Theia is system for dynamic calculation objects based on Drools Rule Engine
- Objects in JSON format
- Business Rules are rules on DRL (Drools Rule Language) format
- RestApi for communication between Theia and your application
- Easy deploy ensure docker, see file docker-compose.prod.yml
Request JSON has to format like:
{
"Rules":[ ],
"CalculationObjects":[ ]
}| Field | Require | Description |
|---|---|---|
| Rules | yes | Array rule (p. 1.1) |
| CalculationObjects | yes | Array object for calculation (p. 1.2) |
Response JSON has format:
{
"FiredRules": 0,
"CalculationObjects":[ ]
}| Field | Description |
|---|---|
| FiredRules | Count fired rules |
| CalculationObjects | Array calculated objects (p. 1.2) |
Field Rules contains array rules:
{
"Priority":0,
"Source":""
}| Field | Require | Description |
|---|---|---|
| Priority | no (default: 0) | Rule calculation priority. When system calculates rules, Firstly will be calculated rules with highest priority, then with less piority. Rules with equals priority will calculated together. |
| Source | yes | Source code rule. Field is string. Rule in DRL format |
This example illustrates a simple rule with filled priority:
"Rules":[
{
"Priority":1,
"Source":"
dialect \"mvel\"
rule \"test\"
when
$pe:Person()
then
$pe.Age = 1111;
end"
}
] In source code you haven't to put package and import for object, because you can use only objects from JSON.
Contains array objects. It has to have format like:
{
"RootClassName":"Person",
"Schema":"",
"Data":[
{
"Age":38,
"FirstName":"Kelly"
}
]
}| Field | Require | Description |
|---|---|---|
| RootClassName | yes | root class name. You have to put it because it's impossible retrieve base class name from JSON |
| Schema | no | Json schema's object. Recommended to put it if you have large object's array(it reduces calculation time) |
| Data | yes | object's array. Only one type objects possible. Embedded objects are possible |
About json schema you can see:
- Documentation
- Online Editor
- Recommended creates json schema with theia.jsonschemaservice(p. 2)
This example illustrates main object with two embedded objects(array: tags and object: dimensions)
{
"RootClassName":"Coordinate",
"Data":[
{
"id":2,
"name":"An ice sculpture",
"price":12.50,
"tags":[
"cold",
"ice"
],
"dimensions":{
"length":7.0,
"width":12.0,
"height":9.5,
}
}
]
}In rules you can use this objects by fields: tags, dimensions
For creation JSON Schema you can use the theia.jsonschemaservice, it's available in [host]:[port]/jsonschema where host/port you can set in config files. If you will use docker containers it will set up automatically.
This services accessed by using post method and read json from body: Example:
POST /jsonschema HTTP/1.1
Host: [host]:[port]
Content-Type: application/json
Cache-Control: no-cache
{
"Rules":{}
}response will be json schema for this object.
- Query with example creation new object from rule, priority and DRL aggregation function request:
{
"Rules":[
{
"Priority":0,
"Source":"
dialect \"mvel\"
rule \"test\"
when
$pe:Person()
personCount : Number( ) from accumulate ( $person : Person(Age > 30), count($person))
then
$pe.Count = personCount;
end"
},
{
"Priority":1,
"Source":"
dialect \"mvel\"
rule \"test\"
no-loop true
when
$pe:Person(Age < 25)
then
Person person = new Person();
person.Age = 999;
insert(person);
end"
}
],
"CalculationObjects":[
{
"RootClassName":"Person",
"Schema":"",
"Data":[
{
"Age":24,
"FirstName":"Kelly",
"LastName":"Tanner",
"gender":"male",
"company":"SKYBOLD",
"email":"[email protected]",
"phone":"+1 (853) 470-2232",
"address":"616 Verona Place, Whipholt, Pennsylvania, 7892",
"registered":"2015-09-26T03:13:40 -06:00",
"Count":0
}
]
}
]
}- first rule will create new object Person and will add it to calculation session.
- aggregation function will find and calculate count of person, whose age less then 25.
- update all Person's field(Count)
response:
{
"FiredRules": 3,
"CalculationObjects": [
{
"RootClassName": "Person",
"Schema": null,
"Data": [
{
"Age": 24,
"FirstName": "Kelly",
"LastName": "Tanner",
"gender": "male",
"company": "SKYBOLD",
"email": "[email protected]",
"phone": "+1 (853) 470-2232",
"address": "616 Verona Place, Whipholt, Pennsylvania, 7892",
"registered": "2015-09-26T03:13:40 -06:00",
"Count": 1
},
{
"Age": 999,
"FirstName": null,
"LastName": null,
"gender": null,
"company": null,
"email": null,
"phone": null,
"address": null,
"registered": null,
"Count": 1
}
]
}
]
}- Query with example embeded objects, DRL aggregation function, and additional function roundFunc
request:
{
"Rules":[
{
"Source":"
function double roundFunc( double a, int scale ){
return cli.System.Math.Round( a, scale );
}
rule \"Longitude_TEST\"
dialect \"mvel\"
when
$coordinate : Coordinate()
$ds : dimensions(width == 1.0) from $coordinate.dimensions
$sumLatitude : Number( ) from accumulate ( $coord : Coordinate(), sum($coord.warehouseLocation.latitude))
$sumLongitude : Number( ) from accumulate ( $coord : Coordinate(), sum($coord.warehouseLocation.longitude))
then
$ds.zindex = $sumLatitude;
$ds.zindex2 = roundFunc($sumLongitude, 2);
end"
}
],
"CalculationObjects":[
{
"RootClassName":"Coordinate",
"Data":[
{
"id":2,
"name":"An ice sculpture",
"price":12.50,
"tags":[
"cold",
"ice"
],
"dimensions":{
"length":7.0,
"width":12.0,
"height":9.5,
"zindex":0,
"zindex2":0
},
"warehouseLocation":{
"latitude":-78.75,
"longitude":20.4
}
},
{
"id":3,
"name":"A blue mouse",
"price":25.50,
"dimensions":{
"length":3.1,
"width":1.0,
"height":1.0,
"zindex":0,
"zindex2":0
},
"warehouseLocation":{
"latitude":54.4,
"longitude":-32.7
}
}
]
}
]
}response:
{
"FiredRules": 1,
"CalculationObjects": [
{
"RootClassName": "Coordinate",
"Schema": null,
"Data": [
{
"id": 2,
"name": "An ice sculpture",
"price": 12.5,
"tags": [
"cold",
"ice"
],
"dimensions": {
"length": 7,
"width": 12,
"height": 9.5,
"zindex": 0,
"zindex2": 0
},
"warehouseLocation": {
"latitude": -78.75,
"longitude": 20.4
}
},
{
"id": 3,
"name": "A blue mouse",
"price": 25.5,
"tags": null,
"dimensions": {
"length": 3.1,
"width": 1,
"height": 1,
"zindex": -24.35,
"zindex2": -12.3
},
"warehouseLocation": {
"latitude": 54.4,
"longitude": -32.7
}
}
]
}
]
}In this example you can see method from C# language cli.System.Math.Round. For use this opportunity you have to use construction like: [cli].[namespace].[class].[method]