NetTalk WebClient
Available in NetTalk Desktop, NetTalk Server and NetTalk Apps. Applies to Desktop (ABC or Clarion) apps.
Introduction
The WebClient Class is used to let your program interact with web servers.
Those servers might be serving up files, they might be a Web Service API, or
you might be sending information, or files to those servers.
The
WebClient class allows your program to act as an HTTP (or HTTPS) client. The
defaults for HTTPS are usually correct, and it is not usually necessary to
set any extra properties for HTTPS. If the URL you are connecting to
contains HTTPS as the protocol then the object will automatically operate in
secure mode. If you are using HTTPS you will need to distribute some extra
DLL and PEM files.
Since SOAP and REST typically exist on top of HTTP this class is also
the one you will use if you need to communicate with a SOAP or REST server.
WebClient objects use asynchronous communications, meaning that your
window will "stay alive" as the communications happens in the background.
This means that the WebClient object must be on a procedure with a window,
not a source procedure. (You can however hide the window if you like).
The most common request methods are Get and
Post. Note that when you make a request the code
carries on before the result arrives. When the result has arrived from the
server then the PageReceived method is called
(and the ThisPage property contains the returned
header and data.) If a network error occurs then the
ErrorTrap method will be called instead. If the remote server does
not like your request (for whatever reason) and returns an error then that
error will flow into PageReceived , not
ErrorTrap.
See Also
Many other classes are related to, or depend on, the WebClient class.
JumpStart
- Add the NetTalk Global Extension to your application
- On a Window, add a NetTalk Object Extension.
- Choose a name for the object (this document will use the name
net) and set the base class to
NetWebClient
Terminology
| Name | Description |
|---|
| HTTP | HyperText Transfer Protocol - this is the
"language" of web servers - it is the building block of all
communications between a WebServer and a WebClient. (Your browser is
an example of a WebClient) |
| HTTPS | The same as HTTP, but over a secure connection.
Connections are secured using TLS. |
| TLS | Transport Layer Security. This used to be known as
SSL (Secure Sockets Layer.) |
| Host | The URL or IP address of the Web server you want to
talk to. |
| Port | The port number you are connecting to. The usual
value is 80 for HTTP sites and 443 for Secure (TLS) sites. |
| GET, POST, PUT, DELETE | These are the typical commands
you will use to interact with a web server. Also known as "HTTP
VERBS" these are the basic commands of the HTTP protocol. |
Upgrading
If you are upgrading from an earlier version of NetTalk to NetTalk 10 or
later and you are getting
errors then read this section for required, or suggested, changes.
- In NetTalk 10 the Page property (which
was a STRING) is now renamed as
ThisPage, and is declared as a
STRINGTHEORY object.
This will affect
code you may have embedded in the PageReceived
method.
The contents
of the ThisPage property can be retrieved
using ThisPage.GetValue(). For example
whatever(self.page)
would be replaced
with
whatever(self.thispage.GetValue())
In some cases (notably when calling xFiles.Load)
the self.page parameter was being passed as a pointer. In these cases
the code is replaced with
whatever(self.thispage.GetValuePtr())
- The PageLen property has been removed.
Use self.ThisPage.Length() instead.
- The _Command property (String) has been
replaced with _CommandText (StringTheory.)
Use _CommandText.GetValue()
- The _PageContentLen property has been
renamed to PageContentLen.
- The _GetContentType method has been
renamed to GetContentType.
- The _HTTPVersion property has been
renamed to HTTPVersion. As from version 9.20
this property defaults to 1.1 not 1.0.
If you have this line in your
embed code;
net._HTTPVersion = 'HTTP/1.1'
then you can just remove the line.
DLL Distribution
Get a Web Page
The simplest command to a web server is a simple GET. (The FETCH method
works exactly the same as the GET - the two are synonyms of each other - you
can use that method instead if you prefer.)
The basic syntax of the
GET method is a single parameter which is the URL of the page (or file) to
fetch from the server. For example;
net.Get('www.capesoft.com')
If the site is using HTTPS then simply add that to the front of the URL
net.Get('https://www.capesoft.com')
Parameters can be added to a URL in the usual URL encoded way;
net.Get('www.capesoft.com?products=all&amazing=yes')
The command will begin executing in the background. When the response
has arrived then the PageRecieved
method will be called. The contents of the response will be in the
ThisPage property. The response will include the header and the
response text. To remove the header part use the
RemoveHeader method.
You can save the response to a file, with
or without the header. To save it with the header;
net.ThisPage.SaveFile('filename')
To save
it without the header
net.SavePage('filename')
Post Data to a Web Server
When sending data to a server the most common method that you are required
to use is Post. Post is similar to Get in that you use a simple URL as the
parameter, but a Post can also send Data to the server as part of the
request.
For example
net.Post('www.capesoft.com',data)
The data parameter can be either a string, or a StringTheory object.
The format of data depends on what the server is expecting - it might be
json, or xml, or indeed anything. That said, the default format is
form-encoding. If the post you are doing takes form encoded data, then use
the SetValue method to add fields to the request. For example;
net.SetValue('CustomerName','Charlie')
net.SetValue('Company','Capesoft')Using this method you can
attach files to the upload as well
net.SetValue('somefile','c:\temp\a.pdf',true)
When doing a post in this way, just leave the second parameter to the
Post method with blank, or omitted.
net.Post(url)
XML
When
sending a Post to a WebService the data may need to be in XML format.
Use your favorite XML creation tool to format this text.
You
will need to set the Content-Type header to be XML so that the server
knows the data is in XML format.
data =
'<some xml>'
net.SetContentType('xml')
net.post(url,data)
JSON
When
sending a Post to a WebService the data may need to be in JSON format.
Use your favorite JSON creation tool to format this text.
You
will need to set the Content-Type header to be JSON so that the server
knows the data is in JSON format.
data =
'{some json}'
net.SetContentType('json')
net.post(url,data)
Attaching a File to an Upload
There are three common ways of uploading a file to a web server.
- Inside the XML data. (Typically to a WebService API)
- Inside the JSON data. (Typically to a WebService API)
- As part of a Multipart/form-data post. (Typically mimicking a
POST from a browser's File Upload button.)
If the file is included in XML then it is typically Base64 encoded,
and included in the XML as a simple text field. Consult your XML tool
documentation if this is the approach the server requires.
If the file is included in JSON then it is typically JSONEncoded and
included in the JSON as a simple text field. Consult your JSON tool
documentation if this is the approach your server requires.
If you are mimicking a Post from a browser, and uploading the file as
a multipart form-data encoded Post, then use the SetValue method to add
one or more fields (including the file) to the data prior to calling the
Post method.
Reply Format
Some requests will require that you tell the server what format the reply
should be in. This is done using the SetAccept method.
net.SetAccept('xml')
Authentication
Some web servers make use of BASIC or DIGEST authentication. This is
authentication which typically requires 2 parts; the username and the
password, and the authentication is automatically added into the header for
you.
You can easily add authentication to your request by adding the
following line before your call to GET or POST.
For Basic
Authentication you would add
net.Authorization
= net.CreateAuthorizationString(User,Password,Net:WebBasicAuthentication,true)
And for Digest Authentication you would add
net.Authorization =
net.CreateAuthorizationString(User,Password,Net:WebDigestAuthentication,true)
Cookies
Cookies are variables sent to you by a web server. When making subsequent
requests to the same server then (usually) the cookies should be sent with
the reply.
NetTalk includes the ability to parse cookies from
incoming replies, and include them (when talking to the same host) with
subsequent requests by the same object. To turn this ability on set
net.OptionAutoCookie = true
before the first
call to the server.
In additional you can add other cookies to the
request using the SetCookie method.
net.SetCookie('whatever','somevalue')
Progress Bar Control
When doing a large upload, or download, it's useful for the user to see a progress bar so they get some idea of how far it still has to go.
The NetWebClient class has support for progress controls built in.
To
use the progress control simply set the ProgressControl property of the
object to the Field Equate of the progress control on your window. For
example;
net.ProgressControl = ?progress1
The control will be updated automatically. It is updated as incoming
packets are received for downloads and at 1.5 second intervals for uploads.
Note that when doing a PUT or POST request from a web client to a web
server there are two distinct events which are monitored by the progress
bat. The first is the upload of the Post data. The second is the download of
the reply. So with a PUT or POST command the user may see the progress
control run "twice". Of course one (or both) of the two operations may be
very fast.
SOAP
SOAP is a particular form of XML. So a SOAP server is a web server which
expects incoming data to be formatted as XML (and specifically SOAP XML).
SOAP servers typically only support the GET or POST methods.
The
data returned is in XML format.
Formatting requests for SOAP 1.1 and
SOAP 1.2 is slightly different.
SOAP 1.1
In SOAP 1.1 an additional header is required in the actual WebClient
request. The SOAPAction property is used for this. The SOAPAction
header is set to the name of the server, and the name of the method
being called. For example;
net.SetContentType('soap11')
net.SetAccept('xml')
net.SOAPAction = clip(Server) & '/dbCustomers'
net.Post(url,data)
SOAP 1.2
SOAP 1.2 does not require the custom header to be set, but the content
type does need to be set.
net.SetContentType('soap12')
net.SetAccept('xml')
net.Post(url,data)
REST
REST is an alternative to SOAP. It serves the same purpose but is JSON based
rather than XML based. REST is also a lot less formal than SOAP - so there's
a lot more variety between servers, but equally it's a lot simpler to work
with so is preferred by many developers of both servers and clients.
One of the big differences between SOAP and REST is that REST often applies
meaning to the HTTP verb used - so in addition to GET and POST it is also
common to make use of the PUT and DELETE methods. PUT has the same
parameters as POST and DELETE typically has the same parameters as GET.
net.SetContentType('json')
net.SetAccept('json')
net.Post(url,data)
Advanced
REST is less structured than SOAP, so pretty much anything goes. In some
extreme cases the format of the request is different to what is typical
for a WebClient. For example a GET request might include data like a
POST and so on. For this reason all the NetTalk methods (GET, PUT, POST,
DELETE) support a second "data" parameter. This parameter can be either
a String or a StringTheory object.
TLS (SSL) Connections
Connecting over TLS using the HTTPS protocol is not much different from
connecting over non-secure connections using HTTP. The WebClient class sits
above the connection itself, therefore it has no special code to deal with
the connection.
The WebClient class does however inherit from the
NetSimple class and so the TLS related properties there are in use here as
well.
The following table contains some of the most useful properties,
however this list is not exhaustive - see the NetSimple documentation for a
complete list of properties.
| Property | Description |
|---|
| SSL | Set to true if the connection is over, or will
be over, TLS. You do not need to set this, it is set
automatically if the URL being requests begins with HTTPS. |
| SSLMethod | The SSL (TLS) version to use when
connecting to the server. The default value is
NET:SSLMethodTLS. For more options
on this method see the NetAll.Inc
file. |
SSLCertificateOptions.
ServerName | If set then this is an alternate test for the
server certificate name. Usually the name has to match the
hostname you are connecting to, but if you know the certificate
will have a wrong (but fixed) name then you can enter the
expected name here. |
SSLCertificateOptions.
DontVerifyRemoteCertificateCommonName | If set to true
then the common name of the server certificate is not matched to
the server the client is connecting to. This setting should be
used with caution - it allows for a man-in-the-middle attack. |
SSLCertificateOptions.
DontVerifyRemoteCertificateWithCARoot | If set to true
then the server certificate is not tested against the
caroot.pem file to see if it is
trusted. Use this setting with caution, if set then the
communication with the server will be encrypted, but the server
itself is not trusted. This setting also allows for a
man-in-the-middle attack to take place. |
| CertificateFile | The location of a client-side
certificate file. This is very rarely used with web servers. |
| PrivateKeyFile | The location of a client-side private
key file. This is very rarely used with web servers. |
Class Reference
NetWebClient
Derivation
- NetWebClient ( NetWww.Inc / NetWww.Clw )
Properties
| Property | Description |
|---|
| AcceptEncoding | Defaults to gzip - Tells the server
that the response may be compressed using the gzip algorithm.
Responses that arrive gzipped are automatically unzipped before
being passed to the PageReceived
method. |
| AsyncOpenTimeout | The amount of time, in hundreds of
a second, to wait before an attempt to Open a request fails. The
default value for this setting is 900, or 9 seconds. |
| Busy | If this property is set then a response is
being received from the web server. |
| BytesWritten | the number of bytes written to the disk
by the SavePage method. |
| CacheControl | Allows you to set the Cache-Control
header of a request (before making the request). |
| CanUseProxy | Set to true if this object can access
the URL via a Proxy server. |
| CustomHeader | Allows you to add a custom header to
the request. For example;
net.customheader = 'xxx-whatever: good-to-go' |
| HeaderLen | The length of the header part of the
received page. |
| HeaderOnly | If this is set to true then the next
request made to the server will only fetch the Header part of
the response from the server. This allows you to determine the
capabilities of the server, as well as (possibly) the
prospective size of the response to the request, before asking
for the actual response. |
| HTTPVersion | As from build 9.20 the default for this
is HTTP/1.1 - Previously it was
HTTP/1.0. |
| FormEncodeType | Set to
multipart/form-data if the form will be submitted as a
multipart form. |
| OptionAutoCookie | If set to true
then incoming cookies are automatically added to the
queue and sent out with subsequent requests. |
| OptionDontRedirect | If set to
false (the default) then a Redirect response (30x) from
the server will automatically be followed to the specified URL. |
| OptionDontSetCookieOnRedirect | If
true stops the SetCookie being put
into the Cookie on Redirection |
| OptionFinishOnEndHTMLTag | This option (if set to
true) will cause
PageReceived to be called if the
page we are receiving has no content-length, and the last 7
characters are </html> |
| PageContentLen | The size of the incoming response
from the server - if this header has been set by the server
before sending. |
| PageChunked | Is set to true if the response from the
server is in chunked format. |
| Progress | A property that contains the progress
percentage (from 1 to 100) of the incoming reply from a server. |
| ProgressControl | A property that contains the FEQ of
a Progress bar control on the window. If set then uploads and
downloads will automatically give progress feedback to the user
as the upload and download happens. For more information see
Progress Bar Control. |
RangeStart
Range End | Allows the client to set a
range of bytes (0 based, not 1 based) from the file being
fetched.
Not all servers support ranges. If a server returns
a header;
Accept-Ranges: none
then it definitely does not support ranges. If it returns a
header
Accept-Ranges: bytes
then it definitely does support
ranges. If it returns neither of these then it may, or may not,
support ranges.
A NetTalk 10 server supports range
requests for static files, but not for dynamically generated
pages. |
| SOAPAction | Set this to the value of the
SOAPAction header as required by
SOAP 1.1 servers, before doing a request. See
SOAP. |
| ThisPage | A StringTheory object containing the
response from the remote server. This property is set when the
PageReceived method is called. |
Methods
| Method | Description |
|---|
| CreateAuthorizationString | See
NetWebHttp CreateAuthorizationString |
| Delete | Sends a DELETE
request to a web server. |
| DeleteCookie | Deletes a
cookie from the cookie queue. |
| ErrorTrap | See NetSimple ErrorTrap. |
| Get | Sends a GET request to a web
server. |
| Fetch | See Get. |
| PageReceived | Is called
when a response is received from the server. |
| Patch | Sends a PATCH request to a web
server. |
| Post | Sends a POST request to a web
server. |
| Put | Sends a PUT request to a web
server. |
| RemoveHeader | Removes the
header part of a response from the server. |
| SavePage | Saves the data part
of the page, not the header, to a file on the disk. |
| SetAccept | Sets the Accept header for the outgoing
request |
| SetAllHeadersDefault | Sets all the headers values for
requests back to their default state. |
| SetContentType | Sets
the Content Type header for the outgoing request. |
| SetCookie | See NetWebHttp SetCookie |
| SetValue | Sets a Form Field
value in preparation for doing a Post or Put. |
| Start | Sets the object back to a
virgin state. |
Delete
Delete (String p_Url,[String p_PostString | StringTheory p_PostString])
Description
Makes a call to the server using the DELETE verb.
Parameters
| Parameter | Description |
|---|
| p_Url | The fully formed URL containing
the host, path, and resource of the parameters. URL
encoded parameters can also be used here. |
| p_PostString | An optional string (or
StringTheory object) which is sent to the server as
part of the request. This data is sent as "Post
Data" (ie after the HTTP header) even though a
DELETE
typically does not expect Post data. This parameter
is only rarely used when talking to a server that
requires Post data with a DELETE request. |
Return Value
The method returns nothing.
See Also
Post,
Put,
Get,
Patch
DeleteCookie
DeleteCookie (String p_Name)
Description
Deletes a cookie from the cookie queue.
Parameters
| Parameter | Description |
|---|
| p_Name | The name of the cookie to delete. |
Return Value
The method returns nothing.
See Also
SetCookie
Get / Fetch
Get (String p_Url,[String p_PostString | StringTheory p_PostString])
Fetch (String p_Url)
Description
Makes a call to the server using the GET
verb.
Either the GET or FETCH method name can be used, they do the
same thing.
Parameters
| Parameter | Description |
|---|
| p_Url | The fully formed URL containing
the host, path, and resource of the parameters. URL
encoded parameters can also be used here. |
| p_PostString | An optional string (or
StringTheory object) which is sent to the server as
part of the request. This data is sent as "Post
Data" (ie after the HTTP header) even though a GET
typically does not expect Post data. This parameter
is only rarely used when talking to a server that
requires Post data with a GET request. |
Return Value
The method returns nothing.
See Also
Post,
Put,
Delete,
Patch
PageReceived
PageReceived ()
Description
Is called when a response is received from the server. The whole
response (including the header and data) is in the ThisPage
property. A request is sent to the server using one of the
request methods,
Get,
Post,
Put,
Delete or
Patch.
This is one of the most important embed points in the class
because it determines what you do with the response from the
server.
ExamplesTo
remove the header at this point call the RemoveHeader method.
self.RemoveHeader()
something =
self.ThisPage.GetValue()To save the page (with
the header removed, even if you have not called RemoveHeader)
call the SavePage method.
self.SavePage(filename)To save the page, with the
header included
self.thispage.saveFile(filename)
Return Value
The method returns nothing.
See Also
Get,
Put,
Delete,
Post,
Patch,
RemoveHeader,
SavePage
Patch
Patch (String p_Url,[String p_PostString | StringTheory p_PostString])
Description
Makes a call to the server using the
PATCH verb.
Parameters
| Parameter | Description |
|---|
| p_Url | The fully formed URL containing
the host, path, and resource of the parameters. URL
encoded parameters can also be used here. |
| p_PostString | An optional string (or
StringTheory object) which is sent to the server as
part of the request. This data is sent as "Post
Data" - ie after the HTTP header. |
Return Value
The method returns nothing.
See Also
Get,
Put,
Delete,
Post
Post
Post (String p_Url,[String p_PostString | StringTheory p_PostString])
Description
Makes a call to the server using the
POST verb.
Parameters
| Parameter | Description |
|---|
| p_Url | The fully formed URL containing
the host, path, and resource of the parameters. URL
encoded parameters can also be used here. |
| p_PostString | An optional string (or
StringTheory object) which is sent to the server as
part of the request. This data is sent as "Post
Data" - ie after the HTTP header. |
Return Value
The method returns nothing.
See Also
Get,
Put,
Delete,
Patch
Put
Put (String p_Url,[String p_PostString | StringTheory p_PostString])
Description
Makes a call to the server using the
PUT verb.
Parameters
| Parameter | Description |
|---|
| p_Url | The fully formed URL containing
the host, path, and resource of the parameters. URL
encoded parameters can also be used here. |
| p_PostString | An optional string (or
StringTheory object) which is sent to the server as
part of the request. This data is sent as "Post
Data" - ie after the HTTP header. |
Return Value
The method returns nothing.
See Also
Get,
Post,
Delete,
Patch
RemoveHeader
RemoveHeader ()
Description
Removes the header part of the response from the
thispage property.
ExampleIn the
PageReceived method.
self.RemoveHeader()
something =
self.ThisPage.GetValue()
Return Value
The method returns nothing.
See Also
PageReceived
SavePage
SavePage (string p_FileName)
Description
Saves the data part, not the header, to a file on the disk.
Parameters
| Parameter | Description |
|---|
| p_FileName | The name, and path, of the
file to save. If the file exists it will be
overwritten. |
ExampleIn the
PageReceived method.
self.SavePage('c:\temp\a.png')
Return Value
The method returns nothing. The
BytesWritten property is updated to indicate the number
of bytes written to the disk.
See Also
PageReceived
SetAccept
SetAccept(String pType)
Description
Sets the Accept_ property (and hence the Accept
header) for the outgoing request.
The Accept header
tells the server what format to use for the reply. In most cases
this header is ignored, unless the server has a choice of what
to return. For example a Web Service API may allow you to choose
between an XML or JSON response.
Parameters
| Parameter | Description |
|---|
| pType | The name of a file, or extension,
which indicates the type of data being requested.
Most often is one of 'xml',
or 'json' or left as the
default value. |
Example
To set it to be XML
net.SetAccept('xml')
To
set it to be JSON
net.SetAccept('json')
Return Value
The method returns nothing.
See Also
SetContentType
SetAllHeadersDefault
SetAllHeadersDefault()
Description
Sets all the headers for a request back to their default state.
Example
net.SetAllHeadersDefault()
Return Value
The method returns nothing.
See Also
Start
SetContentType
SetContentType (String pType)
Description
Sets the ContentType property (and hence the Content-Type
header) for the outgoing request.
The Content-Type header
tells the server what format is being used for the data attached
to the request. This applies to Post data, typically sent with
the
Post or
Put
method.
If this method is not called then the
content-type will default to blank, which is then either set to
application/x-www-form-urlencoded or
multipart/form-data if the data
includes a disk file.
Parameters
| Parameter | Description |
|---|
| pType | The name of a file, or extension,
which indicates the type of data being used in the
request. Most often is one of
'xml', or 'json'
or left as the default value. |
ExampleTo force it
to be
application/x-www-form-urlencoded
net.SetContentType('form')To
force it to be
multipart/form-data
net.SetContentType('multipart')
To set it to be XML
net.SetContentType('xml')
To
set it to be JSON
net.SetContentType('json')
Return Value
The method returns nothing.
See Also
SetValue,
Post,
Put,
SetAccept
SetValue
SetValue (String pName, String pValue,
Long pFile=0, <String pContentType>, <String pCustomHeader>)
Description
When a Post or Put method is sent to a server then additional
data is also usually sent to the server.
If the Post
data format is multipart/form-data or application/x-www-form-urlencoded
then the values (including files) can be added to the post using
this method.
Parameters
| Parameter | Description |
|---|
| pName | The name of the field. |
| pValue | The value of the field. If the
value is a file attachment on the disk then set this
to be the path, and filename, of the file on the
disk. |
| pFile | If the value field contains a
filename then set this to true. |
| pContentType | If the field has a custom
Content-Type then set it here. If omitted then the
content type is set based on the extension of the
filename. |
| pCustomHeader | If a custom header has to
be included with the field then set it here. |
Example
net.SetValue('name','nettalk')
net.setvalue('invoice','c:\temp\invoices.pdf',true) !
content-type is application/pdf
net.setvalue('logo','c:\temp\logo',true,'bmp')
Return Value
The method returns nothing.
See Also
Post Data to a Web Server
Start
Start()
Description
Sets all the object back to a virgin state.
Example
net.start()
Return Value
The method returns nothing.
See Also
SetAllHeadersDefault
ClassNetWebHttp
Derivation
- NetWebHttp ( NetHttp.Inc / NetHttp.Clw
)
Properties
| Property | Description |
|---|
| Authorization | Contains the header used to
authenticate with the server, based on the user name and
password. |
| ProxyAuthorization | Contains the header used to
authenticate with the proxy server, based on the user name and
password. |
| AuthUser | The UserName used in the most recent call
to CreateAuthorizationString |
| authPassword | The Password used in the most recent
call to CreateAuthorizationString |
Methods
| Method | Description |
|---|
| CreateAuthorizationString |
Generates an authorization string based on a user name and
password. Supports Basic and Digest authentication. |
| CreateAuthorizationStringOAuth1 |
Generates an authorization string based on tokens for
communicating with an OAuth1 Web Service. |
CreateGMTDate
CreateUTCDate | Create a date
time stamp of the form Fri, 8 Oct 2004 16:54:48 GMT |
| DontSendCookie | Delete
a cookie from the cookie queue |
| GetContentType | Return
the appropriate content-type value based on a filename |
| SetCookie | Add, or change, a
cookie in the cookie queue. |
CreateAuthorizationString
CreateAuthorizationString (string p_UserName, string p_Password, long p_AuthorizationMethod, long p_Options=0)
Description
Generates an authorization string based on a user name and
password. Authorization strings are used in HTTP headers when
authenticating with the server as either BASIC or DIGEST
authentication.
If given a choice, then BASIC
authentication is recommended for servers connected to over
HTTPS - DIGEST authentication is recommended for servers
connected to over HTTP.
Parameters
| Parameter | Description |
|---|
| p_Username | The user name to include in
the authorisation string. |
| p_Password | The password to include in
the authorisation string. |
| p_AuthorizationMethod | One of
Net:WebBasicAuthentication
or Net:WebDigestAuthentication |
| p_Options | st:NoWrap - do not wrap the
result. Recommended. (Basic Authentication Only)
net:proxy - authenticate against proxy server -
(Digest Only) |
Return Value
The method returns the Authentication string. It is then
most commonly assigned to the
Authorization
property.
When this method is called the AuthUser and
Password properties are automatically updated to these values.
Examplenet.Authorization
= net.CreateAuthorizationString(User,Password,Net:WebBasicAuthentication,true)
See Also
Authentication
CreateAuthorizationStringOAuth1
CreateAuthorizationStringOAuth1
(String pVerb, String pUrl, AuthParametersGroup pParms)
Description
Used by the OAuth class to generate the Authorization header
string for OAuth 1 requests.
Parameters
| Parameter | Description |
|---|
| pVerb | The HTTP verb being used. For
example, GET, POST, PUT, DELETE |
| pUrl | The URL being connected to |
| pParms | a AuthParametersGroup. (Same as a
oAuthParametersGroup). Typically passed to, and
back from the NetOAuth
class. |
Return Value
The method returns the Authentication string. It is then
most commonly assigned to the
Authorization
property.
Example
s group(AuthParametersGroup).
code
s = whatever
self.Authorization =
self.CreateAuthorizationStringOAuth1('GET',pRequestTokenURL, s )
See Also
OAuth
CreateGMTDate / CreateUTCDate
CreateGMTDate (long p_Date=0, long
p_Time=0)
CreateUTCDate (long p_Date=0, long p_Time=0)
Description
Create a date time stamp of the form Fri, 8 Oct 2004 16:54:48
GMT.
Local time is automatically converted to UTC time when
generating the timestamp.
Parameters
| Parameter | Description |
|---|
| p_Date | The date of the time stamp. If
omitted, or 0, then defaults to today. |
| p_Time | The time of the time stamp. If
omitted, or 0, then defaults to today. |
Return Value
The method returns a string of the form Dayname, DayNumber
MonthName Year Time GMT
See Also
DontSendCookie
DontSendCookie (String p_Name)
Description
Deletes a cookie from the cookie queue.
This method is used by the WebServer only, for the WebClient see
DeleteCookie.
Parameters
| Parameter | Description |
|---|
| p_Name | The name of the cookie to delete. |
Return Value
The method returns nothing.
See Also
SetCookie
GetContentType
GetContentType (string p_FileName)
Description
Return the appropriate content-type header value based on a
filename.
Parameters
| Parameter | Description |
|---|
| p_FileName | The name of the file (or
extension) to return the content-type for. |
Return Value
The method returns a content-type string suitable for
being applied to the content header.
Example
s = net.GetContentType('json')
s = net.GetContentType('c:\temp\whatever.jpg')
See Also
Post Data to a Web Server
SetCookie
SetCookie (String p_name, String
p_Value, <Long p_Date>, <Long p_Time>, <Long p_Secure>, <String
p_Path>, <String p_Domain>, Long p_HttpOnly=0)
Description
Adds a cookie to the cookie queue. The cookies in the cookie
queue are automatically included on the next (and subsequent)
calls to the server.
Parameters
| Parameter | Description |
|---|
| p_Name | The name of the cookie to add. |
| p_Value | The value of the cookie to add. |
| p_Date | (server only) The date on which
the cookie expires. |
| p_Time | (server only) The time on which
the cookie expires. |
| p_Secure | (server only) If set then the
cookie will only be used on secure (HTTPS)
connections. |
| p_Path | (server only) The Path attribute
for the cookie. |
| p_Domain | (server only) The Domain
attribute of the cookie |
| p_HttpOnly | (server only) If set then the
cookie is only available to the browser, and not to
JavaScript running in the browser. |
Return Value
The method returns nothing.
See Also
For more information on cookie attributes see
Wikipedia.
Cookies
NetWebRoot
Derivation
- NetWebRoot ( NetHttp.Inc / NetHttp.Clw
)
Methods
| Method | Description |
|---|
| NormalizeURL | Changes \ in a URL to /, makes sure the parameter-separator is a
?, and all the other parameters are separated by a ? |
| GetHeaderField | Get a
header field value from a request or a response. |
NormalizeURL
NormalizeURL (String pURL)
Description
Changes \ in a URL to /, makes sure the parameter-separator is a
?, and all the other parameters are separated by a ?
Parameters
| Parameter | Description |
|---|
| p_Url | The fully formed URL containing
the host, path, and resource of the parameters. URL
encoded parameters can also be used here. |
Return Value
The method returns a string containing the normalized URL.
See Also
GetHeaderField
GetHeaderField (string p_SearchString,
StringTheory p_MainString | *string p_MainString, long
p_StartPos=1, long p_EndPos=0, long p_CaseInsensitive=true)
Description
Get a header field value from a request or a response.
Parameters
| Parameter | Description |
|---|
| p_SearchString | The header value to look
for. |
| p_MainString | The string, or StringTheory
object, containing the request, or response. |
| p_StartPos | The start position in the
string to commence the search. If omitted, or 0,
then the start of the string is used. |
| p_EndPos | The end position in the string
to search for the header. If omitted or 0 then the
end of the string is used. |
| p_CaseInsensitive | If
true (the default value)
then the header name is considered to be case
insensitive. |
Return Value
The method returns a string containing the value of the
header field. If the header is not found then a blank string is
returned.
Example
result = self.GetHeaderField
('content-length',self.thispage)
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