I've been reading the NodeMCU documentation and several closed issues about the change of SDK that previouly allowed to send multiple data streams (acting like a queued net.socket:send).
It seems a huge debate grew here (#730) and there (#993) or even here (#999). However, I did not find any convincing example of a webserver code that would allow me to read multiple html files (e.g. head.html and body.html) to display a page. Here's the example from TerryE that I tried to adapt, but with no success:
srv=net.createServer(net.TCP)
srv:listen(80,function(conn)
conn:on ("receive", function(sck, req)
local response = {}
local f = file.open("head.html","r")
if f ~= nil then
response[#response+1] = file.read()
file.close()
end
local f = file.open("body.html","r")
if f ~= nil then
response[#response+1] = file.read()
file.close()
end
local function sender (sck)
if #response>0 then sck:send(table.remove(response,1))
else sck:close()
end
end
sck:on("sent", sender)
sender(sck)
end )
end )
When connecting to the ESP8266, nothing loads and I get no error from the lua terminal.
For your information, head.html contains:
<html>
<head>
</head>
And body.html contains:
<body>
<h1>Hello World</h1>
</body>
</html>
I am very new to NodeMCU, please be tolerant.
Here is my solution without using tables, saving some memory:
function Sendfile(sck, filename, sentCallback)
if not file.open(filename, "r") then
sck:close()
return
end
local function sendChunk()
local line = file.read(512)
if line then
sck:send(line, sendChunk)
else
file.close()
collectgarbage()
if sentCallback then
sentCallback()
else
sck:close()
end
end
end
sendChunk()
end
srv = net.createServer(net.TCP)
srv:listen(80, function(conn)
conn:on("receive", function(sck, req)
sck:send("HTTP/1.1 200 OK\r\n" ..
"Server: NodeMCU on ESP8266\r\n" ..
"Content-Type: text/html; charset=UTF-8\r\n\r\n",
function()
Sendfile(sck, "head.html", function() Sendfile(sck, "body.html") end)
end)
end)
end)
And this is for serving single files:
function Sendfile(client, filename)
if file.open(filename, "r") then
local function sendChunk()
local line = file.read(512)
if line then
client:send(line, sendChunk)
else
file.close()
client:close()
collectgarbage()
end
end
client:send("HTTP/1.1 200 OK\r\n" ..
"Server: NodeMCU on ESP8266\r\n" ..
"Content-Type: text/html; charset=UTF-8\r\n\r\n", sendChunk)
else
client:send("HTTP/1.0 404 Not Found\r\n\r\nPage not found")
client:close()
end
end
srv = net.createServer(net.TCP)
srv:listen(80, function(conn)
conn:on ("receive", function(client, request)
local path = string.match(request, "GET /(.+) HTTP")
if path == "" then path = "index.htm" end
Sendfile(client, path)
end)
end)
Thank you for the reply. I actually added the header you mentioned, I didn't know that was necessary and I also removed the sck argument in the sender function. My first code was actually working, I don't know what was wrong last time.
Anyway, it helped me understanding what was happening: the following code seems to concatenate the response array, since the event sent of the socket calls back the sender function (sck:on("sent", sender))
sck:send(table.remove(response,1))
In fact, table.remove(array, 1) returns the first item of the array, and removes this item of the array. Calling this line multiple times has the effect to read through it, item by item.
For the sake of simplicity, here is the code of a simple webserver able to serve multiple files:
header = "HTTP/1.0 200 OK\r\nServer: NodeMCU on ESP8266\r\nContent-Type: text/html\r\n\r\n"
srv=net.createServer(net.TCP)
srv:listen(80,function(conn)
conn:on ("receive", function(sck, req)
local response = {header}
tgtfile = string.sub(req,string.find(req,"GET /") +5,string.find(req,"HTTP/") -2 )
if tgtfile == "" then tgtfile = "index.htm" end
local f = file.open(tgtfile,"r")
if f ~= nil then
response[#response+1] = file.read()
file.close()
else
response[#response+1] = "<html>"
response[#response+1] = tgtfile.." not Found - 404 error."
response[#response+1] = "<a href='index.htm'>Home</a>"
end
collectgarbage()
f = nil
tgtfile = nil
local function sender ()
if #response>0 then sck:send(table.remove(response,1))
else sck:close()
end
end
sck:on("sent", sender)
sender()
end)
end)
This example was taken from this instructables and fixed to work with the new SDK (which do not allow multiple :send anymore). Please let me know if this code has some issues.
I don't know what is the size limit of the files though. Nevertheless, I manage to append more than 2Ko to the response variable and send it at once without any issue.
