:util~DatumStreamMetadataRegistry <optional>

a stream metadata registry to encode as a registry-indexed stream datum
Returns:

the datum stream array object

Type
Array

toObject(meta)

Get this instance as a simple object.

The following basic properties will be set on the returned object:

  • streamId - the stream ID
  • date - the timestamp
  • sourceId - the metadata source ID
  • nodeId or locationId - either the node ID or location ID from the metadata
  • tags - any tags (as an Array)

Beyond that, all instantaneous, accumulating, and status properties will be included. If duplicate property names exist between the different classifications, the first-available value will be used.

Parameters:
Name Type Description
meta module:domain~DatumStreamMetadata

a metadata instance to encode the property names with
Returns:

an object populated with all available properties

Type
Object