i have read lots of stackoverflow questions related to
servervalue.timestamp but can't figure out how use in app.
i need timestamp of creation of post. timestamp should added same place uid , author etc. of post.
code snippet writes post firebase database:
private void writenewpost(string userid, string username, string title, string body) { // create new post @ /user-posts/$userid/$postid , @ // /posts/$postid simultaneously string key = mdatabase.child("posts").push().getkey(); post post = new post(userid, username, title, body); map<string, object> postvalues = post.tomap(); map<string, object> childupdates = new hashmap<>(); childupdates.put("/posts/" + key, postvalues); childupdates.put("/user-posts/" + userid + "/" + key, postvalues); mdatabase.updatechildren(childupdates); } my post.java file
@ignoreextraproperties public class post { public string uid; public string author; public string title; public string body; public int starcount = 0; public map<string, boolean> stars = new hashmap<>(); public long timestamp; public post() { // default constructor required calls datasnapshot.getvalue(post.class) } public post(string uid, string author, string title, string body) { this.uid = uid; this.author = author; this.title = title; this.body = body; } // [start post_to_map] @exclude public map<string, object> tomap() { hashmap<string, object> result = new hashmap<>(); result.put("uid", uid); result.put("author", author); result.put("title", title); result.put("body", body); result.put("starcount", starcount); result.put("stars", stars); return result; } // [end post_to_map] }
how should use
servervalue.timestamp in code time of creation of post.
servervalue.timestamp placeholder value. when firebase server processes update request , finds servervalue.timestamp value, replaces current server clock.
in writenewpost() method add line set creation time:
map<string, object> postvalues = post.tomap(); postvalues.put("timestamp", servervalue.timestamp); if use post.tomap() create posts, , not updates, put similar statement there instead of in writenewpost().
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