//
get action param
Char
*Action = "">
If(strcmp(Action,
“do_something_1”) == 0)
{
}
elses
If(strcmp(Action, “do_something_2”) == 0)
{
}
else
{
// print a debug error : action unknown
}
Hope
that helped,
Noam.
From:
lwip-users
[mailto:address@hidden]
On Behalf Of Giuseppe Modugno
Sent: Monday, November 13, 2017 6:09 PM
To: address@hidden
Subject: Re: [lwip-users] httpd: how to implement
AJAX
Il
13/11/2017 14:34, Noam Weissman ha scritto:
Hi,
I am using the following technic for AJAX.
Create an empty file named ajax.shtml or ajax.html and add it to your file list.
Inside the file you only write one tag without anything else. For example <!--#AjaxCall-->
Do not add CR or LF just the tag !!.
Now when you issue an AJAX call the WEB server opens the file, reads it and send its data.
Because the file has only the tag it will parse it, call your handler for that tag and send back
To the browser just your data !!
Ok, so
you use SSI to create dynamic data. I tried with custom
files, because *all the content* is dynamic (and not only
some parts, defined by specific tags).
If you use Juery it will look something like this... actually a function used as an event handler in
my own code:
function resetIO()
{
//Remove the dialog
returnToPage();
$.ajax({
url: "ajax.shtml",
dataType : "text",
type : "GET",
cache : false,
data : ({
ssid: ssid,
a: 'opReset',
type: 2
}),
error : function()
{
showMessage("Network Error: Sorry, there was a problem connecting to the server.");
},
success : function(result)
{
window.location.href = "">
}
});
}
In the above data you have the a: variable, this is your AJAX action !.
If I
understood well, data is translated in query string, in
your example:
GET
ajax.shtml?ssid=<ssid>&a=opReset&type=2
Of course, <ssid> is the value of ssid _javascript_
variable.
In your own SSI/CGI code you have a table with tags + callbacks... one of the callback function
Is your AJAX handler. Inside it you create an if <> else layout and handle the different actions.
The prototype for SSI callbacks
is:
typedef u16_t (*tSSIHandler)(
#if LWIP_HTTPD_SSI_RAW
const char* ssi_tag_name,
#else /* LWIP_HTTPD_SSI_RAW */
int iIndex,
#endif /* LWIP_HTTPD_SSI_RAW */
char *pcInsert, int
iInsertLen
#if LWIP_HTTPD_SSI_MULTIPART
, u16_t current_tag_part,
u16_t *next_tag_part
#endif /* LWIP_HTTPD_SSI_MULTIPART */
#if defined(LWIP_HTTPD_FILE_STATE) &&
LWIP_HTTPD_FILE_STATE
, void *connection_state
#endif /* LWIP_HTTPD_FILE_STATE */
);
I don't
see any reference to query string parameters. So how to
select the right action?
The HTTP server will read your ajax.shtml file and because it has nothing BUT your tag it will
only send back the dynamic data you process in your ajax handling function.
As said
before, it works if the dynamic content depends only from
the name of the file (ajax.shtml in your example) and not
from the action in the query string (a=opReset).
Where is my error?
Another question. I saw ssid in your _javascript_ example.
Is it related to a "session identifier"? If so, did you
implement a session mechanism over httpd?