@adobe/htlengine/src/parser/commands/DebugCommandVisitor.js

Javascript Based HTL (Sightly) parser

/*
 * Copyright 2018 Adobe. All rights reserved.
 * This file is licensed to you 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 REPRESENTATIONS
 * OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */

const OutText = require('./OutText');
const VariableBinding = require('./VariableBinding');
const Conditional = require('./Conditional');
const Loop = require('./Loop');
const OutputVariable = require('./OutputVariable');
const ExpressionFormatter = require('../../compiler/ExpressionFormatter');

function escapeJavaString(s) {
  return JSON.stringify(s);
}

const INDENTS = [''];
for (let i = 0; i < 50; i += 1) {
  INDENTS[i + 1] = `${INDENTS[i]}  `;
}

module.exports = class DebugCommandVisitor {
  constructor() {
    this._result = '';
    this._indent = 0;
  }

  out(msg) {
    this._result += `${INDENTS[this._indent] + msg}\n`;
  }

  get result() {
    return this._result;
  }

  visit(cmd) {
    if (cmd instanceof OutText) {
      this.out(`$.out(${escapeJavaString(cmd.text)});`);
    } else if (cmd instanceof VariableBinding.Start) {
      const exp = ExpressionFormatter.format(cmd.expression);
      this.out(`{ const ${cmd.variableName} = ${exp};`);
      this._indent += 1;
    } else if (cmd instanceof VariableBinding.Global) {
      const exp = ExpressionFormatter.format(cmd.expression);
      this.out(`global.${cmd.variableName} = ${exp};`);
    } else if (cmd instanceof VariableBinding.End) {
      this._indent -= 1;
      this.out('}');
    } else if (cmd instanceof Conditional.Start) {
      const exp = ExpressionFormatter.format(cmd.expression);
      const neg = cmd.negate ? '!' : '';
      this.out(`if (${neg}${exp}) {`);
      this._indent += 1;
    } else if (cmd instanceof Conditional.End) {
      this._indent -= 1;
      this.out('}');
    } else if (cmd instanceof OutputVariable) {
      this.out(`$.out(${cmd.variableName});`);
    } else if (cmd instanceof Loop.Start) {
      this.out(`for ((${cmd.indexVariable},${cmd.itemVariable}) in ${cmd.listVariable}) {`);
      this._indent += 1;
    } else if (cmd instanceof Loop.End) {
      this._indent -= 1;
      this.out('}');
    } else {
      throw new Error(`unknown command: ${cmd}`);
    }
  }
};