add getURL and originalBase logic to content from pages

content/url_js.go

@@ -8,9 +8,12 @@ package content
 
 import (
 	"fmt"
+	"net/url"
 	"syscall/js"
 )
 
+var documentData = js.Global().Get("document").Get("documentElement").Get("dataset")
+
 // saveWebURL saves the current page URL to the user's address bar and history.
 func (ct *Content) saveWebURL() {
 	url := ct.currentPage.URL
@@ -23,8 +26,44 @@ func (ct *Content) saveWebURL() {
 // handleWebPopState adds a JS event listener to handle user navigation in the browser.
 func (ct *Content) handleWebPopState() {
 	js.Global().Get("window").Call("addEventListener", "popstate", js.FuncOf(func(this js.Value, args []js.Value) any {
-		url := js.Global().Get("location").Get("href").String()
-		fmt.Println(url)
+		full, base, err := getURL()
+		fmt.Println(full, base, err)
 		return nil
 	}))
 }
+
+// originalBase is used to cache the first website base URL to prevent
+// issues with invalidation of the base URL caused by the data-base-path
+// attribute not updating when a new page is loaded (because it is a
+// Single-Page Application (SPA) so it doesn't load anything new).
+var originalBase *url.URL
+
+// getURL returns the full current URL and website base URL.
+func getURL() (full, base *url.URL, err error) {
+	full, err = url.Parse(js.Global().Get("location").Get("href").String())
+	if err != nil {
+		return
+	}
+	if originalBase != nil {
+		base = originalBase
+		return
+	}
+	basePath, err := url.Parse(documentData.Get("basePath").String())
+	if err != nil {
+		return
+	}
+	base = full.ResolveReference(basePath)
+	originalBase = base
+
+	// We must apply our new absolute base path to all of the links so
+	// that the favicon updates correctly on future page changes.
+	documentData.Set("basePath", base.String())
+	links := js.Global().Get("document").Get("head").Call("getElementsByTagName", "link")
+	for i := range links.Length() {
+		link := links.Index(i)
+		// Get returns the absolute version, so we can just call Set with it
+		// to update the href to actually be the absolute version.
+		link.Set("href", link.Get("href").String())
+	}
+	return
+}