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(const JsonDocument& doc);
Arguments
doc: the JsonDocument to serialize (in fact, you can also use a JsonArray, a JsonObject, or a JsonVariant).
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);
