使用Firebase過期網址

Question

某人如何創建指向Firebase數據的臨時網址，但是數據（和網址）在特定時間後即5分鐘或15分鐘後會被銷燬？

Answer 1

根據數據的存儲方式，有幾種不同的選項可以通過時間戳刪除數據。

假設數據是無序的，你所儲存的時間戳字段中的每個記錄，那麼你可以簡單地開始從第一條記錄閱讀和刪除它們，直到你找到你想保留一個：

<script> 
var FB = new Firebase(YOUR_URL); 
var childRef = FB.child(TABLE_WITH_RECORDS_TO_DELETE); 
var oneWeekAgo = new Date().getTime()-1000*60*60*24*7; // one week ago 

var fx = function(snapshot) { // keep a ref to this so we can call off later 
    var v = snapshot.val(); 
    if(v.expires_on_date < oneWeekAgo) { 
     // delete the record 
     snapshot.ref().remove(); 
    } 
    else { 
     // we found the first keeper, so we are done 
     childRef.off('child_added', fx); 
    } 
} 

// fetched records and test to see how old they are 
childRef.on('childAdded', fx); 
</script> 

如果數據按時間戳排序，你可以檢索和刪除它們如下：

var FB = new Firebase(YOUR_URL); 
var childRef = FB.child(TABLE_WITH_RECORDS_TO_DELETE); 
var oneWeekAgoMinusOne = new Date().getTime()-1000*60*60*24*7-1; // one week ago 

// fetched using endAt, so only retrieving older than 1 week 
childRef.endAt(oneWeekAgoMinusOne).on('childAdded', function(snapshot) { 
    // delete the record 
    snapshot.ref().remove(); 
});