From 7ec2e01e435cef52a7e8b7d2a6df147e0d6c3f1d Mon Sep 17 00:00:00 2001
From: Captain ALM <captainalm@captainalm.com>
Date: Fri, 15 Jul 2022 13:28:29 +0100
Subject: [PATCH] Add the ability to toggle filtering URL parameters passed to
 page providers.

---
 conf/serve.go               |  9 +++++----
 config.example.yml          | 13 +++++++++++++
 pageHandler/page-handler.go | 19 ++++++++++++++-----
 3 files changed, 32 insertions(+), 9 deletions(-)
 create mode 100644 config.example.yml

diff --git a/conf/serve.go b/conf/serve.go
index 19fb367..96a4125 100644
--- a/conf/serve.go
+++ b/conf/serve.go
@@ -1,8 +1,9 @@
 package conf
 
 type ServeYaml struct {
-	DataStorage    string            `yaml:"dataStorage"`
-	Domains        []string          `yaml:"domains"`
-	RangeSupported bool              `yaml:"rangeSupported"`
-	CacheSettings  CacheSettingsYaml `yaml:"cacheSettings"`
+	DataStorage      string            `yaml:"dataStorage"`
+	Domains          []string          `yaml:"domains"`
+	RangeSupported   bool              `yaml:"rangeSupported"`
+	FilterURLQueries bool              `yaml:"filterURLQueries"`
+	CacheSettings    CacheSettingsYaml `yaml:"cacheSettings"`
 }
diff --git a/config.example.yml b/config.example.yml
new file mode 100644
index 0000000..a8afee8
--- /dev/null
+++ b/config.example.yml
@@ -0,0 +1,13 @@
+listen:
+  webNetwork: "tcp4"
+  web: ":8080"
+  webMethod: "http"
+  identify: true
+serve:
+  rangeSupported: true
+  cacheSettings:
+    enableContentsCaching: true
+    enableContentsCachePurge: true
+    maxAge: 3600
+    notModifiedUsingLastModified: true
+    notModifiedUsingETags: true
\ No newline at end of file
diff --git a/pageHandler/page-handler.go b/pageHandler/page-handler.go
index bcc764b..58726a4 100644
--- a/pageHandler/page-handler.go
+++ b/pageHandler/page-handler.go
@@ -19,6 +19,7 @@ type PageHandler struct {
 	PageProviders            map[string]PageProvider
 	pageContentsCacheRWMutex *sync.RWMutex
 	RangeSupported           bool
+	FilterURLQueries         bool
 	CacheSettings            conf.CacheSettingsYaml
 }
 
@@ -40,6 +41,7 @@ func NewPageHandler(config conf.ServeYaml) *PageHandler {
 		PageProviders:            GetProviders(config.CacheSettings.EnableTemplateCaching, config.DataStorage),
 		pageContentsCacheRWMutex: theMutex,
 		RangeSupported:           config.RangeSupported,
+		FilterURLQueries:         config.FilterURLQueries,
 		CacheSettings:            config.CacheSettings,
 	}
 }
@@ -162,7 +164,10 @@ func (ph *PageHandler) GetCleanQuery(request *http.Request) (url.Values, string)
 		return make(url.Values), ""
 	}
 	supportedKeys := provider.GetSupportedURLParameters()
-	toDelete := make([]string, len(toClean))
+	var toDelete []string
+	if ph.FilterURLQueries {
+		toDelete = make([]string, len(toClean))
+	}
 	theSize := 0
 	theQuery := ""
 	for s, v := range toClean {
@@ -174,8 +179,10 @@ func (ph *PageHandler) GetCleanQuery(request *http.Request) (url.Values, string)
 			}
 		}
 		if noExist {
-			toDelete[theSize] = s
-			theSize++
+			if ph.FilterURLQueries {
+				toDelete[theSize] = s
+				theSize++
+			}
 		} else {
 			for _, i := range v {
 				if i == "" {
@@ -186,8 +193,10 @@ func (ph *PageHandler) GetCleanQuery(request *http.Request) (url.Values, string)
 			}
 		}
 	}
-	for i := 0; i < theSize; i++ {
-		delete(toClean, toDelete[i])
+	if ph.FilterURLQueries {
+		for i := 0; i < theSize; i++ {
+			delete(toClean, toDelete[i])
+		}
 	}
 	return toClean, strings.TrimRight(theQuery, "&")
 }