How to work with an XML file

Hi Mike,

It would almost certainly be easier to programmatically filter the data in JSON format. There are a variety of converters out there that you could use, including nom packages (commonly referred to as node package manager).

Once you get it into JSON format, you could do something like this:

(Dependent on you having node installed and importing node fs as fs)

Read the JSON file with fs.readFileSync() and store it in a variable - let's say it is called originalData. For the purpose of this example, I will just set it to an array that is representative of what you would receive from reading the given file.

PS: If you know how to handle asynchrony well, you can use fs.readfile() instead of fs.readFileSync(), but it should not be that big of a deal for this task either way.

var originalData = [
  {
    customerName: 'Bob',
    type: 'normal'
  },
  {
    customerName: 'Sue',
    type: 'super'
  },
    {
    customerName: 'Ralph',
    type: 'super'
  },
  {
    customerName: 'Sue',
    type: 'super'
  }
];

Your list of data is certainly more complex than this, but the basic idea of filtering an array of objects (should convert the JSON to an actionable array automatically, but you can always use originalData = JSON.parse(originalData) to be safe.) is the same. In this case, we will filter (a method on the Array prototype) out only the customers that are the type 'super' and store it in a variable called filteredData

var isSuper = function(customer) {
  return customer.type === 'super';
};

var filteredData = originalData.filter(isSuper)

Once you run this code, the filteredData will contain an array of the Objects Sue and Ralph. Since Bob and Brock were not of the 'super' type, they were not added the the new array that we build.

The callback function (in our case isSuper) is key to what items are added to the new array. Items that evaluate to true will be added, while those that evaluate to false will not. For example:

var allAdded = function(customer) {
  return true;
};

var filteredData = originalData.filter(allAdded)

will result in all customers being added to the filteredData array - while

var noneAdded = function(customer) {
  return false;
};

var filteredData = originalData.filter(noneAdded)

will result in an empty array.

Once you complete the filtration that you want, then you would use fs.writefile(path, filteredData) to write the filteredData out to a new file.