session
Associated Tags
| Tag | Description |
|---|---|
| [session] | [session] has a unique value once the session is started. This value can be moved from one page to another using POST or GET, or appended to a link or redirect. |
| [sessionstart] | Starts a session by recording the day, time of the day, IP, Unique browser ID and (optional) the life in seconds, like in [sessionstart life=60] |
| [sessionend] | Kills a [session] by deleting it from the reserved.db |
| [sessionalive] | T (true) or F (false) Checks the current time against the session time to determine if the session is still alive |
| [sessionip] | Shows the IP address stored in the session, WebDNA formatted [ipaddress] (with leading 0's) |
| [sessionipmatch] | T (true) or F (false) Checks if the session IP address is the same as the current IP address |
| [browseridmatch] | T (true) or F (false) Checks the browser "fingerprint" against the session's browser ID |
| [sessiondate] | Shows the date stored in the session |
| [sessiontime] | Shows the time stored in the session |
| [sessionlife] | Calculates how many seconds a session has till it expires, shows 0 if expired |
| [sessionutime] | Shows the session's Unix Time (also known as POSIX time or Epoch time, defined as the number of seconds that have elapsed since 00:00:00 Universal Coordinated Time (UTC), Thursday, 1 January 1970) |
If a visitor's browser does not return a previously set session, then start a new session
sessionstart = [sessionstart life=1200] < starts a 20 min (60 seconds x 20 minutes) session
session = [session]
Now send the [session] value back to the visitor in a POST form:
<input type="hidden" name="session" value="[session]">
or in a url:
mypage.dna?session=[session]
When the visitor clicks through to mypage.dna, check for the session:
session = [session]
sessionalive = [sessionalive]
sessionlife = [sessionlife]
sessionIPmatch = [sessionIPmatch]
browserIDmatch = [browserIDmatch]
sessionip = [sessionip]
sessiondate = [sessiondate]
sessiontime = [sessiontime]
sessionutime = [sessionutime]
[sessionlife] will indicate how much longer the session has until it expires,
this is useful if a user is limited to the amount of time spent on a page or a website,
or if the need to record how long that user has spent on the site.
A simple use:
[if ("[sessionalive]"="T")]
[then] OK [/then]
[else] redirect out of secure area [/else]
[/if]HINT:
The page that RECEIVES the session MUST include the [session] tag, if it is being passed as a variable named "session" WebDNA will recognise the variable and use the value, however if the session value is being passed with a different name such as "CheckUser" then that variable needs to be converted to "session" on the receiving page, simply turn it into a text variable as such:
[text]session=[CheckUser][/text], now WebDNA can use the value to do further calculations on the session such as the ones above in the example.
ADVANTAGES:
Works with search engines
Security is increased by not allowing a cookie to be manipulated
Easier to use and much faster than a client-side cookie
Good for visitors who do not want to leave information behind them (cookie disabled)
Allows to easily kill a session
Allows to move a session from one browser to another browser
In certain rare cases, it is possible to find two identical browser "fingerprints" or BrowserID. It is not advised to do visitor recognition based only on Browser ID