handlebars.js/lib/handlebars/compiler/printer.js

import Visitor from "./visitor";

export function print(ast) {
  return new PrintVisitor().accept(ast);
}

export function PrintVisitor() {
  this.padding = 0;
}

PrintVisitor.prototype = new Visitor();

PrintVisitor.prototype.pad = function(string) {
  var out = "";

  for(var i=0,l=this.padding; i<l; i++) {
    out = out + "  ";
  }

  out = out + string + "\n";
  return out;
};

PrintVisitor.prototype.Program = function(program) {
  var out = '',
      body = program.body,
      i, l;

  if (program.blockParams) {
    var blockParams = 'BLOCK PARAMS: [';
    for(i=0, l=program.blockParams.length; i<l; i++) {
       blockParams += ' ' + program.blockParams[i];
    }
    blockParams += ' ]';
    out += this.pad(blockParams);
  }

  for(i=0, l=body.length; i<l; i++) {
    out = out + this.accept(body[i]);
  }

  this.padding--;

  return out;
};

PrintVisitor.prototype.MustacheStatement = function(mustache) {
  return this.pad('{{ ' + this.accept(mustache.sexpr) + ' }}');
};

PrintVisitor.prototype.BlockStatement = function(block) {
  var out = "";

  out = out + this.pad('BLOCK:');
  this.padding++;
  out = out + this.pad(this.accept(block.sexpr));
  if (block.program) {
    out = out + this.pad('PROGRAM:');
    this.padding++;
    out = out + this.accept(block.program);
    this.padding--;
  }
  if (block.inverse) {
    if (block.program) { this.padding++; }
    out = out + this.pad('{{^}}');
    this.padding++;
    out = out + this.accept(block.inverse);
    this.padding--;
    if (block.program) { this.padding--; }
  }
  this.padding--;

  return out;
};

PrintVisitor.prototype.PartialStatement = function(partial) {
  var sexpr = partial.sexpr,
      content = 'PARTIAL:' + sexpr.id.original;
  if(sexpr.params[0]) {
    content += ' ' + this.accept(sexpr.params[0]);
  }
  if (sexpr.hash) {
    content += ' ' + this.accept(sexpr.hash);
  }
  return this.pad('{{> ' + content + ' }}');
};

PrintVisitor.prototype.ContentStatement = function(content) {
  return this.pad("CONTENT[ '" + content.value + "' ]");
};

PrintVisitor.prototype.CommentStatement = function(comment) {
  return this.pad("{{! '" + comment.value + "' }}");
};

PrintVisitor.prototype.sexpr = function(sexpr) {
  var params = sexpr.params, paramStrings = [], hash;

  for(var i=0, l=params.length; i<l; i++) {
    paramStrings.push(this.accept(params[i]));
  }

  params = "[" + paramStrings.join(", ") + "]";

  hash = sexpr.hash ? " " + this.accept(sexpr.hash) : "";

  return this.accept(sexpr.id) + " " + params + hash;
};

PrintVisitor.prototype.PathExpression = function(id) {
  var path = id.parts.join('/');
  return (id.data ? '@' : '') + 'PATH:' + path;
};


PrintVisitor.prototype.hash = function(hash) {
  var pairs = hash.pairs;
  var joinedPairs = [], left, right;

  for(var i=0, l=pairs.length; i<l; i++) {
    left = pairs[i][0];
    right = this.accept(pairs[i][1]);
    joinedPairs.push( left + "=" + right );
  }

  return "HASH{" + joinedPairs.join(", ") + "}";
};

PrintVisitor.prototype.StringLiteral = function(string) {
  return '"' + string.value + '"';
};

PrintVisitor.prototype.NumberLiteral = function(number) {
  return "NUMBER{" + number.value + "}";
};

PrintVisitor.prototype.BooleanLiteral = function(bool) {
  return "BOOLEAN{" + bool.value + "}";
};