OUT_MSG_DESCRIPTION

void OUT_MSG_DESCRIPTION(int code)

Description

Writes error code, category and description to output buffer.

By default, it uses JSON format:

{"code":4,"category":"err","message":"Page not found"}

If NPP_MSG_DESCRIPTION_PIPES is defined, it uses pipe-delimited format:

4|err|Page not found

Category may be used to use different colors for the messages. Categories are defined in npp.h:

#define MSG_CAT_OK       "OK"
#define MSG_CAT_ERROR    "err"
#define MSG_CAT_WARNING  "war"
#define MSG_CAT_MESSAGE  "msg"

Returns

None

Example

/* in npp_app_main */

int ret=OK;

if ( REQ("login") )
{
    render_login();
}
else if ( REQ("do_login") )    /* via AJAX */
{
    ret = npp_usr_login();
    OUT_MSG_DESCRIPTION(ret);
}

Client-side JavaScript

JSON version:

let x = new XMLHttpRequest();

// "do_login" request...
// ...
// when ready:

if ( x.responseText.length > 0 )
{
    let r = JSON.parse(x.responseText);

    if ( r.code != 0 )  // error -- show message
    {
        show_msg(r.message);
    }
    else    // ok -- redirect
    {
        window.location.href = "dashboard";
    }
}
else
{
    show_msg("No response");
}

Pipes version:

let x = new XMLHttpRequest();

// "do_login" request...
// ...
// when ready:

if ( x.responseText.length > 0 )
{
    let r = x.responseText.split("|");

    if ( r[0] != "0" )  // error -- show message
    {
        show_msg(r[2]);
    }
    else    // ok -- redirect
    {
        window.location.href = "dashboard";
    }
}
else
{
    show_msg("No response");
}