From what I could find about the subject, you can use <script> tag in a text/html tiddler but the simple examples I seen shown (shown below) don't work in my TW-- I get the iframe but no content. Using single file TW 5.1.17 & 5.1.19 with latest Firefox.
<script type="text/javascript">
alert("Hooray");
</script>
<script type="text/javascript">
alert("hooray!\n\n"
+ "Your username is '"
+ window.parent.$tw.wiki.getTiddlerText("$:/status/UserName") + "'\n\n" +
+ "And this wiki is called '"
+ window.parent.$tw.wiki.getTiddlerText("$:/SiteTitle")+"'");
</script>
I'm using javascript (shown below) to manipulate an external svg to display with an <object> tag -- it works if I have it in an external html that I display in an iframe but won't work in a text/html tiddler. I'm probably dealing with multiple issues-- any hints would be greatly appreciated.
<object id="svg-object" data="stormsmuth.svg" type="image/svg+xml"></object>
<script type="text/javascript">
window.addEventListener("load", function() {
var svgObject = document.getElementById("svg-object").contentDocument;
var svg = svgObject.getElementById('stormslayers1');
svg.setAttribute("viewBox", "100 100 400 400");
var element = svgObject.getElementById("CITYLIMIT");
element.setAttribute("stroke", "#ee82ee");
element.setAttribute("stroke-width", "4px");
element.setAttribute("stroke-dasharray", "3 1 1 1 3");
var element2 = svgObject.getElementById("sectbord");
element2.setAttribute("stroke", "pink");
element2.setAttribute("stroke-width", "2px");
element2.setAttribute("stroke-dasharray", "2 2");
var element3 = svgObject.getElementById("sectname2");
element3.setAttribute("fill", "white");
console.log(svg);
});
</script>