[prev in list] [next in list] [prev in thread] [next in thread] 

List:       myfaces-user
Subject:    Re: How to make submit button only work if connection is available?
From:       Mark Struberg <struberg () yahoo ! de ! INVALID>
Date:       2020-01-20 7:35:28
Message-ID: 9984E006-D13B-4631-98D7-4EDEBA70C96C () yahoo ! de
[Download RAW message or body]

FTR, I now did the following trick. Of course this could be enhanced with multilinguality etc. But it works for me.

function submitIfOnline() {
    var xmlHttp = new XMLHttpRequest();
    xmlHttp.open("HEAD", "index.http", false); // synchronous
    try {
        xmlHttp.send();
        if (xmlHttp.status == 200) {
            return true;
        }
    } catch (e) {
        // nothiing to do;
    }

    alert("No connection available, please try again later!");
    return false;
}



plus

<h:form onsubmit="return submitIfOnline()">

The index.http heck is a convention I use in all projects.
Works so far.

LieGrue,
strub



> Am 19.01.2020 um 17:32 schrieb Thomas Andraschko <andraschko.thomas@gmail.com>:
> 
> Hi,
> 
> I never needed something similar but i would do it the same.
> Maybe there are nicer ways, i would try to Google about it first.
> 
> 
> Mark Struberg <struberg@yahoo.de.invalid> schrieb am So., 19. Jan. 2020,
> 16:34:
> 
>> Hi folks!
>> 
>> I'm right now designing a small only survey form with JSF-2.3. The problem
>> is that the survey should gather information from a cellar. And often there
>> is no WiFi nor mobile connection in those rooms. Thus it should not loose
>> data if the user presses the 'Save' button and the connection is not
>> available.
>> 
>> How to do this best?
>> 
>> I thought about an onclick which checks the connection via a ping to a
>> servlet (just returning true) and only then do a jsf.js submit(). If the
>> connection is not present it will present an alert() stating the user
>> should try later when he again has a connection.
>> 
>> Are there some better ways to do this?
>> 
>> txs and LieGrue,
>> strub
>> 
>> 

[prev in list] [next in list] [prev in thread] [next in thread]