MQX Software Solutions中的主题 MQX 4.1 HTTPSRV: How to modify the reponse header?

MQX 4.1 HTTPSRV: How to modify the reponse header?

pbanta — Fri, 10 Oct 2014 20:52:13 GMT

I'm working on updating a project from MQX 3.8.1 to MQX 4.1. The most major change is the new HTTPSRV API and the associated changes. With the old HTTPD server I was able to modify the response header like so:

/* Send the reply */
session->response.contenttype = CONTENT_TYPE_HTML;
session->response.statuscode = 302;
strncat(session->response.header, "Location: control.html\n", HTTPDCFG_MAX_HEADER_LEN);
httpd_sendhdr(session, 0, 0);

How can do the same with MQX 4.1? session->response no longer has a header field.

Thanks,

Paul

Re: MQX 4.1 HTTPSRV: How to modify the reponse header?

karelm_ — Mon, 13 Oct 2014 08:44:20 GMT

Hi Paul,

it is no longer possible to modify a header of HTTP response directly. However in your case you can use a redirection in HTML using the http-equip attribute of the <meta> tag (see HTML meta http-equiv Attribute). And compose response using this tag in your CGI. Here is an example:

response.content_type = HTTPSRV_CONTENT_TYPE_HTML;
response.data = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\">"
"<html><head><title>My Title</title>"
"<meta http-equiv=\"REFRESH\" content=\"0;url=my_uri.html\"></head>\n<body></body></html>";
response.data_length = strlen(response.data);
response.content_length = 0;
HTTPSRV_cgi_write(&response);

Edit:

Regarding the content length: If it is set to zero, HTTP server will signalize end of response entity by closing the connection and thus ignoring keep-alive flag of session.

Edit2:

In MQX 4.2 there will be support for chunked transmission encoding so you will not have to worry about content length.

Best regards,

Karel

Re: MQX 4.1 HTTPSRV: How to modify the reponse header?

pbanta — Mon, 13 Oct 2014 15:22:36 GMT

Hi Karel,

Thanks for the reply. I'll give the http-equip attribute a try. Looks like a good alternative as long as it works with IE, Firefox, Chrome, Safari.

Best regards,

Paul