Vfrdtyky

QUESTION:

After reading this:

https://www.npmjs.com/package/riot-lol-api#caching

I am still confused. This is my first time trying to cache api responses.

For example, I do not know what values are available for YOUR_CACHE_STRATEGY and it is not explained in the docs.

Essentially, I would be looking for an example, like how can I cache and serve for 5 min the response from /lol/summoner/v3/summoners/by-name/ ?

CODE:

riotRequest.request(region.toLowerCase(), 'summoner', '/lol/summoner/v3/summoners/by-name/'+encodeURI(player), function(err, data) {

            if (!err) {

                var summonerID = data.id;

            } else {

                console.error("ERROR1: "+err);

                res.render("page", {errorMessage: "Player not found !"});

            }

        });

The documentation is not very detailed indeed. What you need to do is basically implement the cache object as specified in the code sample from the doc (the commented area).

Below is an example of caching to an array (in memory). You could also save this array to a file or into a Redis database as suggested in the doc.

//cacheData holds objects of type {key: 123, value: "request data"}

var cacheData = 

var cacheIndex = 0



function deleteFromCache(key) {

  for (var i = 0; i < cacheData.length; i++) {

    if (cacheData[i].key == key) {

      cacheData.splice(i, 1);

      return;

    }

  }

}



var cache = {

  get: function(region, endpoint, cb) {       

    for (var entry of cacheData) {

      if (entry.value == data) {

        //we have a cache hit

        return cb(null, entry.value);

      }      

    }

    return cb(null, null);

  },

  set: function(region, endpoint, cacheStrategy, data) {

    var key = cacheIndex++;

    var value = data;



    cacheData.push({key, value});



    //cacheStrategy is a number representing the number of seconds to keep the data in cache

    setTimeout(() => {

      deleteFromCache(key);

    }, cacheStrategy * 1000);    

  }

};

YOUR_CACHE_STRATEGY is an object that is passed to your set function in the cacheStrategy parameter. They suggest it can be a number representing the lifespan of the cache entry, so I implemented a timer to delete the cache entry after a number of seconds equal to cacheStrategy.

You would call the request using this number:

riotRequest.request(region.toLowerCase(), 'summoner', '/lol/summoner/v3/summoners/by-name/'+encodeURI(player), 30, function(err, data) {//.....

To enable caching you need to pass the cache object to the constructor of RiotRequest :

var riotRequest = new RiotRequest('my_api_key', cache);