mapstuff | : earth_americas : : rocket : Experiments with GraphQL | GraphQL library

Following the Rx Design Guidelines, you should never put code that causes side effects in a map. You should always make side-effecting code explicit.

Code that causes side effects should only occur when creating an observable, in a subscribe, or rarely in a do operator. This will make it clear to anybody reading the code what's going on and will also make it easier to figure out what part of the chain is, or is not, testable.

Side effects in the do operator are fine, in fact they are expected, however be sure you understand that these side effects will occur for every subscription of the Observable. IMO, if you can put the code in a subscribe, do that instead.

You'll need to maintain a map of month to consumption totals whiel you loop through the data, and then at the end convert that map into an array of the object you want. Here's an example:

Thanks to some commentors, I've found that nesting with open() outside of iterparse() does the trick.

My antivirus program was likely the culprit, accessing the file each time it was closed, which occasionally caused an access conflict on the next file open operation.

I didn't like opening and closing the file for each element because of the operation cost, and I originally had parsed the XML from within the file open when I was writing to a single file. But, when I decided to write to multiple files, I didn't want to parse the XML over again for each JSON file I wanted to write from it.

Seems like a no-brainer now, but nesting file opens works and saves compute. It might build up the indents if you want to write a lot of files, but c'est la vie.

The stage created by handle() method is always executed regardless of exception occurs or not, whereas exceptionally() stage is only executed when there's an exception.

I couldn't reproduce your error, exceptionally block executes for me whenever the exception is not caught.

In my opinion, you should use either handle or exceptionally.

handle() method enables you to provide a default value on exception and exceptionally() method is similar to handle but less verbose