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Asked: 2026-06-08T20:14:05+00:00

I have this HTML code, which is invoking my javascript code. The code is

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I have this HTML code, which is invoking my javascript code. The code is for a gauge. In the javascript code, I am trying to access a SVG file, and modifying the needle (of the gauge) to display the desired value. The code is working fine. However, I do not wish to call onload(); and “object id” in HTML. I just want that as soon as my HTML file loads, javascript is invoked automatically. I do not want to call anything in html (no object id, no onload function) except headline in body tags. I tried various onload() methods, also tried this link
http://www.techrepublic.com/article/preloading-and-the-javascript-image-object/5214317
But not able to implement it. Any help would be highly appreciated.

PS : I tried my best to be as thorough in explaining the problem. However, please let me know if I am unclear somewhere.

This is Gauge.png image which is embedded in the svg code I have pasted below
https://sphotos-b.xx.fbcdn.net/hphotos-snc6/179594_10150982737360698_1827200234_n.jpg

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <g name="gauge" width="122px" height="127px">
        <image xlink:href="gauging.png" width="122" height="127"/>
    <circle id="led" cx="39" cy="76" r="5" style="fill: #999; stroke: none">
        <animateColor id="ledAnimation" attributeName="fill" attributeType="css" begin="0s" dur="1s"
        values="none;#f88;#f00;#f88;none;" repeatCount="0"/>
    </circle>
        <g id="needle" transform="rotate(0,62,62)">
            <circle cx="62" cy="62" r="4" style="fill: #c00; stroke: none"/>
            <rect transform="rotate(-130,62,62)" name="arrow"  x="58" y="38" width="8" height="24" style="fill: #c00; stroke: none"/>
            <polygon transform="rotate(-130,62,62)" points="58,39,66,39,62,30,58,39" style="fill: #c00; stroke: none"/>
        </g>
        <text id="value" x="51" y="98" focusable="false" editable="no" style="stroke:none; fill:#fff; font-family: monospace; font-size: 12px"></text>
    </g>
</svg>

HTML+ Javascript Code 

<head>
<title>SVG Gauge example</title>

<script>
function update1(){
    var scale=100;
    var value;
    var value1 = 69;

    var el=document.getElementById('gauge1');       
    if (!el) return;

    /* Get SVG document from HTML element */
    var svg_doc = el.contentDocument;
    if (!svg_doc) return;


    /* Rotate needle to display given value */
    var needle_el = svg_doc.getElementById('needle');
    if (!needle_el) return;
    /* Calc rotation angle (0->0%, 260->100%) */
    value = parseInt(value1);
    scale = parseInt(scale);
    if (value > scale) value = scale;
    var angle = value / scale * 260;
    /* On-the-fly SVG transform */
    needle_el.setAttribute('transform','rotate('+angle+',62,62)');
}
</script>

</head>
<body onload="update1(); ">
<div>
<object id="gauge1" type="image/svg+xml" data="gauge.svg" width="127" height="122"/>
</div>
</body>    

</html>
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1 Answer

  1. Editorial Team

    To avoid the onload attribute, you can use the load event:

    <script type="text/javascript">
    function update1() {
        // ...
    }

    document.addEventListener('load', update1, true);
</script>
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