onerror event show picture - javascript

Question

I have a javascript code that gives a link to a page, if the page does not answer it gives error and try again. I want to receive the error display a message on the screen

I found some questions about it here but could not apply them in my code. This is my code where I can insert the code so that if there is error, show an image on the screen using document.write

window.setInterval(function() {
    requestURL = "https://api.spark.io/v1/devices/" + deviceID1 + "/" + getFunc + "/?access_token=" + accessToken;
    $.getJSON(requestURL, function(json) {
        var vdadosdospark=json.result;//coloca resultado do json na variavel
        var vdadosdospark=vdadosdospark.replace("-", '')//exclui caractere -
        var resultadoA = vdadosdospark.substr(9, 6);//seleciona os caracteres referentes a amperagem
        var resultadoB = vdadosdospark.substr(24, 1);

        if (resultadoB==1){
            document.write("<IMG ALIGN='center' "+
            "style='position:absolute; left: 400; top: 100' " +
            "SRC='http://www.uairobotics.com/tomada/Images/farol.png'> " +
            "<BR><BR>")
        }else
        {
            document.write("<IMG ALIGN='center' "+
            "style='position:absolute; left: 400; top: 100' " +
            "SRC='http://www.uairobotics.com/tomada/Images/f.png'> " +
            "<BR><BR>"); 
        }
    });
}, 5000);

Answer 1

use the .done() / .fail() methods of jQuery.getJSON() .

 //first call var flickerAPI = "http://api.flickr.com/services/feeds/photos_public.gne?jsoncallback=?"; $.getJSON(flickerAPI, { tags: "mount rainier", tagmode: "any", format: "json" }) .done(function(data) { $('#log').append('got data in first call<br>'); }) .fail(function(jqxhr, textStatus, error) { $('#log').append('got error in first call<br>'); }); //second call $.getJSON("willFail.js", { name: "John", time: "2pm" }) .done(function(json) { $('#log').append('got data in second call<br>'); }) .fail(function(jqxhr, textStatus, error) { $('#log').append('got error in second call<br>'); }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <p id="log"></p>