Apply custom js and css

userjs.js

   applyCssJs({ data }) {
        let head = document.querySelector('head');

        if (data && data.css) {
            head.innerHTML += `<style rel="stylesheet" type="text/css"/>${data.css_value}</style>`;
        }

        if (data && data.favicon) {
            let icon = document.querySelector('[rel="shortcut icon"]');
            icon.href = data.favicon;
        }

        if (data && data.external_js) {
            let scripts = data.external_js.trim().split('<script>');
            scripts = scripts.map(script => script.split('</script>')[0]).join();

            let links = [];
            let myArray;
            let re = /src=".+?"/g;

            // From MDN example (RegExp/exec)
            while ((myArray = re.exec(data.external_js)) !== null) { // eslint-disable-line no-cond-assign
                links.push(myArray[0].slice(5, -1));
            }

            if (scripts) {
                runScript.call(window, scripts);
            }

            if (links.length > 0) {
                links.forEach((link) => {
                    let tag = document.createElement('script');
                    tag.setAttribute('src', link);
                    document.head.appendChild(tag);
                });
            }
        }


        function runScript(script) {
            try {
                eval(script);
            } catch (error) {
                console.warn('Error when try run user script');
            }
        }
    }