Add BB-code parser.

bbcode/bbcode.js

+let el = document.getElementsByClassName("nfo")[0].children[0]
+let str = el.innerText
+
+var r = /\[(\/)?(\w{0,5})(=([^\]]*))?\]/g
+
+let result;
+let stk = [];
+
+let result_str = "";
+let last_idx = 0;
+
+let other;
+
+while ((result = r.exec(str)) !== null) {
+    index = result.index
+    var [matched, end, tag, _, param] = result
+    if (! end) { /* if start tag */
+        o = Object()
+        o.tag = tag
+        o.str = ""
+        o.index = index + matched.length
+        o.param = param
+        if (stk.length === 0) {
+            result_str += str.substring(last_idx, index);
+        } else {
+            other = stk.last();
+            other.str += str.substring(other.index, index);
+        }
+        last_idx = o.index;
+        stk.push(o)
+
+    } else { /* if end tag */
+        parent = stk.pop()
+        if (parent.tag !== tag) {
+            alert("Non matching tags");
+        } else {
+            parent.str += str.substring(last_idx, index);
+            parent.str = parent.str.strip()
+            last_idx = index + matched.length;
+            var s;
+            switch (parent.tag) {
+            case "url":
+                if (typeof parent.param === "undefined") {
+                    s = "<a href='" + parent.str;
+                } else {
+                    s = "<a href='" + parent.param;
+                }
+                s += "'>" + parent.str + "</a>";
+                break;
+
+            case "img":
+                s = "<img src='" + parent.str + "'/>"
+                break;
+
+            default:
+                s = "<b>Unknown tag <pre>" + parent.str + "</pre></b>"
+                break;
+            }
+            if (stk.length === 0) {
+                result_str += s;
+            } else {
+                stk.last().str += s;
+            }
+        }
+    }
+}
+
+el.innerHTML = result_str