Checking to see if HTTP_Get actually finds a file on the internet.

[preston2]

Ok, I am working on a method to have my app check a file on one of my domains on the internet. Then read the file and check the contents against some information in the registry.

So, look at the file on the internet, see if the registration number in the registry matches one listed as deactivated and if so notify the user and deactivate the app so they cannot make any changes.

I have all of that working fine but I also need to keep the app locked down if it has a deactivated registration number and they try to run it when they do not have an internet connection.

I can do that if I also have it set a field value that depending on its value would indicate that the app has been deactivated or not.

I also need to be able to reactivate the app by removing their registration number from the deactivated list in the file on the internet.

So, if it can find the file on the internet, test against it. If it cannot find the file then use the field value to determine if the app is deactivated or not.

I have tried " if .not. eval_valid("bad.body") " and that does not work.

I have tried reading " bad.error_code " and I get a value of 0 if it can find the file or if it cannot find the file so there is no difference between the two.

bad = http_get("http://www.shopcalsoftware.com/t5/notactive.txt")
if .not. eval_valid("bad.body")then 'This does not work
    ui_msg_box("Error","The Verification file was not downloaded from the server.",UI_STOP_SYMBOL)
else
    dim num_regs as N
    num_regs = count_textblocks(bad.body,"<badnum>","</badnum>")
    dim item[num_regs] as P
    dim i as N
    dim this_item as C
    dim numstring as c
    dim fixed_L as C
    dim fixed_R as C
    dim bad_num as C

    for i = 1 to num_regs
        this_item = extract_string(bad.body,"<badnum>","</badnum>",i,.t.)
        item[i].badnum = extract_string(this_item,"<badnum>","</badnum>")
        'numstring = property_to_string(item)
        numstring = this_item
        fixed_L = ltrim(numstring,"<[1]<badnum>")
        fixed_R = Rtrim(fixed_L,"</badnum>")
        bad_num = fixed_r
        if bad_num = vc_reg_num then
        vl_deactivated = .T.	
        	'Displays a message box (style:'OK Button', image: 'Information symbol', id: 'delined_reg').
DIM SHARED  declinedreg_result as N
DIM SHARED  declinedreg_OK_Button as L 
declinedreg_OK_Button = .F.

title_var = "Deactivated Registration Number"
message_text_var = <<%text%
Your registration number has been deactivated for one or more of the following reasons.

Your payment was declined or reversed.
You requested a new number which deactivated this one.

Please contact [email protected] if you feel this is in error.

Registration Number: %text%+vc_reg_num
declinedreg_result=ui_msg_box(title_var,message_text_var,UI_OK+ UI_FIRST_BUTTON_DEFAULT+ UI_INFORMATION_SYMBOL)
'Test to see which button on the message box was pressed....
SELECT
	CASE declinedreg_result = UI_OK_SELECTED
		declinedreg_OK_Button= .t.
END SELECT
sys_open("http://www.shopcalsoftware.com/helpdesk/")
        end if
next i
'a5_show_variable(property_to_string(item)) 'Uncomment for testing
if bad_num = "" then 'This does work if the file is not found but would also work if the file was empty.
	ui_msg_box("Error","The Verification file was not downloaded from the server.",UI_STOP_SYMBOL)
 end if

end if

[Tom Henkel]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

I just ran this from the interactive window and got the following:

dim bad as P
bad = http_get("http://www.shopcalsoftware.com/t5/notactive.txt")
?bad
= body = <item>
<cust>Jipster</cust>
<badnum>0563-6382-2534-5784-2048</badnum>
</item>
<item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<item>
<cust>My Laptop number for testing the trap</cust>
<badnum>8765-0443-5500-4389-1038</badnum>
</item>
<item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<item>
<cust>Tinhorn</cust>
<badnum>8287-0725-8520-7389-7108</badnum>
</item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item><cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<cust>Punk</cust>
<badnum>8384-0790-7574-2680-7078</badnum>
</item>
<item>
<cust>My Dev Machine</cust>
<badnum>4887-5748-5796-1476-5159</badnum>
</item>
error_code = 0
error_text = ""
headers = HTTP/1.1 200 OK
Date: Fri, 10 Jul 2015 16:01:17 GMT
Server: Apache
Last-Modified: Fri, 10 Jul 2015 15:54:28 GMT
Accept-Ranges: bytes
Content-Length: 973
Vary: Accept-Encoding
Connection: close
Content-Type: text/plain
+parsed_headers.

I then did this and got a "positive" result

?eval_valid("bad.body")
= .T.

I haven't done any web access from the desktop, but does this look like the results you wanted?

Try breaking you code down into pieces and testing with the interactive window and see where it is failing.

Tom

[preston2]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

Yes that eval_valid should work. In the interactive windows I get a .T. if the file is there and a .F. if it is not but in the actual code it does not see the true or false result on the " if .not. eval_valid("bad.body")then " statement. Maybe I need to change that to " if eval_valid("bad.body") = .F. then "

I am working on another way to tackle this.

If the file is there and it finds a matching registration number, set the value of a table field to True.

The autoexec script would then read the value of that field on startup and set the value of the vl_deactivated variable that will be used to lock the app down.

But if the script reads the matching number with an "-A" appended on the end of it then it will set the table field value to False.

The autoexec script would then read the value of that field on startup and set the value of the vl_deactivated variable to False which would then unlock the app and allow them to use it.

So do the test, write to a table if needed, read the table field to set the value of the vl_deactivated variable. If the " if eval_valid("bad.body") = .F. then " works then I can have it skip all the testing and just go straight to getting the value from the table.

This way once the app is locked down when they are connected to the net then it will stay locked down, internet connection or not, until they connect to the net again and I have set their registration number to be reactivated.

I have had a few buy my app, register it and then a few weeks later tell their CC company that they did not make the purchase an I get a charge back. I am fixing to put a stop to that. Once I get this working I will issue an update which all my customers will automatically get notified of when they start up their pc or when they start the app. Once they install the update the deactivation code will be in their app. I will then wait about a month and then add their registration numbers to the deactivate list. By waiting they will not associate the shut down with the update.

At least that is my thinking right now.

[preston2]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

Well none of the eval_valid stuff would work in the actual code.

But this worked

 if extract_string(bad.body,"<badnum>","</badnum>",1,.t.) = "" then

[Tom Henkel]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

What if you split the eval out of the if?

Dim ans1 as L
ans1 =  eval_valid("bad.body")then 'This does not work
if ans1 
  code here
  else
   error code here
end if

[preston2]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

What if you split the eval out of the if?

Dim ans1 as L
ans1 =  eval_valid("bad.body")then 'This does not work
if ans1 
  code here
  else
   error code here
end if

I will test that later. It may work.

Here is what I have working now.

dim bad as P
bad = http_get("http://www.shopcalsoftware.com/t5/notactive.txt")
if extract_string(bad.body,"<badnum>","</badnum>",1,.t.) = "" then
    goto SKIP
else
    dim num_regs as N
    num_regs = count_textblocks(bad.body,"<badnum>","</badnum>")
    dim item[num_regs] as P
    dim i as N
    dim this_item as C
    dim numstring as C
    for i = 1 to num_regs
        this_item = extract_string(bad.body,"<badnum>","</badnum>",i,.f.)
        item[i].badnum = extract_string(this_item,"<badnum>","</badnum>")
        numstring = this_item
        bad_num = numstring
        'Check to see if the registration number has been reactivated
        if numstring = vc_reg_num +"-A" then
    tpi = table.open("settings")
    tpi.index_primary_put("")
    tpi.fetch_first()
    WHILE .not. tpi.fetch_eof()
        tpi.change_begin()
        tpi.Deact = 1
        tpi.change_end()
        tpi.fetch_next()
    END WHILE
    tpi.close()
        end if
        'Check to see if the registration number has been deactivated
        if numstring = vc_reg_num then
    tpi = table.open("settings")
    tpi.index_primary_put("")
    tpi.fetch_first()
    WHILE .not. tpi.fetch_eof()
        tpi.change_begin()
        tpi.Deact = 2
        tpi.change_end()
        tpi.fetch_next()
    END WHILE
    tpi.close()       	
        end if
next i
end if
SKIP:

I also found by changing the .t. to .f. in the " this_item = extract_string(bad.body,"<badnum>","</badnum>",i,.f.) " statement I could do away will all the trim functions. This now just puts whatever is between the <badnum> </badnum> tags into the variable this_item.

[G Gabriel]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

eval_valid() is meant to evaluate if an expression is valid. The URL is not an expression, thus the result of this function as such will always be false.
Instead, if the file does not exist, the body will be empty, so instead, try:

bad = http_get("http://www.shopcalsoftware.com/t5/notactive.txt")
if bad.body=""
msgbox("File does not exist")
else
..........
end if

Hopefully, this URL is a point and click or hard-coded because if the user enters the wrong URL you will get a false false result.

[preston2]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

eval_valid() is meant to evaluate if an expression is valid. The URL is not an expression, thus the result of this function as such will always be false.
Instead, if the file does not exist, the body will be empty, so instead, try:

bad = http_get("http://www.shopcalsoftware.com/t5/notactive.txt")
if bad.body=""
msgbox("File does not exist")
else
..........
end if

Hopefully, this URL is a point and click or hard-coded because if the user enters the wrong URL you will get a false false result.

Thanks Gabe,

That is similar to what I came up with to get it to work.

The url is hard coded. The user has no say in the url.

The registration numbers I give my customers are computer specific. If they change them or try and remove them from the registry the app will shut down. The problem was that once I gave out a registration number they could use the app forever even if they had their CC company reverse the charges. Basically I have had two buy the app, register it and then in a few weeks tell their CC company they did not make the purchase and thus I ended up with a charge back and they ended up with my app for free.

With the code I was showing here and a few other sniblets of code in the autoexec I can now shut them down. Once the app is shut down it will still start up but tells them their license has been deactivated and all they can do inside the app is look at the first screen or contact me via my support system. Only I can reactivate the app and I will not do that until I get paid.

Anyway, the code I ended up with may not be the cleanest in the world but it works extremely well.

If anyone needs to do something similar I would be more than happy to share what I have.

[Raymond Lyons]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

eval_valid() is meant to evaluate if an expression is valid. The URL is not an expression, thus the result of this function as such will always be false.
Instead, if the file does not exist, the body will be empty, so instead, try:

bad = http_get("http://www.shopcalsoftware.com/t5/notactive.txt")
if bad.body=""
msgbox("File does not exist")
else
..........
end if

Hopefully, this URL is a point and click or hard-coded because if the user enters the wrong URL you will get a false false result.

I am far from an expert but Preston may want to check out HTTP_FETCH() and the status codes it can return.

Ray Lyons

[G Gabriel]

Re: Checking to see if HTTP_Get actually finds a file on the internet.

Preston may want to check out HTTP_FETCH() and the status codes it can return.
Ray Lyons

This should also work, a little more..but it should work with the same idea.