randomly generate the unique id for the uploaded uploaded images

Question

I want to generate the random id for the uploaded images with their file names.

my code is

var getUniqueMacroName = function(filename){
    var Name = $.trim(filename.replace(/.[^.]+$/,'').replace(/ /g, "").replace(/[^\w]|_/g, "").toUpperCase());
    var Ext = $.trim(filename.replace(/^.*\./,'').toUpperCase());
    var mac= _.map($("#data").DataTable().data(), function(a){return a[0]});

    var fileRand = Name.substring(0, (10 - fileExt.length));

    while(_.contains(mac, ("GM" + fileRand + fileExt))){
        var rand = Math.min(Math.floor((Math.random() * fileRand.length) + 5), (fileRand.length - 1));
        fileRand =  (fileRand.substring(0, rand) + rand + fileRand.substring(rand, fileRand.length)).substring(0, (10 - Ext.length));
    }
    return "GM" + fileRand + Ext;
}

If i upload the images like

gallery image 320 1.jpg
gallery image 320 2.jpg
gallery image 320 3.jpg
gallery image 320 4.jpg
gallery image 320 5.jpg
gallery image 320 6.jpg

the sixth image is execute infinite times in the while condition.This will happen when the uploaded image name have almost same.So the browser will be not respond.

Is there any way to generate the unique id for any type of file names(including the same filename) in javascript or jquery.

You can also use UUIDs: http://stackoverflow.com/questions/105034/create-guid-uuid-in-javascript — AnthonyDJ, Sep 10 '15 at 11:41

hurricane · Answer 1 · 2015-09-11T06:23:52.203

0

Editted by user suggestion usefull answer;

Yes you can use TimeStamp for unique ID with Date.now(); It generate milliseconds and they are always unique;

The now() method returns the milliseconds elapsed since 1 January 1970 00:00:00 UTC up until now as a Number.

var getUniqueMacroName = function(filename){
    var Name = $.trim(filename.replace(/.[^.]+$/,'').replace(/ /g, "").replace(/[^\w]|_/g, "").toUpperCase());
    var Ext = $.trim(filename.replace(/^.*\./,'').toUpperCase());
    var mac= _.map($("#data").DataTable().data(), function(a){return a[0]});
    // dont need anymore control unique
    var fileRand = Date.getTime();
    fileRand = fileRand.substr(fileRand.length - 10);
    return "GM" + fileRand + Ext;
}

edited Sep 11 '15 at 06:23

answered Sep 10 '15 at 11:50

hurricane

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how can i restrict in 14 characters – kalles Sep 10 '15 at 12:27
fileRand = fileRand.substr(fileRand.length - 14); you can take last 14 id with it. – hurricane Sep 10 '15 at 12:30
thank you @ hurricane. I solve this problem in another way using "new Date().getTime()". – kalles Sep 10 '15 at 13:48
@kalles Have a nice day. – hurricane Sep 11 '15 at 06:24
Date.getTime() isn't unique. See [my answer](http://stackoverflow.com/a/20523888/1183010). – R. Oosterholt Sep 11 '15 at 06:29

score 0 · Answer 2 · answered Sep 11 '15 at 06:35

0

Your approach could work if you generate a longer 'random' number?

var random = Math.random()*100000000000000000;  // e.g. 6137274974025786

answered Sep 11 '15 at 06:35

R. Oosterholt

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It's generate random number not unique number. If you use 10 number for random probability is 1/10. If you use 100000000000000000 number for random probability is 1/100000000000000000 so it's not a unique! If you use dateTime it's always count beacuse time always increase. – hurricane Sep 11 '15 at 10:50
no, Date.getTime() is not unique (not always incrementing), see [my answer](http://stackoverflow.com/a/20523888/1183010). – R. Oosterholt Sep 11 '15 at 11:33

randomly generate the unique id for the uploaded uploaded images

2 Answers2