JSONPath syntax for value retrieval
- Last UpdatedSep 30, 2024
- 3 minute read
For information on which semantic is used for retrieving values from JSON files, see JSONPath Syntax.
The following syntax is used to extract values from JSON documents.
JSON - Simple JSONPath example
[
{
"time": "2020-08-10T12:10:46.0928791Z",
"value": 1.234567890
},
{
"time": "2020-08-10T12:10:47.0928791Z",
"value": 12.34567890
},
{
"time": "2020-08-10T12:10:48.0928791Z",
"value": 123.4567890
},
{
"time": "2020-08-10T12:10:49.0928791Z",
"value": 1234.567890
},
{
"time": "2020-08-10T12:10:50.0928791Z",
"value": 12345.67890
},
{
"time": "2020-08-10T12:10:51.0928791Z",
"value": 123456.7890
},
{
"time": "2020-08-10T12:10:52.0928791Z",
"value": 12345678.90
},
{
"time": "2020-08-10T12:10:53.0928791Z",
"value": 123456789.0
}
]
The following JSONPath configuration reads a series of values:
{
"Id": "DoubleValue",
"FieldDefinition": "value",
"DataType": "Double"
},
{
"Id": "Timestamp",
"FieldDefinition": "time",
"DataType": "DateTime",
"IsIndex": true
}
JSON - Complex JSONPath examples
The following example reads specific values from a JSON array:
{
"StreamData": {
"TPPrototype.uflsample.value_time": [
{
"StreamId": "TPPrototype.uflsample.value_time",
"DataType": "Double",
"Timestamp": "2013-12-01T06:00:00Z",
"Value": 339.0
},
{
"StreamId": "TPPrototype.uflsample.value_time",
"DataType": "Double",
"Timestamp": "2013-12-01T07:00:00Z",
"Value": 344.0
},
{
"StreamId": "TPPrototype.uflsample.value_time",
"DataType": "Double",
"Timestamp": "2013-12-01T17:00:00Z",
"Value": 341.0
}
],
"TPPrototype.uflsample.value_timeString": [
{
"StreamId": "TPPrototype.uflsample.value_timeString",
"DataType": "String",
"Timestamp": "2013-12-01T06:00:00Z",
"Value": "339.0"
},
{
"StreamId": "TPPrototype.uflsample.value_timeString",
"DataType": "String",
"Timestamp": "2013-12-01T07:00:00Z",
"Value": "344.0"
},
{
"StreamId": "TPPrototype.uflsample.value_timeString",
"DataType": "String",
"Timestamp": "2013-12-01T17:00:00Z",
"Value": "341.0"
}
],
"TPPrototype.uflsample.pressure_time": [
{
"StreamId": "TPPrototype.uflsample.pressure_time",
"DataType": "Double",
"Timestamp": "2013-12-01T06:00:00Z",
"Value": 339.0
},
{
"StreamId": "TPPrototype.uflsample.pressure_time",
"DataType": "Double",
"Timestamp": "2013-12-01T07:00:00Z",
"Value": 344.0
},
{
"StreamId": "TPPrototype.uflsample.pressure_time",
"DataType": "Double",
"Timestamp": "2013-12-01T17:00:00Z",
"Value": 341.0
}
]
}
}
The following JSONPath configuration reads all the TPPrototype.uflsample.value_time values from the JSON above:
{
"Id": "Value",
"DataType": "Double",
"FieldDefinition": "$['StreamData'].['TPPrototype.uflsample.value_time'][*].Value"
},
{
"Id": "Time",
"DataType": "DateTime",
"FieldDefinition": "$['StreamData'].['TPPrototype.uflsample.value_time'][*].Timestamp",
"IsIndex": true
}
The following example reads specific value from complex nested JSON:
{
"success": true,
"error": null,
"result": {
"type": "runtime_history",
"chart": {
"chart": {
"type": "column"
},
"title": {
"text": ""
},
"subtitle": {
"text": "Daily History"
},
"colors": [
"#fee292",
"#fdc152",
"#f69638",
"#f17130",
"#9f2d26",
"#8acadc",
"#184c8e"
],
"series": [
{
"name": "Stage 3 Aux Heat",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": "heat",
"state": "heat_aux_stage3"
},
{
"name": "Stage 2 Aux Heat",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": "heat",
"state": "heat_aux_stage2"
},
{
"name": "Aux Heat",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": "heat",
"state": "heat_aux"
},
{
"name": "Stage 2 Heat",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": "heat",
"state": "heat_stage2"
},
{
"name": "Heat",
"data": [
0.0,
0.2,
0.0,
0.0,
0.0,
0.0,
0.3,
0.2,
0.0
],
"stack": "heat",
"state": "heat"
},
{
"name": "Stage 2 Cool",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": "cool",
"state": "cool_stage2"
},
{
"name": "Cool",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": "cool",
"state": "cool"
}
],
"xAxis": {
"categories": [
"Friday",
"Saturday",
"Sunday",
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday",
"Saturday"
],
"labels": {
"rotation": -45
}
},
"yAxis": {
"allowDecimals": false,
"min": 0,
"max": 24,
"tickInternval": 4,
"title": {
"text": "Runtime (Hours)"
}
},
"legend": {
"layout": "vertical",
"align": "center",
"floating": false,
"shadow": false,
"itemStyle": {
"fontSize": "1em"
}
},
"tooltip": {
"shared": true,
"borderColor": "#000000"
},
"credits": {
"enabled": false
},
"plotOptions": {
"column": {
"stacking": "normal"
},
"series": {
"shadow": false
}
}
},
"table": {
"headings": [
"Fri",
"Sat",
"Sun",
"Mon",
"Tue",
"Wed",
"Thu",
"Fri",
"Sat"
],
"series": [
{
"name": "Aux Heat",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": "heat",
"state": "heat_aux"
},
{
"name": "Outdoor High Temp.",
"data": [
72.0,
64.0,
73.0,
72.0,
67.0,
73.0,
77.0,
62.0,
51.0
],
"stack": null,
"state": "outdoor_high_temperature"
},
{
"name": "Outdoor Low Temp.",
"data": [
55.0,
60.0,
62.0,
61.0,
51.0,
43.0,
46.0,
44.0,
35.0
],
"stack": null,
"state": "outdoor_low_temperature"
},
{
"name": "Avg Indoor Temp.",
"data": [
76.0,
77.0,
78.0,
78.0,
77.0,
73.0,
74.0,
75.0,
72.0
],
"stack": null,
"state": "average_indoor_temperature"
},
{
"name": "Avg Indoor Humidity",
"data": [
66.0,
68.0,
70.0,
70.0,
69.0,
67.0,
67.0,
66.0,
61.0
],
"stack": null,
"state": "average_indoor_humidity"
},
{
"name": "Fan Only Runtime",
"data": [
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"stack": null,
"state": "fan_only"
},
{
"name": "Vent",
"data": [],
"stack": null,
"state": "vent"
}
]
},
"show_monthly_runtime_history": true
}
}
The following JSONPath configuration reads Sunday Average Indoor Temperature. The timestamp comes from Adapter local time.
{
"Id": "Temperature",
"DataType": "Double",
"FieldDefinition": "$.result.table.series[3].data[2]"
},
{
"Id": "Timestamp",
"DataType": "DateTime",
"Format": "Adapter",
"IsIndex": true
}
Error handling
If you encounter text parser related errors that is errors for the ValueField or IndexField, check the StreamId associated with the error message.
Possible errors include the following:
-
The JSONPath expression of ValueField or IndexField is pointing to a non-existing value
-
The JSONPath expression of ValueField or IndexField is missing a value altogether
-
DataType does not match the value