我最近通过Heroku成功部署了一个node.js服务器,可以在这里找到该机器:https://congress-tracker-app.herokuapp.com/
它基本上与Twitter的API通信,每次从我预定义的参数集接收到推文时更新.csv文件 - 在这种情况下,推文的ID。然后我使用D3.js显示该CSV以显示数据。
数据正在使用D3 javascript库... d3.queue().defer(d3.csv, "public/data/twitterData.csv").await(update)
然后更新回调函数传递数据,并创建我的可视化。
我有两个问题:
在Heroku应用程序页面上,我的日志显示正在添加数据。出现“文件已保存”消息,当fs.appendFile向我的CSV添加行时,我在代码中触发。这是消息:
正如您所见,CSV文件位于我的应用程序的公共文件夹中。如何确保在应用程序退出后1)服务器继续运行并且2)保存对CSV的更改?
这是我的代码的一部分:
var param = {follow: '21111098,958191744683782144,18061669,21111098,18061669,2891210047,1869975300,19394188,4107251,16056306,259459455,21111098,18061669,2891210047,1869975300,19394188,4107251,16056306,259459455,968650362,343041182,5558312,111671288,476256944,378631423,803694179079458816,30354991,224285242,45645232,235217558,20879626,150078976,278124059,102477372,249787913,381577682,15324851,435500714,823302838524739584,20597460,555355209,15745368,229966028,3001665106,2863210809,1397501864,78403308,253252536,47747074}
var followIds = ['21111098','958191744683782144','18061669','21111098','18061669','2891210047','1869975300','19394188','4107251','16056306','259459455','21111098','18061669','2891210047','1869975300','19394188','4107251','16056306','259459455','968650362','343041182','5558312','111671288','476256944','378631423','803694179079458816','30354991','224285242']
twitterClient.stream('statuses/filter',param,function(stream) {
stream.on('data', function(tweet) {
const fields = ["name","text","URL","time"]
for(i = 0; i <followIds.length; i++){
if(followIds[i] == tweet.user.id_str){ // if so, get contents
// WRITE TO CSV HERE:
let name = tweet.user.name;
let text = tweet.text;
let URL = `https://twitter.com/${tweet.user.screen_name}/status/${tweet.id_str}`
let time = tweet.created_at;
update = [{name,text,URL,time}]
var toCsv = {
data: update,
fields: fields,
hasCSVColumnTitle: false
};
var csv = json2csv(toCsv) + "\r\n";
fs.appendFile('public/data/twitterData.csv',csv,function(err){
if (err) throw err;
console.log('File Saved')
})
}
}
});