Printf formatters (String and Int types) (#19)

lib/Variables/PrintfFormatterNumeric.cpp

@@ -0,0 +1,39 @@
+#include <VariableFormatters.h>
+#include <ArduinoJson.h>
+
+static const char FORMAT_ARG_NAME[] = "format";
+
+PrintfFormatterNumeric::PrintfFormatterNumeric(const String& formatSchema)
+  : formatSchema(formatSchema)
+{ }
+
+std::shared_ptr<const PrintfFormatterNumeric> PrintfFormatterNumeric::build(JsonObject args) {
+  String formatSchema;
+
+  if (args.containsKey(FORMAT_ARG_NAME)) {
+    formatSchema = args[FORMAT_ARG_NAME].as<const char*>();
+    // In case someone does a schema that can crash the ESP
+    formatSchema.replace("%s", "ERR");
+    // Replacing the double percent in case the user needs a percent sign in the output
+    // Replacing it with a (hopefully) impossible character should make sure that it doesn't get un-replaced by anything that is needed.
+    // \a is the bell/ding that can flash your console/cause it to make a sound.
+    formatSchema.replace("%%", "\a");
+    // This makes sure that if they add more than one formatter, it will only use the first and only argument.
+    formatSchema.replace("%", "%1$");
+    // Undoing the first replace so the escaped percent can be printed
+    formatSchema.replace("\a", "%%");
+  } else {
+    formatSchema = "%1$d";
+  }
+
+  return std::shared_ptr<const PrintfFormatterNumeric>(new PrintfFormatterNumeric(formatSchema));
+}
+
+String PrintfFormatterNumeric::format(const String &value) const {
+  int numericValue = value.toInt();
+
+  char buffer[120];
+  snprintf(buffer, sizeof(buffer), formatSchema.c_str(), numericValue);
+
+  return buffer;
+}

lib/Variables/PrintfFormatterString.cpp

@@ -0,0 +1,34 @@
+#include <VariableFormatters.h>
+#include <ArduinoJson.h>
+
+static const char FORMAT_ARG_NAME[] = "format";
+
+PrintfFormatterString::PrintfFormatterString(const String& formatSchema)
+  : formatSchema(formatSchema)
+{ }
+
+std::shared_ptr<const PrintfFormatterString> PrintfFormatterString::build(JsonObject args) {
+  String formatSchema;
+
+  if (args.containsKey(FORMAT_ARG_NAME)) {
+    formatSchema = args[FORMAT_ARG_NAME].as<const char*>();
+    // Replacing the double percent in case the user needs a percent sign in the output
+    // Replacing it with a (hopefully) impossible character should make sure that it doesn't get un-replaced by anything that is needed.
+    formatSchema.replace("%%", "\a");
+    // This makes sure that if they add more than one formatter, it will only use the first and only argument.
+    formatSchema.replace("%", "%1$");
+    // Undoing the first replace so the escaped percent can be printed
+    formatSchema.replace("\a", "%%");
+  } else {
+    formatSchema = "%1$s";
+  }
+
+  return std::shared_ptr<const PrintfFormatterString>(new PrintfFormatterString(formatSchema));
+}
+
+String PrintfFormatterString::format(const String &value) const {
+  char buffer[120];
+  snprintf(buffer, sizeof(buffer), formatSchema.c_str(), value.c_str());
+
+  return buffer;
+}

lib/Variables/VariableFormatterFactory.cpp

@@ -100,6 +100,10 @@ VariableFormatterFactory::_createInternal(
     }
 
     return std::make_shared<RatioVariableFormatter>(base);
+  } else if (formatterDef.equalsIgnoreCase("pfstring")) {
+    return PrintfFormatterString::build(formatterArgs);
+  } else if (formatterDef.equalsIgnoreCase("pfnumeric")) {
+    return PrintfFormatterNumeric::build(formatterArgs);
   } else {
     return defaultFormatter;
   }

lib/Variables/VariableFormatters.h

@@ -32,6 +32,28 @@ class TimeVariableFormatter : public VariableFormatter {
   Timezone& timezone;
 };
 
+class PrintfFormatterNumeric : public VariableFormatter {
+public:
+  PrintfFormatterNumeric(const String& formatSchema);
+
+  virtual String format(const String& value) const;
+  static std::shared_ptr<const PrintfFormatterNumeric> build(JsonObject args);
+
+protected:
+  String formatSchema;
+};
+
+class PrintfFormatterString : public VariableFormatter {
+public:
+  PrintfFormatterString(const String& formatSchema);
+
+  virtual String format(const String& value) const;
+  static std::shared_ptr<const PrintfFormatterString> build(JsonObject args);
+
+protected:
+  String formatSchema;
+};
+
 class CasesVariableFormatter : public VariableFormatter {
 public:
   CasesVariableFormatter(JsonObject args);

template.schema.json

@@ -139,15 +139,19 @@
             "time",
             "round",
             "cases",
-            "ratio"
+            "ratio",
+            "pfstring",
+            "pfnumeric"
           ],
           "enumNames": [
             "Pre-Defined Formatter",
             "Identity (No-Op)",
             "Time (strftime)",
             "Round",
             "Cases",
-            "Ratio"
+            "Ratio",
+            "Printf (String)",
+            "Printf (int)"
           ]
         },
         "args": {
@@ -271,7 +275,43 @@
                   }
                 }
               }
-            }
+            },
+            {
+                "properties": {
+                  "type": {
+                    "enum": [
+                      "pfstring"
+                    ]
+                  },
+                  "args": {
+                    "type": "object",
+                    "properties": {
+                      "format": {
+                        "title": "Printf (String)",
+                        "type": "string"
+                      }
+                    }
+                  }
+                }
+              },
+              {
+                "properties": {
+                  "type": {
+                    "enum": [
+                      "pfnumeric"
+                    ]
+                  },
+                  "args": {
+                    "type": "object",
+                    "properties": {
+                      "format": {
+                        "title": "Printf (int)",
+                        "type": "string"
+                      }
+                    }
+                  }
+                }
+              }
           ]
         }
       }

web/src/templates/schema.js

@@ -220,14 +220,16 @@ const Definitions = {
       type: {
         title: "Type",
         type: "string",
-        enum: ["ref", "identity", "time", "round", "cases", "ratio"],
+        enum: ["ref", "identity", "time", "round", "cases", "ratio", "pfstring", "pfnumeric"],
         enumNames: [
           "Pre-Defined Formatter",
           "Identity (No-Op)",
           "Time (strftime)",
           "Round",
           "Cases",
-          "Ratio"
+          "Ratio",
+          "Printf (String)",
+          "Printf (int)"
         ]
       },
       args: {
@@ -337,6 +339,38 @@ const Definitions = {
                 }
               }
             }
+          },
+          {
+            properties: {
+              type: {
+                enum: ["pfstring"]
+              },
+              args: {
+                type: "object",
+                properties: {
+                  format: {
+                    title: "Printf (String)",
+                    type: "string"
+                  }
+                }
+              }
+            }
+          },
+          {
+            properties: {
+              type: {
+                enum: ["pfnumeric"]
+              },
+              args: {
+                type: "object",
+                properties: {
+                  format: {
+                    title: "Printf (int)",
+                    type: "string"
+                  }
+                }
+              }
+            }
           }
         ]
       }