Fix svelte template replace would recursively replace

src/frontend/SvelteViewEngine.ts

@@ -62,7 +62,7 @@ export default class SvelteViewEngine extends ViewEngine {
 
         // Root template
         const templateFile = await this.resolveFileFromCanonicalName('layouts/svelte_layout.html');
-        let output = await this.fileCache.get(templateFile, !config.get<boolean>('view.cache'));
+        const rawOutput = await this.fileCache.get(templateFile, !config.get<boolean>('view.cache'));
 
         // Pre-compiled parts
         const [
@@ -97,11 +97,40 @@ export default class SvelteViewEngine extends ViewEngine {
         const props = JSON.stringify(localMap);
 
         // Replaces
-        output = output.replace('%canonicalViewName%', canonicalViewName);
-        output = output.replace('%props%', props);
-        output = output.replace('%head%', head);
-        output = output.replace('%html%', html);
-        output = output.replace('%css%', css);
+        const replaces: { [key: string]: string } = {
+            canonicalViewName: canonicalViewName,
+            props: props,
+            head: head,
+            html: html,
+            css: css,
+        };
+        const replaceOperations: Record<number, {
+            key: string;
+            replaceValue: string;
+        } | undefined> = {};
+        for (const entry of Object.entries(replaces)) {
+            const matches = rawOutput.matchAll(new RegExp(`%${entry[0]}%`, 'g'));
+            for (const match of matches) {
+                if (typeof match.index === 'number') {
+                    replaceOperations[match.index] = {
+                        key: `%${entry[0]}%`,
+                        replaceValue: entry[1],
+                    };
+                }
+            }
+        }
+
+
+        let output = '';
+        for (let i = 0; i < rawOutput.length; i++) {
+            const replaceOperation = replaceOperations[i];
+            if (replaceOperation) {
+                output += replaceOperation.replaceValue;
+                i += replaceOperation.key.length - 1;
+            } else {
+                output += rawOutput[i];
+            }
+        }
 
         callback(null, output);
     }