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import GraphQueryStreamingResult from "@arcgis/core/rest/knowledgeGraph/GraphQueryStreamingResult.js";
Inheritance:
GraphQueryStreamingResultAccessor
Since
ArcGIS Maps SDK for JavaScript 4.25

The result of a executeSearchStreaming() or executeQueryStreaming() on a knowledge graph service. Contains a readable stream of objects that match the search or query criteria. The readable stream must be decoded using a getReader() function in order to access the returned graph data.

See also
Examples
// sample executeSearchStreaming that would return a GraphQueryStreamingResult
KnowledgeGraphModule.executeSearchStreaming(
knowledgeGraph,
{
searchQuery: "solar",
typeCategoryFilter: "entity",
returnSearchContext: false,
start: 1, // index of the first record to return
num: 200, // return 200 records.
namedTypesFilter: ["Company", "Supplier", "Part"],
idsFilter: ["{9D2D6AFD-41F1-49A4-8412-CACCC9906E88}",
"{25WNN24S-41F1-49A4-8412-ANIWN9906E88}",
"{NS51HE8D-41F1-49A4-8412-5HNIRH9906E8}"]
}
).then((streamingSearchResult)=>{
// the result of a streaming search is a readableStream which requires decoding.
readStream(streamingSearchResult)
})
// the returned readable stream before decoding
{
resultsRowsStream: {
locked: true
}
}
// sample streaming query using bind parameters
// to search for entities with a the `name` property that matches a specific string
// or have their geometry within a bounding box.
// get all parts bought by each supplier.
// query returns both the supplier and the part it buys.
const query = `MATCH (s:Supplier)-[:buys_part]-(p:Part) RETURN s,p`;
KnowledgeGraphModule.executeQueryStreaming(knowledgeGraph, query})
.then((streamingQueryResult)=>{
// streaming query returns a readableStream which must be read to access the returned graph data
readStream(streamingQueryResult);
})
// a function to read the readable stream returned from the above query
const readStream = async (streamingQueryResult) => {
let time = Date.now();
let reader = streamingQueryResult.resultRowsStream.getReader();
try {
while (true) {
const { done, value } = await reader.read();
if (done) {
console.log(`Completed database requests: ${(Date.now() - time) / 1000} seconds`, value);
break;
}
console.log(`Chunk returned in: ${(Date.now() - time) / 1000} seconds`, value);
// use the results
// list the parts bought by each supplier
let supplierParts = {};
// each element of the result array will contain one supplier and one part it buys
for (var v in value){
let supplier = value[v][0].properties.Name
let part = value [v][1].properties.Name
if(!(supplier in supplierParts)){
supplierParts[supplier] = [];
}
// collect parts by supplier that buys them
supplierParts[supplier].push(part);
console.log(supplierParts);
// result printed to the console: {Supplier 1:[Part1], Supplier 3:[Part2, Part3]}
}
} catch (err) {
if (err.name === "AbortError") {
console.log("Request aborted as expected");
} else {
throw err;
}
}
};
// sample result of streaming search result chunk read and printed to the console.
// the reader will continue to return chunks until the stream is complete
// and all matching results are returned
"Streaming chunk returned in: 0.082 seconds"
[
[{
"declaredClass": "esri.rest.knowledgeGraph.Entity",
"properties": {
"Name": "Suncommon",
"Employee_Count": 400,
"energyType": "solar"
},
"typeName": "Company",
"id": "{25WNN24S-41F1-49A4-8412-ANIWN9906E88}"
}],
[{
"declaredClass": "esri.rest.knowledgeGraph.Entity",
"properties": {
"Name": "Quality Solar Supply",
"Supplier_code": "158B",
"City": "New Orleans",
},
"typeName": "Supplier",
"id": "{GE5G1E8D-41F1-49A4-8412-QNG5EG48SG8S}"
}],
[{
"declaredClass": "esri.rest.knowledgeGraph.Entity",
"properties": {
"Name": "Solar panel",
"panel_type": "Polycrystalline",
"price_per_unit": 400
},
"typeName": "Part",
"id": "{9D2D6AFD-41F1-49A4-8412-CACCC9906E88}",
}]
]

Constructors

Constructor

Constructor
Parameters
ParameterTypeDescriptionRequired
properties
See the properties table for a list of all the properties that may be passed into the constructor.

Properties

Any properties can be set, retrieved or listened to. See the Watch for changes topic.
PropertyTypeClass
declaredClass
readonly inherited

declaredClass

readonlyinherited Property
Type
string
Inherited from: Accessor

The name of the class. The declared class name is formatted as esri.folder.className.

resultRowsStream

Property
Type
ReadableStream

Readable stream of objects matching executeSearchStreaming() or executeQueryStreaming() criteria. Requires decoding using the getReader() method.

Example
// example of result decoding.
// execute streaming query on a knowledge graph
kgModule.executeQueryStreaming(
kg,
{
openCypherQuery: "MATCH (n) RETURN n LIMIT 500",
}
).then((streamingQueryResult) => {
readStream(streamingQueryResult);
})
//read the ReadableStream result
const readStream = async (streamingQueryResult) => {
let time = Date.now();
// create new stream reader
let reader = streamingQueryResult.resultRowsStream.getReader();
try {
// while the stream is returning data
while (true) {
const { done, value } = await reader.read();
// the stream has finished retrieving all matching records from the database
if (done) {
console.log("Client Query stream completed");
break;
}
// do something with the result records returned in each chunk
console.log(
`Client Query Result at Time ${Date.now() - time}:`,
value
);
}
// if stream is aborted by user return message, otherwise throw error
} catch (err) {
if (err.name === "AbortError") {
console.log("Request aborted as expected");
} else {
throw err;
}
}
};