Adds AutoConnectInput::isValid function

examples/mqttRSSI/mqttRSSI.ino

@@ -292,8 +292,9 @@ String saveParams(AutoConnectAux& aux, PageArgument& args) {
 
   // Echo back saved parameters to AutoConnectAux page.
   AutoConnectText&  echo = aux.getElement<AutoConnectText>("parameters");
-  echo.value = "Server: " + serverName + "<br>";
-  echo.value += "Channel ID: " + channelId + "<br>";
+  echo.value = "Server: " + serverName;
+  echo.value += mqttserver.isValid() ? String(" (OK)") : String(" (ERR)");
+  echo.value += "<br>" + "Channel ID: " + channelId + "<br>";
   echo.value += "User Key: " + userKey + "<br>";
   echo.value += "API Key: " + apiKey + "<br>";
   echo.value += "Update period: " + String(updateInterval / 1000) + " sec.<br>";

keywords.txt

@@ -30,6 +30,7 @@ handleClient	KEYWORD2
 handleRequest	KEYWORD2
 home	KEYWORD2
 host	KEYWORD2
+isValid	KEYWORD2
 join	KEYWORD2
 load	KEYWORD2
 loadElement	KEYWORD2

src/AutoConnectElementBasis.h

@@ -105,6 +105,7 @@ class AutoConnectInputBasis : virtual public AutoConnectElementBasis {
   }
   virtual ~AutoConnectInputBasis() {}
   const String  toHTML(void) const override;
+  bool  isValid(void) const;
 
   String  label;      /**< A label for a subsequent input box */
   String  pattern;    /**< Format pattern to aid validation of input value */

src/AutoConnectElementBasisImpl.h

@@ -11,6 +11,7 @@
 #define _AUTOCONNECTELEMENTBASISIMPL_H_
 
 #include "AutoConnectElementBasis.h"
+#include <regex.h>
 
 /**
  * Generate an HTML <button> element. The onclick behavior depends on
@@ -66,6 +67,29 @@ const String AutoConnectInputBasis::toHTML(void) const {
   return html;
 }
 
+/**
+ * Evaluate the pattern as a regexp and return whether value matches.
+ * Always return true if the pattern is undefined.
+ * @return true  The value matches a pattern.
+ * @return false The value does not match a pattern.
+ */
+bool AutoConnectInputBasis::isValid(void) const {
+  regex_t preg;
+  bool  rc = true;
+  if (pattern.length()) {
+    if (regcomp(&preg, pattern.c_str(), REG_EXTENDED) != 0) {
+      AC_DEBUG("%s regex compile failed\n", pattern.c_str());
+      rc = false;
+    }
+    else {
+      regmatch_t  p_match[1];
+      rc = regexec(&preg, value.c_str(), 1, p_match, 0) == 0 ? true : false;
+      regfree(&preg);
+    }
+  }
+  return rc;
+}
+
 /**
 * Indicate an entry with the specified value in the value's collection.
 * @param value     The value to indicates in the collection.