measureJsonPretty()
Description
Computes the length of the prettified JSON document that serializeJsonPretty() produces, excluding the null-terminator.
This function is handy to fill the Content-Length header of an HTTP message.
Signature
size_t measureJsonPretty(TSource src); Arguments
src: the value to serialize. It can be aJsonDocument,JsonArray,JsonArrayConst,JsonObject,JsonObjectConst,JsonVariant, orJsonVariantConst.
Return value
The number of characters that serializeJsonPretty()produces, excluding the null-terminator.
Example
// Send headers client.println("Content-Type: application/json"); client.print("Content-Length: "); client.println(measureJsonPretty(doc)); // Terminate headers client.println(); // Send body serializeJsonPretty(doc, client); 