Efl.Ui.Format: add string format checking for user input

src/lib/efl/interfaces/efl_ui_format.c

@@ -1,16 +1,92 @@
 #include "config.h"
 #include "Efl.h"
 
+#define ERR(...) EINA_LOG_DOM_ERR(EINA_LOG_DOMAIN_DEFAULT, __VA_ARGS__)
+
 typedef struct
 {
    const char *template;
 } Efl_Ui_Format_Data;
 
+static Eina_Bool
+_is_valid_digit(char x)
+{
+   return ((x >= '0' && x <= '9') || (x == '.')) ? EINA_TRUE : EINA_FALSE;
+}
+
+static int
+_format_string_check(const char *fmt)
+{
+   const char *itr = NULL;
+   const char *start = NULL;
+   Eina_Bool found = EINA_FALSE;
+   int ret_type = 0;
+
+   start = strchr(fmt, '%');
+   if (!start) return 0;
+
+   while (start)
+     {
+        if (found && start[1] != '%')
+          {
+             return 0;
+          }
+
+        if (start[1] != '%' && !found)
+          {
+             found = EINA_TRUE;
+             for (itr = start + 1; *itr != '\0'; itr++)
+               {
+                  if ((*itr == 'd') || (*itr == 'u') || (*itr == 'i') ||
+                      (*itr == 'o') || (*itr == 'x') || (*itr == 'X'))
+                    {
+                       ret_type = 1; //int
+                       break;
+                    }
+                  else if ((*itr == 'f') || (*itr == 'F'))
+                    {
+                       ret_type = 2; //double
+                       break;
+                    }
+                  else if (_is_valid_digit(*itr))
+                    {
+                       continue;
+                    }
+                  else
+                    {
+                       return 0;
+                    }
+               }
+          }
+        start = strchr(start + 2, '%');
+     }
+
+   return ret_type;
+}
+
 static void
 _default_format_cb(void *data, Eina_Strbuf *str, const Eina_Value value)
 {
    const Eina_Value_Type *type = eina_value_type_get(&value);
    Efl_Ui_Format_Data *sd = data;
+   int format_check_result;
+
+   if (type == EINA_VALUE_TYPE_TM)
+     {
+        struct tm v;
+        eina_value_get(&value, &v);
+        eina_strbuf_append_strftime(str, sd->template, &v);
+
+        return;
+     }
+
+   format_check_result = _format_string_check(sd->template);
+
+   if (format_check_result == 0)
+     {
+        ERR("Wrong String Format: %s\n", sd->template);
+        return;
+     }
 
    if (type == EINA_VALUE_TYPE_DOUBLE)
      {