How to "Post" data to the web server ?

[marc.assin]

Hi,

I'm integrating a Cisco IP camera on the NAS.
So far, so good, I can see the stream.

The camera allows for motion detection, when such an event happens, some actions can take place.
So far I've got email and ftp working.
I'm mainly interested in the "http notification" but I'm unable to make it work. I understand the cam uses a http_post method to send the event data to the web server, but there it stops.
Any help, please ?
Are there any pre-requisites ?
Any modifs to php.ini or apache.conf ?

Thank you

[TonyPh12345]

Not sure what you're asking.

Basically, if it's using a POST, then you need to have a CGI on the server side to catch the post and interpret the data that's POSTed.

[marc.assin]

Hi Tony,

Thank you for taking the time to reply.

Not sure what you're asking.

Sorry for beeing so fuzzy, I'm a beginner.

Basically, if it's using a POST, then you need to have a CGI on the server side to catch the post and interpret the data that's POSTed.

My first assumption was (as nothing worked) that something needed to be enabled at the NAS side. That's obviously wrong. I slowly realize what you are saying, that I need to do some programming to catch the data posted by the cam. I'm going to do it in PHP, but for a non-programmer it's not easy.

Thanks

[P3R]

If you got FTP working, the pictures (or movies) can be put where you want them (maybe in the web directory to be displayed on your web?) and with the email you get notifications of the events.

What more do you expect to achieve with web postings?

[marc.assin]

Hi P3R,

If you got FTP working, the pictures (or movies) can be put where you want them

Indeed, that part is OK

What more do you expect to achieve with web postings?

Well, I didn't tell the whole story.
The cameras are part of a larger domotics project. I'm mainly interested in the asynch aspect of a trigger.
Suppose the cam is hanging on the ceiling of the hall, with a predefined motion detection area focused on the front door... and the cam triggers a 03:00 ...
I want to capture that event (the video is already saved) with a PHP script and trigger a KNX alarm, just like a standard KNX fire alarm or presence detector.
The camera is setup for HTTP notification, with URL base set to /Cam/Cam1/cam1.php.
When the camera detecs a motion, the PHP script is executed, but I'm unable to get any data from the POST.
I'm a beginner in this field, a short piece of code, supposed to run on a QNAP would be much appreciated
Here is my code

Code: Select all

echo "Hello World";
$file=fopen("kk.txt","w");
fwrite($file,"IP camera1 notification".chr(13).chr(10));
foreach ($arr as $key => $value) { 
    $toFile = "Key: $key; Value: $value \n"; 
fwrite($file, "$toFile") or die('Could not write to file');
} 
fclose($file);

[TonyPh12345]

If it's using POST, your PHP probably needs to be reading the contents out of the $_POST special variable.

So try, instead (noting that I substituted only a variable name...)

Code: Select all

echo "Hello World";
$file=fopen("kk.txt","w");
fwrite($file,"IP camera1 notification".chr(13).chr(10));
foreach ($_POST as $key => $value) { 
    $toFile = "Key: $key; Value: $value \n"; 
    fwrite($file, "$toFile") or die('Could not write to file');
} 
fclose($file);

See what that gets you.

Oh, btw, you might want to use the open mode "a" instead of "w" since "w" will OVERWRITE your file, and "a" will APPEND to your file.

[marc.assin]

If it's using POST, your PHP probably needs to be reading the contents out of the $_POST special variable.

Yes, most probably, that's what I'm trying since days....

See what that gets you.

No luck, the file has just the top string, no post data

What would the code look like if it wasn't a POST but a GET ?

Thank you for your time

[TonyPh12345]

Same thing, but using the variable $_GET.

That's a good way to troubleshoot, because you make all the get queries you want using your own browser...

http://your.webserver.name/cam/cam1/cam ... le2=value2 ... etc

There's actually ANOTHER variable $_REQUEST that will work with BOTH GET and POST methods.

I Googled some stuff and also came across this interesting tidbit:

http://www.bradino.com/php/empty-post-array/

[marc.assin]

Same thing, but using the variable $_GET.

This code

Code: Select all

foreach ($_GET as $key => $value) { 
    $toFile = "Key: $key; Value: $value" .chr(13).chr(10);
    fwrite($file, "$toFile") or die('Could not write to file');
}  

works fine and gives this result

Code: Select all

Key: action; Value: update
Key: DeviceName; Value: Cam-NO
Key: IPAddress; Value: 10.0.1.242
Key: MacAddress; Value: 00:1D:E5:EA:81:81
Key: DateTime; Value: 05302011 21:23:12
Key: ActivePostCount; Value: 1
Key: EventType; Value: 2
Key: EventState; Value: 1
Key: EventDescription; Value: 
Key: RegionIndex1; Value: 1
Key: DetectionThreshold1; Value: 50

This is great, but its an enum. Is it possible to get the count of elements and extract just 1 from the list ?
Also, this works only when the flag "Post" from the camera is NOT set.

I tried the Post method with the flag set, and was unable to get anything, any idea ? maybe a crummy doc ?

http://your.webserver.name/cam/cam1/cam ... le2=value2 ... etc

Thanks for the tip

http://www.bradino.com/php/empty-post-array/

I tried this with the cam flag Post, set

Code: Select all

$data=file_get_contents('php://input'); 
fwrite($file, $data);

guess what ?

Code: Select all

<?xml version="1.0" encoding="UTF-8"?><DeviceInfo><version>0.0.1</version><EventNotificationAlert><deviceName>Cam-NO</deviceName><ipAddress>10.0.1.242</ipAddress><macAddress>00:1D:E5:EA:81:81</macAddress><dateTime>05302011 21:37:15</dateTime><activePostCount>1</activePostCount><eventType>2</eventType><eventState>1</eventState><eventDescription></eventDescription><DetectionRegionList><DetectionRegionEntry><regionIndex>1</regionIndex><detectionThreshold>50</detectionThreshold></DetectionRegionEntry></DetectionRegionList></EventNotificationAlert></DeviceInfo>

What I'm still missing is a way to extract individual parameters.

Thank you for your precious help with a PHP newbee

[TonyPh12345]

Yes, you can select any specific "variable" via the method

$myvariable = $_GET["action"];

which should set $myvariable to the value "update" given the info you posted before.

you can find out how many elements are in the array using the function "count", as in

echo count($_GET);

It appears that with POST, it's actually sending an XML file instead of a set of elements & values. You'll have to code for that. If it were me, I'd probably stay with GET.

[marc.assin]

Yes, you can select any specific "variable" via the method
$myvariable = $_GET["action"];

Fine

you can find out how many elements are in the array using the function "count", as in
echo count($_GET);

Great !

I guess I'm all set now to start doing something usefull

A big many thanks.
Greetings from Midi-Pyrénées

[marc.assin]

Yes, you can select any specific "variable" via the method
$myvariable = $_GET["action"];

Mmmm, it took the newbee some time to realize what you are saying, but got it (finally)

I'm still puzzled. Given that the response of $_GET is an array, as in
$arr= $_GET;
I wonder why I can't exploit this array in the classical way, with an index, as in
echo $arr[0]
Maybe this array is "special" ?

[marc.assin]

I'm still puzzled. Given that the response of $_GET is an array, as in
$arr= $_GET;
I wonder why I can't exploit this array in the classical way, with an index, as in
echo $arr[0]

It's an associative array !
The newbee should read the doc more carefully

[TonyPh12345]

Heheh... Yeah, that's the classic "Potato" vs "PoTAHto" thing... (an English Idiom, sorry.

Perl calls such things HASHES, which are indexed through Keys. ARRAYs are indexed numerically. They're two different beasts entirely.

Depending on how deep you want to get into PHP, I strongly recommend the book "Learning PHP 5" from O'Reilly Press.