Added form.c

35bd2b60 · Sergey Lyubka · c5287b90 · 35bd2b60 · 35bd2b60
Commit 35bd2b60 authored Apr 10, 2014 by Sergey Lyubka
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Makefile examples/Makefile +3 -0

form.c examples/form.c +81 -0

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--- a/examples/Makefile
+++ b/examples/Makefile
@@ -50,6 +50,9 @@ upload: upload.c ../mongoose.c
 auth: auth.c ../mongoose.c
 	$(CC) auth.c ../mongoose.c $(OUT) $(CFLAGS)

+form: form.c ../mongoose.c
+	$(CC) form.c ../mongoose.c $(OUT) $(CFLAGS)
+
 mjpg: mjpg.c ../mongoose.c
 	$(CC) mjpg.c ../mongoose.c $(OUT) $(CFLAGS)


--- a/examples/form.c
+++ b/examples/form.c
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include "mongoose.h"
+
+static int static_value = 123;  // Exposed and changeable via the form
+
+static void print_html_form(struct mg_connection *conn) {
+  mg_send_header(conn, "Content-Type", "text/html");
+  mg_send_header(conn, "Cache-Control", "max-age=0, post-check=0, "
+                 "pre-check=0, no-store, no-cache, must-revalidate");
+
+  // Note that all the following normally should reside in static HTML page
+  mg_printf_data(conn, "%s", "<html><head>");
+  // It is better to use local copy though
+  mg_printf_data(conn, "<script src=\"%s\"></script>",
+                 "http://code.jquery.com/jquery-1.11.0.min.js");
+  mg_printf_data(conn, "%s", "<script> jQuery(function() {\n");
+  // Here is the ajax call that fetches data from the device and
+  // updates the form
+  mg_printf_data(conn, "%s", "$.ajax({ url: '/get_value', dataType: 'json', "
+                 "success: function(d) { $('#val').val(d.value); }});\n");
+  // This ajax call is triggered when submit button is pressed. It sends new
+  // value to the device.
+  mg_printf_data(conn, "%s", "$(document).on('click', '#button', function() {"
+                 "  $.ajax({ url: '/set_value', dataType: 'json', "
+                 "  data: { new_value: $('#val').val() } });\n"
+                 "  return false; });\n");
+  mg_printf_data(conn, "%s", "});</script>");
+  mg_printf_data(conn, "%s", "</head><body>");
+  mg_printf_data(conn, "%s", "<h1>Ajax form submission example</h1>");
+  mg_printf_data(conn, "%s", "<form>");
+  mg_printf_data(conn, "%s", "Device value: <input type=text id=val />");
+  mg_printf_data(conn, "%s", "<input type=submit id=button />");
+  mg_printf_data(conn, "%s", "</form>");
+  mg_printf_data(conn, "%s", "</body></html>");
+}
+
+static int ev_handler(struct mg_connection *conn, enum mg_event ev) {
+  if (ev == MG_REQUEST) {
+    if (strcmp(conn->uri, "/get_value") == 0) {
+      mg_printf_data(conn, "{\"value\": %d}", static_value);
+    } else if (strcmp(conn->uri, "/set_value") == 0) {
+      // This Ajax endpoint sets the new value for the device variable
+      char buf[100] = "";
+      mg_get_var(conn, "new_value", buf, sizeof(buf));  // Get form variable
+      static_value = atoi(buf);                         // Set new value
+      mg_printf_data(conn, "%s", "{\"success\": true}");
+      printf("Setting value to [%d]\n", static_value);  // Debug trace
+    } else {
+      // Better way is to set "document_root" option, put "index.html" file
+      // into document_root and return MG_FALSE here. We're printing HTML
+      // page by hands just to keep everything in one C file.
+      print_html_form(conn);
+    }
+    return MG_TRUE;
+  } else if (ev == MG_AUTH) {
+    return MG_TRUE;
+  }
+
+  return MG_FALSE;
+}
+
+int main(void) {
+  struct mg_server *server;
+
+  // Create and configure the server
+  server = mg_create_server(NULL, ev_handler);
+  mg_set_option(server, "listening_port", "8000");
+
+  // Serve request. Hit Ctrl-C to terminate the program
+  printf("Starting on port %s\n", mg_get_option(server, "listening_port"));
+  for (;;) {
+    mg_poll_server(server, 1000);
+  }
+
+  // Cleanup, and free server instance
+  mg_destroy_server(&server);
+
+  return 0;
+}