Export Variable NodeJS
I am writing a nodejs module and I need to pass variable data from main file to functions, I do this:
var region;
var api_key;
exports.region = region;
exports.api_key = api_key;
module.exports = {
getSummonerId: function(sum, callback) {
var summoners = {};
var summoner = sum.replace(/\s+/g, '');
request("https://na.api.pvp.net/api/lol/"+region+"/v1.4/summoner/by-name/"+summoner+"?api_key="+api_key, function(error, response, body) {
summoners[summoner] = JSON.parse(body);
callback(summoners[summoner][summoner].id);
});
}
}
And in the main file :
var lol = require('./apiwrapper.js');
lol.api_key = "example";
lol.region = "las";
lol.getChampions(function(data) {
console.log(data);
})
But from apiwrapper.js these two variable values are always " undefined ".
Can anyone point me in the right direction?
Thanks in advance.
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The value to be imported into another module is module.exports
. So, what you assign module.exports
is exported. Everything that was previously assigned is lost.
The connection between module.exports
and exports
is that they first refer to the same object:
var exports = module.exports = {};
So, assigning a property to any of them mutates the same object. However, you are assigning a new object module.exports
, so now they both refer to different objects.
A simple solution is to assign a new object exports
and then assign other properties:
exports = module.exports = {...};
exports.region = region;
If you want to preserve the order of the statements, then you need to extend the default export object instead of creating a new one:
Object.assign(exports, { ... });
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Why not use:
module.exports = {
region: my_region,
api_key: my_api_key,
getSummonerId: function(sum, callback) {
var summoners = {};
var summoner = sum.replace(/\s+/g, '');
request("https://na.api.pvp.net/api/lol/"+region+"/v1.4/summoner/by-name/"+summoner+"?api_key="+api_key, function(error, response, body) {
summoners[summoner] = JSON.parse(body);
callback(summoners[summoner][summoner].id);
});
}
}
in your case "module.exports" overwrites previously exported variables. It is for this reason that you get undefined for them.
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