@neo4j/graphql
Version:
A GraphQL to Cypher query execution layer for Neo4j and JavaScript GraphQL implementations
80 lines • 3.54 kB
JavaScript
;
/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [http://neo4j.com]
*
* This file is part of Neo4j.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.CompositeCypherOperation = void 0;
const cypher_builder_1 = __importDefault(require("@neo4j/cypher-builder"));
const operations_1 = require("../operations");
class CompositeCypherOperation extends operations_1.Operation {
constructor({ selection, partials, cypherAttributeField, }) {
super();
this.selection = selection;
this.partials = partials;
this.cypherAttributeField = cypherAttributeField;
}
getChildren() {
return [this.selection, ...this.partials];
}
transpile(context) {
// eslint-disable-next-line prefer-const
let { selection: matchClause, nestedContext } = this.selection.apply(context);
const returnVariable = new cypher_builder_1.default.Variable();
const partialContext = nestedContext.setReturn(returnVariable);
if (!this.partials.length) {
return {
clauses: [cypher_builder_1.default.utils.concat(matchClause, new cypher_builder_1.default.Return(nestedContext.returnVariable))],
projectionExpr: nestedContext.returnVariable,
};
}
const partialClauses = this.partials.map((partial) => {
const { clauses } = partial.transpile(partialContext);
return cypher_builder_1.default.utils.concat(new cypher_builder_1.default.With("*"), ...clauses);
});
const partialsSubquery = new cypher_builder_1.default.Call(new cypher_builder_1.default.Union(...partialClauses), "*").return(partialContext.returnVariable);
const returnExpr = this.getReturnExpression(nestedContext, returnVariable);
const subquery = new cypher_builder_1.default.Call(partialsSubquery, [nestedContext.target]).return([
returnExpr,
nestedContext.returnVariable,
]);
return {
clauses: [cypher_builder_1.default.utils.concat(matchClause, subquery)],
projectionExpr: nestedContext.returnVariable,
};
}
getReturnExpression(context, returnVariable) {
return this.wrapWithHeadIfNeeded(context, this.wrapWithCollectIfNeeded(context, returnVariable));
}
wrapWithCollectIfNeeded(context, expr) {
if (context.shouldCollect) {
return cypher_builder_1.default.collect(expr);
}
return expr;
}
wrapWithHeadIfNeeded(context, expr) {
if (context.shouldCollect && !this.cypherAttributeField.typeHelper.isList()) {
return cypher_builder_1.default.head(expr);
}
return expr;
}
}
exports.CompositeCypherOperation = CompositeCypherOperation;
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