On a related note, the React docs were very misleading when they stated the following:
"In practice, finding a key is not really hard. Most of the time, the element you are going to display already has a unique id. When that's not the case, you can add a new ID property to your model or hash some parts of the content to generate a key." Source: http://facebook.github.io/react/docs/reconciliation.html#key...
I tried following their advice and used the unique ID of the search results record and it turns out that was the wrong thing to do. It was better to use the index of the current iteration and I think that should always be the recommended thing to do given the performance difference.
I agree there could be a little more clarity in that block of text, but I think the trade-offs section describes it well. Additionally, if there are any nodes in the tree that have a chance of being the same item between renders, you're going to benefit immensely from implementing a `shouldComponentUpdate` in your `SearchResultsItem.jsx` file.
React certainly doesn't win on every performance level, and if you try to compete on performance you're eventually going to lose. A careful developer could implement this list with no framework at all and have performance that beats both.
In the end, it's more about the mental model that best fits you and your team. I find the composite UI of React where I am building every component of other components in Javascript without a templating language to get in my way to be best suited to me.
If Marko works well for your team and you find it easy to get new developers on board and contributing code then that's awesome, keep up the good work.
Really good questions to ask and statements to reassert:
* Does is scale well? * Will this framework / library help me in my career forward? * How hard is it to implement features? * Is the framework / library enjoyable to work in? * Does the framework / library lend itself to allowing elegant solutions? * Does the framework / library provoke a thoughtful and/or refreshing pattern or style in your code? * Is the framework / library sometimes blocking solutions to problems? * Can a new team member readily understand this, explore and contribute after a day or so of training? * How easy is it collaborating with others? * This framework / library is simple and understandable enough to get started quickly * I am intrigued by this framework / library. * There is a lot of support and resources * There aren't a lot of grey areas
As far as I know, React knocks these out of the park.
The conclusion from these tests is that React currently does not scale well on the server (at least for this type of page) due to high CPU and memory usage while requests per second were low for a very modest page of 100 search results items. This is not surprising since the focus of React has been on the client-side performance, but it is important because many projects are adopting React as an "isomorphic" solution.
Hopefully the community and the authors of React can use this information to make React better. There is always something that can be learned from benchmarks like this.
React does do a good job, but I also think Marko+Marko Widgets will be a much better fit for certain types of applications since it also includes a very strong UI component model and it is lighter. If nothing else, hopefully others can learn something from looking at the code and seeing two different approaches.
Also this test could be more efficiently written. First (in SearchResults.jsx), setState accepts a callback in its second parameter, you don't need componentDidUpdate() or this.doneCallback (which is triggering more GC). Second in SearchResultsItem.jsx, you have an empty componentDidMount() function, you should get rid of that. Also this is super optimization, but it's also important that you think deeply about the creation of objects, therefore creating potential garbage that has to be cleaned up after short usage. In SearchResultsItem.jsx, you should just go with a className (className={"search-results-item" + (this.state.purchased && ' user-has-purchased')}) instead of a style object, which becomes useless if you don't have a purchase.
By giving each SearchResultsItem their own state management, you're making it more dirty than you has to be, it should just be a simple list item. Typically in this type of app (Search), the SearchResultsItem component would be stateless (no this.state, getInitialState). When someone clicks handleBuyButtonClick, that communicates the change to the store, which then flows down to SearchResults, which "re-renders" the list of SearchResultsItems.
There are probably a lot more optimizations I could go over, but in short conclusion React's performance is more than the library, it is a mode of thinking.
