@neo4j/cypher-builder
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A programmatic API for building Cypher queries for Neo4j
83 lines (82 loc) • 2.86 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.When = exports.Case = void 0;
const CypherASTNode_1 = require("../CypherASTNode");
const compile_cypher_if_exists_1 = require("../utils/compile-cypher-if-exists");
const pad_block_1 = require("../utils/pad-block");
/** Case statement
* @group Expressions
* @see {@link https://neo4j.com/docs/cypher-manual/current/syntax/expressions/#query-syntax-case | Cypher Documentation}
*/
class Case extends CypherASTNode_1.CypherASTNode {
constructor(comparator) {
super();
this.whenClauses = [];
this.comparator = comparator;
}
// public when(expr: C extends Expr ? Expr : Predicate): When<C> {
when(...exprs) {
const whenClause = new When(this, exprs);
this.whenClauses.push(whenClause);
return whenClause;
}
else(defaultExpr) {
this.default = defaultExpr;
return this;
}
/**
* @internal
*/
getCypher(env) {
const comparatorStr = (0, compile_cypher_if_exists_1.compileCypherIfExists)(this.comparator, env, { prefix: " " });
const whenStr = this.whenClauses.map((c) => c.getCypher(env)).join("\n");
const defaultStr = (0, compile_cypher_if_exists_1.compileCypherIfExists)(this.default, env, { prefix: "\nELSE " });
const innerStr = (0, pad_block_1.padBlock)(`${whenStr}${defaultStr}`);
return `CASE${comparatorStr}\n${innerStr}\nEND`;
}
}
exports.Case = Case;
/**
* @group Expressions
*/
class When extends CypherASTNode_1.CypherASTNode {
/** @internal */
constructor(parent, predicate) {
super(parent);
this.parent = parent;
this.predicates = predicate;
}
then(expr) {
this.result = expr;
return this.parent;
}
/**
* @internal
*/
getCypher(env) {
const predicateStr = this.predicates.map((p) => p.getCypher(env)).join(", ");
if (!this.result)
throw new Error("Cannot generate CASE ... WHEN statement without THEN");
const resultStr = this.result.getCypher(env);
return `WHEN ${predicateStr} THEN ${resultStr}`;
}
}
exports.When = When;