// Given a request, follow the segments through sitetree to find the page that is being requested. Doesn't
// understand actions, so just finds the page. Returns ID of SiteTree_Live record or 0 if it can't find a
// matching page.
// @todo Understand BaseController actions, or break on the furthest it gets up the tree
// @todo cache site tree
func findPageToRender(r *http.Request) (int, error) {
siteCache := getSiteCache()
if siteCache != nil {
id, found := siteCache.findPageToRender(r)
if found {
// fmt.Printf("page cache hit %d\n", id)
return id, nil
}
}
s := strings.Trim(r.URL.Path, "/")
path := strings.Split(s, "/")
if len(path) == 0 || path[0] == "" {
// find a home page ID
r, e := orm.Query("select \"ID\" from \"SiteTree_Live\" where \"URLSegment\"='home' and \"ParentID\"=0")
defer r.Close()
if e != nil {
return 0, e
}
if !r.Next() {
return 0, nil
}
var ID int
e = r.Scan(&ID)
return ID, e
}
currParentID := 0
for _, p := range path {
r, e := orm.Query("select \"ID\",\"ParentID\" from \"SiteTree_Live\" where \"URLSegment\"='" + p + "' and \"ParentID\"=" + strconv.Itoa(currParentID))
defer r.Close()
if e != nil {
return 0, e
}
if !r.Next() {
return 0, nil
}
var ID, ParentID int
e = r.Scan(&ID, &ParentID)
currParentID = ID
}
// if we get to the end, we've found a matching ID in SiteTree_Live
return currParentID, nil
}
// primeSiteCache is responsible for re-computing the data structures in the cache. It does this
// by requerying the database, rebuilding the structure, and finally replacing the data structures
// atomically. In this way, a request being processed will either get the old version or the new
// version, but whichever version it's using won't be replaced mid-request.
func primeSiteCache() (*SiteCache, error) {
r, e := orm.Query(`select "ID","ClassName","ParentID","Title","MenuTitle","URLSegment" from "SiteTree_Live"`)
defer r.Close()
if e != nil {
fmt.Printf("ERROR EXECUTING SQL: %s\n", e)
return nil, e
}
newCache := newSiteCache()
for r.Next() {
e := newCache.ReadRow(r)
if e != nil {
return nil, e
}
}
newCache.derivePaths()
fmt.Printf("primeSiteCache: %s\n", newCache)
return newCache, nil
}