func LogFetchResultLoadingError(res *FetchResult, w http.ResponseWriter, r *http.Request) {
// 404 and 502 Error already become logged in logger.go
if res.Content.HttpStatusCode() != 404 && res.Content.HttpStatusCode() != 502 {
logging.Application(r.Header).WithField("fetchResult", res).Errorf("error loading content from: %v", res.Def.URL)
}
res.Def.ErrHandler.Handle(res.Err, res.Content.HttpStatusCode(), w, r)
}
func (agg *CompositionHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// If we know the host but don't have the Host header [any more] then we
// set [or restore] the header, because why would You just remove it!?:
if (r.Host != "") && (r.Header.Get("Host") == "") {
r.Header.Set("Host", r.Host)
}
fetcher := agg.contentFetcherFactory(r)
if agg.handleEmptyFetcher(fetcher, w, r) {
return
}
// fetch all contents
results := fetcher.WaitForResults()
// Allow HEAD requests and disable composition of body fragments
if agg.handleHeadRequests(results, w, r) {
return
}
mergeContext := agg.contentMergerFactory(fetcher.MetaJSON())
for _, res := range results {
if res.Err == nil && res.Content != nil {
// Handle responses with 30x status code or with response bodies
if agg.handleNonMergeableResponses(res, w, r) {
return
}
mergeContext.AddContent(res.Content, res.Def.Priority)
} else if res.Def.Required {
LogFetchResultLoadingError(res, w, r)
return
} else {
logging.Application(r.Header).WithField("fetchResult", res).Warnf("optional content not loaded: %v", res.Def.URL)
}
}
status := agg.extractStatusCode(results, w, r)
agg.copyHeadersIfNeeded(results, w, r)
// Overwrite Content-Type to ensure, that the encoding is correct
w.Header().Set("Content-Type", "text/html; charset=utf-8")
html, err := agg.processHtml(mergeContext, w, r)
// Return if an error occured within the html aggregation
if err != nil {
agg.purgeCacheEntries(results)
return
}
w.Header().Set("Content-Length", strconv.Itoa(len(html)))
w.WriteHeader(status)
w.Write(html)
}
func (agg *CompositionHandler) processHtml(mergeContext ContentMerger, w http.ResponseWriter, r *http.Request) ([]byte, error) {
html, err := mergeContext.GetHtml()
if err != nil {
logging.Application(r.Header).Error(err.Error())
http.Error(w, "Internal Server Error: "+err.Error(), 500)
}
return html, err
}
func (agg *CompositionHandler) handleEmptyFetcher(fetcher FetchResultSupplier, w http.ResponseWriter, r *http.Request) bool {
if fetcher.Empty() {
w.WriteHeader(500)
w.Write([]byte("Internal server error"))
logging.Application(r.Header).Error("No fetchers available for composition, throwing error 500")
return true
}
return false
}