From 1890024e57f623ceec744bb3a6922d89d2d47640 Mon Sep 17 00:00:00 2001
From: Toni Uhlig <matzeton@googlemail.com>
Date: Thu, 4 Jul 2019 00:03:51 +0200
Subject: very basic templating engine

---
 MemDriverWeb/MemDriverWeb.cpp             | 15 +++++++++++----
 MemDriverWeb/MemDriverWeb.vcxproj         |  1 +
 MemDriverWeb/MemDriverWeb.vcxproj.filters |  3 +++
 MemDriverWeb/minitmpl.cpp                 | 19 +++++++++++++++++++
 MemDriverWeb/minitmpl.h                   | 17 +++++++++--------
 MemDriverWeb/pch.h                        |  1 +
 MemDriverWeb/www.h                        |  7 +++----
 7 files changed, 47 insertions(+), 16 deletions(-)
 create mode 100644 MemDriverWeb/minitmpl.cpp

(limited to 'MemDriverWeb')

diff --git a/MemDriverWeb/MemDriverWeb.cpp b/MemDriverWeb/MemDriverWeb.cpp
index cf0e07e..5e9dfc5 100644
--- a/MemDriverWeb/MemDriverWeb.cpp
+++ b/MemDriverWeb/MemDriverWeb.cpp
@@ -9,21 +9,28 @@ using httplib::Response;
 
 static const char *host = "127.0.0.1";
 static const int port = 8080;
-static const std::string header = DEFAULT_HEADER;
-static const std::string footer = DEFAULT_FOOTER;
+static const std::string template_content = DEFAULT_TEMPLATE;
 
 static void page_root(const Request &req, Response &res)
 {
 	TemplateString ss;
 
-	ss << header << footer;
-	res.set_content(ss.str(), "text/html");
+	ss << template_content;
+	res.set_content(ss.doTemplateStr(), "text/html");
+}
+
+static std::string& template_test_cb(std::string &out)
+{
+	out.append("--- TEST ---");
+	return out;
 }
 
 int main()
 {
 	httplib::Server httpServer;
 
+	TemplateString::registerTemplateCallback("<% CONTENT %>", template_test_cb);
+
     std::cout << "Starting WebServer on " << host << ":" << port << "\n"; 
 	httpServer.Get("/", page_root);
 
diff --git a/MemDriverWeb/MemDriverWeb.vcxproj b/MemDriverWeb/MemDriverWeb.vcxproj
index 00d5a8b..a545fd4 100644
--- a/MemDriverWeb/MemDriverWeb.vcxproj
+++ b/MemDriverWeb/MemDriverWeb.vcxproj
@@ -162,6 +162,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="MemDriverWeb.cpp" />
+    <ClCompile Include="minitmpl.cpp" />
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">Create</PrecompiledHeader>
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Create</PrecompiledHeader>
diff --git a/MemDriverWeb/MemDriverWeb.vcxproj.filters b/MemDriverWeb/MemDriverWeb.vcxproj.filters
index 5874c87..040e7bd 100644
--- a/MemDriverWeb/MemDriverWeb.vcxproj.filters
+++ b/MemDriverWeb/MemDriverWeb.vcxproj.filters
@@ -35,5 +35,8 @@
     <ClCompile Include="MemDriverWeb.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="minitmpl.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/MemDriverWeb/minitmpl.cpp b/MemDriverWeb/minitmpl.cpp
new file mode 100644
index 0000000..3d7c34c
--- /dev/null
+++ b/MemDriverWeb/minitmpl.cpp
@@ -0,0 +1,19 @@
+#include "pch.h"
+#include "minitmpl.h"
+
+std::map<std::string, template_cb> TemplateString::template_callbacks;
+
+std::string TemplateString::doTemplateStr() {
+	size_t pos = 0;
+	in_cache = str();
+
+	out_cache.clear();
+	for (auto& key : template_callbacks) {
+		while ((pos = in_cache.find(key.first, pos)) != std::string::npos) {
+			in_cache.replace(pos, key.first.length(), key.second(out_cache));
+			pos += out_cache.length();
+		}
+	}
+
+	return in_cache;
+}
\ No newline at end of file
diff --git a/MemDriverWeb/minitmpl.h b/MemDriverWeb/minitmpl.h
index 446930a..426579c 100644
--- a/MemDriverWeb/minitmpl.h
+++ b/MemDriverWeb/minitmpl.h
@@ -1,17 +1,18 @@
 #pragma once
 
+#include <map>
 #include <sstream>
 
+typedef std::function<std::string&(std::string&)> template_cb;
+
 class TemplateString : public std::stringstream
 {
 public:
-	std::string& doTemplateStr(const std::string& search, const std::string& replace) {
-		size_t pos = 0;
-		std::string s = this->str();
-		while ((pos = s.find(search, pos)) != std::string::npos) {
-			s.replace(pos, search.length(), replace);
-			pos += replace.length();
-		}
-		return s;
+	static void registerTemplateCallback(const char *variable, template_cb cb) {
+		TemplateString::template_callbacks[std::string(variable)] = cb;
 	}
+	std::string doTemplateStr();
+private:
+	std::string in_cache, out_cache;
+	static std::map<std::string, template_cb> template_callbacks;
 };
\ No newline at end of file
diff --git a/MemDriverWeb/pch.h b/MemDriverWeb/pch.h
index a4977f6..314f3f7 100644
--- a/MemDriverWeb/pch.h
+++ b/MemDriverWeb/pch.h
@@ -2,5 +2,6 @@
 #define PCH_H
 
 #include "httplib.h"
+#include "minitmpl.h"
 
 #endif //PCH_H
diff --git a/MemDriverWeb/www.h b/MemDriverWeb/www.h
index 79c1116..48d2fbb 100644
--- a/MemDriverWeb/www.h
+++ b/MemDriverWeb/www.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#define DEFAULT_HEADER \
+#define DEFAULT_TEMPLATE \
 "<!DOCTYPE html>\n<html lang = \"en\">\n<head>\n" \
 "<title>Bootstrap Example</title>\n" \
 "<meta charset = \"utf-8\"><meta name = \"viewport\" content = \"width=device-width, initial-scale=1\">\n" \
@@ -17,7 +17,6 @@
 "</li>\n<li class = \"nav-item\">\n" \
 "<a class = \"nav-link\" href = \"#\">Link 3 </a>\n" \
 "</li>\n</ul>\n</nav>\n<br>\n\n" \
-"<div class = \"container-fluid\">\n\n";
-
-#define DEFAULT_FOOTER \
+"<div class = \"container-fluid\">\n\n" \
+"<% CONTENT %>\n\n" \
 "</div>\n\n</body>\n</html>\n\n";
\ No newline at end of file
-- 
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