@neo4j/cypher-builder
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A programmatic API for building Cypher queries for Neo4j
66 lines (65 loc) • 2.38 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.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.HasLabel = void 0;
const CypherASTNode_1 = require("../CypherASTNode");
const add_label_token_1 = require("../utils/add-label-token");
const escape_1 = require("../utils/escape");
/** Generates a predicate to check if a node has a label or a relationship has a type
* @see {@link https://neo4j.com/docs/cypher-manual/current/clauses/where/#filter-on-node-label | Cypher Documentation}
* @group Expressions
* @example
* ```cypher
* MATCH(this)
* WHERE this:MyNode
* ```
*/
class HasLabel extends CypherASTNode_1.CypherASTNode {
/**
* @internal
*/
constructor(node, expectedLabels) {
super();
this.validateLabelsInput(expectedLabels);
this.node = node;
this.expectedLabels = expectedLabels;
}
/** @internal */
getCypher(env) {
const nodeId = this.node.getCypher(env);
const labelsStr = this.generateLabelExpressionStr(env);
return `${nodeId}${labelsStr}`;
}
generateLabelExpressionStr(env) {
if (Array.isArray(this.expectedLabels)) {
const escapedLabels = this.expectedLabels.map((label) => (0, escape_1.escapeLabel)(label));
return (0, add_label_token_1.addLabelToken)(env.config.labelOperator, ...escapedLabels);
}
else {
return (0, add_label_token_1.addLabelToken)(env.config.labelOperator, this.expectedLabels.getCypher(env));
}
}
validateLabelsInput(expectedLabels) {
if (Array.isArray(expectedLabels) && expectedLabels.length === 0) {
throw new Error("HasLabel needs at least 1 label");
}
}
}
exports.HasLabel = HasLabel;