jsondiffpatch/src/pipe.js

Diff & Patch for Javascript objects

var Pipe = function Pipe(name) {
  this.name = name;
  this.filters = [];
};

Pipe.prototype.process = function(input) {
  if (!this.processor) {
    throw new Error('add this pipe to a processor before using it');
  }
  var debug = this.debug;
  var length = this.filters.length;
  var context = input;
  for (var index = 0; index < length; index++) {
    var filter = this.filters[index];
    if (debug) {
      this.log('filter: ' + filter.filterName);
    }
    filter(context);
    if (typeof context === 'object' && context.exiting) {
      context.exiting = false;
      break;
    }
  }
  if (!context.next && this.resultCheck) {
    this.resultCheck(context);
  }
};

Pipe.prototype.log = function(msg) {
  console.log('[jsondiffpatch] ' + this.name + ' pipe, ' + msg);
};

Pipe.prototype.append = function() {
  this.filters.push.apply(this.filters, arguments);
  return this;
};

Pipe.prototype.prepend = function() {
  this.filters.unshift.apply(this.filters, arguments);
  return this;
};

Pipe.prototype.indexOf = function(filterName) {
  if (!filterName) {
    throw new Error('a filter name is required');
  }
  for (var index = 0; index < this.filters.length; index++) {
    var filter = this.filters[index];
    if (filter.filterName === filterName) {
      return index;
    }
  }
  throw new Error('filter not found: ' + filterName);
};

Pipe.prototype.list = function() {
  var names = [];
  for (var index = 0; index < this.filters.length; index++) {
    var filter = this.filters[index];
    names.push(filter.filterName);
  }
  return names;
};

Pipe.prototype.after = function(filterName) {
  var index = this.indexOf(filterName);
  var params = Array.prototype.slice.call(arguments, 1);
  if (!params.length) {
    throw new Error('a filter is required');
  }
  params.unshift(index + 1, 0);
  Array.prototype.splice.apply(this.filters, params);
  return this;
};

Pipe.prototype.before = function(filterName) {
  var index = this.indexOf(filterName);
  var params = Array.prototype.slice.call(arguments, 1);
  if (!params.length) {
    throw new Error('a filter is required');
  }
  params.unshift(index, 0);
  Array.prototype.splice.apply(this.filters, params);
  return this;
};

Pipe.prototype.clear = function() {
  this.filters.length = 0;
  return this;
};

Pipe.prototype.shouldHaveResult = function(should) {
  if (should === false) {
    this.resultCheck = null;
    return;
  }
  if (this.resultCheck) {
    return;
  }
  var pipe = this;
  this.resultCheck = function(context) {
    if (!context.hasResult) {
      console.log(context);
      var error = new Error(pipe.name + ' failed');
      error.noResult = true;
      throw error;
    }
  };
  return this;
};

exports.Pipe = Pipe;