Input Card

This feature is only available in ESP-DASH Pro

The Input Card allows users to enter textual or numeric data. You can specify the type and precision.

Initializer

To create a input card in ESP-DASH v5, use the dash::InputCard<T, Precision> class. The template parameters allow you to control the value type and decimal precision:

• T: Value type (e.g., dash::string, int, float, const char*)
• Precision: Number of decimal places for floating point values (default: 2)

Example 1: String value (default)

dash::InputCard<dash::string> input(dashboard, "Input");

Example 2: Float value, custom precision (3 decimals)

dash::InputCard<float, 3> inputFloat(dashboard, "Enter float");

Example 3: Integer value

dash::InputCard<int> inputInt(dashboard, "Enter int");

Callback

Register a callback function to be called when the text changes:

input.onChange([](const char* newText) {
  // Handle text change
  Serial.printf("Text changed: %s\n", newText);
});

Methods

setValue(T value)

Set the input value. The type of value must match the template type you chose for T (e.g., dash::string, int, float, const char*).

input.setValue(value); // value is of type T

• Signature: void setValue(T value)
• Parameters:
  • T value — The value to set (type matches template parameter T).
• Returns: void

value()

Get the current input value. The return type matches your template type for T (e.g., dash::string, int, float, const char*).

T txt = input.value();

• Signature: T value()
• Parameters: None
• Returns: T — The current value (type matches template parameter T).

Note:

• T can be one of: dash::string, int, float, or const char* depending on how you instantiate the card.

Reference

Below is a reference code showing how to integrate this widget in a real project, including initialization and value updates usage.

// ...
 
// Create a input card (string, default)
dash::InputCard<dash::string> textCard(dashboard, "Input");
 
void setup() {
  // ...
  textCard.setValue("Hello");
}
 
void loop() {
  // ...
}