 |
Claims  |
|
|
Having thus described the invention, what we desire to claim and secure by
Letters Patent is:
1. A computer system having a processor and a memory, and being connectable
to a remote network device by a network, the computer system comprising:
A) a downloader for downloading a copy of a remote document from the remote
network device into the memory of the computer system;
B) a local hypertext server;
C) a client a browser coupled with the local hypertext server for producing
browser request to modify the remote document;
D) an interceptor coupled with the client browser for intercepting
transmissions between the client browser and the remote network device,
the transmissions including a browser request to modify the remote
document;
E) a local application program executable by the processor of the computer
system for receiving information in a template from the client browser
through the local hypertext server, and, responsive to the intercepted
browser request, modifying the remote document copy to reflect the
information provided by the template; and
F) an update mechanism for causing the remote document on the remote
network device to be updated to reflect modifications made by the
application program to the remote document copy.
2. The computer system of claim 1, wherein the local hypertext server can
format the browser requests and direct the formatted requests to the local
application program.
3. The computer system of claim 1, wherein the local application program
utilizes CGI.
4. The computer system of claim 1, wherein the local application program
utilizes JAVA Applet.
5. The computer system of claim 1, wherein the local application program
utilizes ISAPI.
6. The computer system of claim 1, further including:
means for downloading an application program into the memory of the
computer system from the remote network device to produce the application
program, whereby the local application is compatible with the application
program on the remote network device.
7. The computer system of claim 6, wherein the downloading means includes:
A) means for receiving a transmission list from the remote network device
to the computer system;
B) means for downloading onto the local computer system, in response to
receipt of the list, the remote document from the remote network device to
produce the remote document copy;
C) means for creating a directory structure on the local computer system
that is substantially similar to a tree structure on the remote network
device, the tree structure on the remote network device including the
remote document; and
D) means for creating a mapping table including data for identifying the
location of the remote document copy in the local directory structure.
8. The computer system of claim 7:
A) further including means for using the local mapping table in locating
the remote document copy in the memory of the computer system; and
B) wherein, in response to the browser request to modify the remote
document, the local application program produces a modified remote
document copy.
9. The computer system of claim 8, further including:
means for displaying the modified remote document copy on a display device
included in the local computer system.
10. The computer system of claim 8, further including:
means for transmitting the modified remote document copy to the remote
network device for reconciliation with the remote document.
11. The computer system of claim 1, further including:
the downloader that is responsive to the browser request in downloading the
remote document copy; the application program making modifications in the
remote document copy in accordance with the browser request; and the
update mechanism causing the modifications in the remote document copy to
be reflected in the remote document on the remote network device.
12. The computer system of claim 1, further comprising a connection manager
for determining if the computer system is connected to the network, and
wherein, in response to the connection manager:
A) the downloader downloads the remote document copy when the computer
system is connected to the network;
B) the application program modifies the remote document copy when the
computer system is disconnect from the network; and
C) the update mechanism causes the remote document to be updated when the
computer system is connected to the network.
13. The computer system of claim 1, wherein the remote document is a
database.
14. A computer system having a processor and a memory, and being
connectable to a remote network device by a network, the computer system
comprising:
A) a browser;
B) an interceptor coupled with the browser for intercepting transmissions
between the browser and the remote network device when the computer system
is not connected to the network, the transmissions including a browser
request to modify a remote document that is stored on the remote network
device;
C) a downloader responsive to the browser request for downloading a local
copy of the remote document into the memory of the computer system from
the remote network device;
D) a hypertext server coupled with the interceptor for formatting data
received from the interceptor into formatted data having a selected
interface format, said formatted data including a number of changes to be
made in the remote document;
E) a local application program executable by the processor for receiving
the formatted data from the hypertext server and effectuating the changes
in the local copy of the remote document; and
F) a mechanism for accessing a reconciliation engine in the remote network
device to cause the changes in the local copy to be reflected in the
remote document on the remote network device.
15. The computer system of claim 14, wherein the local hypertext server
comprises:
A) an engine for formatting data received from the interceptor into the
formatted data;
B) a directory mapping table for identifying a location of the local copy
of the remote document in a directory structure that is substantially
similar to a tree structure on the remote network device, the tree
structure containing the remote document;
C) a data pump for downloading the remote document from the remote network
device; and
D) a cache control for causing the data pump to download the local copy of
the remote document from the remote network device to the memory of the
computer system.
16. The computer system of claim 14, wherein the interceptor comprises:
A) a redirector for receiving browser requests from the browser and
directing specified requests to the local hypertext server; and
B) a connection manager for determining if the computer system is connected
to the network.
17. A method of processing a remote document stored in a network device
remote from a local computer system, the local computer system having a
processor, a memory, and a client browser, and being connectable to the
remote network device by a network, the method comprising the steps of:
A) a client browser producing a browser request to modify the remote
document;
B) intercepting the browser request;
C) responsive to the browser request, downloading a copy of the remote
document from the remote network device into the memory of the computer
system;
D) a local hypertext server conveying information in a template from the
client browser to a local application program executable by the processor
of the local computer system;
E) using the local application program in modifying the remote document
copy to reflect modifications to the remote document as indicated by the
browser request; and
F) causing the remote document on the remote network device to be updated
to reflect the modifications made by the application program to the remote
document copy.
18. The method of claim 17, further comprising the step of the local
hypertext server formatting the browser request and directing the
formatted request to the local application program.
19. The method of claim 17, wherein the downloading step further comprises
the steps of:
A) receiving a transmission list from the remote network device to the
local computer system;
B) downloading onto the local computer system, in response to receipt of
the list, the remote document from the remote network device to produce
the remote document copy;
C) creating a local directory structure on the local computer system that
is substantially similar to a tree structure on the remote network device,
the tree structure on the remote network device including the remote
document; and
D) creating a local mapping table including data for identifying the
location of the remote document copy in the local directory structure.
20. The method of claim 17, further including the step of:
A) locating the remote document copy in the memory of the computer system
if the computer system is not connected to the network; and
B) executing the local application program, in response to a browser
request, to modify the remote document copy, the local application program
producing a modified remote document copy.
21. The method of claim 17, further including the step of:
displaying the modified remote document copy on a display device included
in the local computer system.
22. The method of claim 17, further including the step of:
transmitting the modified remote document copy to the remote network device
for reconciliation with the remote document.
23. A computer program product comprising:
A) a computer usable media having computer readable program code thereon
for processing a remote document stored in a network device remote from a
local computer system executing the computer readable program code, the
local computer system having a processor, a memory, and a browser, and
being connectable to the remote network device by a network, the computer
readable program code comprising:
B) program code for producing a browser request to modify the remote
document;
C) program code for intercepting the browser request;
D) program code, responsive to the browser request, for downloading a copy
of the remote document from the remote network device into the memory of
the computer system;
E) program code for causing a local hypertext server to convey information
in a template from the client browser to a local application program
executable by the processor of the local computer system;
F) program code for using the local application program in modifying the
remote document copy to reflect modifications to the remote document as
indicated by the browser request; and
G) program code for causing the remote document on the remote network
device to be updated to reflect the modifications made by the application
program to the remote document copy.
24. The computer program product of claim 23, further comprising program
code for causing the local hypertext server to format the browser request
and direct the formatted request to the local application program.
25. The computer program product 23, further comprising:
A) program code for receiving a transmission list from the remote network
device;
B) program code for downloading onto the local computer system, in response
to receipt of the list, the remote document from the remote network device
to produce the remote document copy;
C) program code for creating a local directory structure on the local
computer system that is substantially similar to a tree structure on the
remote network device, the tree structure on the remote network device
including the remote document; and
D) program code for creating a local mapping table including data for
identifying the location of the remote document copy in the local
directory structure.
26. The computer program product of claim 23, further including:
A) program code for locating the remote document copy in the memory of the
computer system if the computer system is not connected to the network;
and
B) program code for causing execution of the local application program, in
response to a browser request, to modify the remote document copy, the
local application program producing a modified remote document copy.
27. The computer program product of claim 23, further including:
program code for causing the modified remote document copy to be displayed
on a display device included in the local computer system.
28. The computer program product of claim 23, further including:
program code for causing the modified remote document copy to be
transmitted to the remote network device for reconciliation with the
remote document. |
|
 |
|
 |
Claims |
|
|
|
Description |
|
|
FIELD OF THE INVENTION
This invention relates generally to data transmission networks and, more
particularly, to using a common gateway interface for updating a copy of a
remote document stored in a local computer system.
BACKGROUND OF THE INVENTION
FIG. 1 shows a commonly used network arrangement in which a plurality of
local computer systems in a local area network (LAN) may access a
plurality of remote servers through the Internet. Each remote server may
include World Wide Web sites (web sites) that each include a plurality of
World Wide Web pages (web pages). Each local computer system may access
the remote web sites with web browser software, such as Netscape
Navigator.TM., available from Netscape Communications Corporation of
Mountain View, Calif.
The World Wide Web is a collection of servers on the Internet that utilize
the Hypertext Transfer Protocol (HTTP). HTTP is a known application
protocol that provides users with access to files (which can be in
different formats, such as text, graphics, images, sound, and video) using
a standard page description language known as Hypertext Markup Language
(HTML). HTML is used to transmit data and instructions between a remote
computer (server) and a local computer (client) in a form that is
understandable to the browser software on the client computer. More
particularly, HTML files may include many different types of format
descriptions that are translated and displayed by the client browser. One
such format description, for example, may describe a template for
receiving information that is intended to modify a selected database on a
remote server. A remote database application program, also stored on the
remote server, receives the information from the template and consequently
modifies the database. Information entered in the template by the client
browser typically is transferred into the database, via the database
application program, by an interface specification (interface) that is a
part of a hypertext server within the server. The interface format may be
any known interface format such as, for example, Common Gateway Interface
(CGI), Internet Server Application Program Interface (ISAPI, co-developed
by Microsoft Corporation and Process Software Company), or JAVA Applet
(developed by Sun Microsystems). CGI is discussed in more detail in "The
WWW Common Gateway Interface", version 1.1, in Internet draft form, dated
Feb. 16, 1996, by DRT Robinson.
As shown in simplified form in FIG. 2, the interface is a data
specification used by the hypertext server to format data transferred
between the client web browser and a database application program stored
on the server (application program). More particularly, the hypertext
server first extracts data submitted from the templates (by the client
browser), translates such data into the format of the interface
specification, and then transmits the translated data to the application
program to update the data stored in the database. After the database is
updated, the hypertext server may create a new HTML document reflecting
the modifications to the database. The new HTML document then may be
transmitted to the client, through the network, for review by the users of
the client.
Problems arise, however, when the client is not connected to the network
and thus, not able to access the database or the application program.
Specifically, the client can not modify the database until reconnected to
the network.
Accordingly, it would be desirable to have an apparatus and method that
enables a client to locally update a database, normally located on a
remote server, when the client is not connected to the network.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, the client computer
includes a local hypertext server, a local application program, and a
downloader for downloading a copy of a remote network document (remote
document copy), that is accessible by the local application program, onto
the client computer. When connected to the network, a user executes the
downloader to create the remote document copy on the client. When
disconnected, the user is able to access and modify the remote document
copy through the client browser in a manner that is similar to when the
client is connected to the network. Specifically, the client browser
conveys information in a template to the local application program through
the local hypertext server. The application program consequently modifies
the remote document copy in accordance with the information to be added to
the remote document copy. Upon reconnect to the network, the client
computer then updates the remote document to reflect the changes made by
the client computer during disconnect.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and advantages of the invention will be
appreciated more fully from the following further description thereof with
reference to the accompanying drawings wherein:
FIG. 1 is a block diagram of a generic network configuration that may be
used with the disclosed system;
FIG. 2 is a block diagram of a prior art network configuration using a
hypertext server with a common gateway interface at an origin server;
FIG. 2A is a block diagram of a client computer system suitable for use
with the disclosed system;
FIG. 3A is a block diagram of a prior art client computer;
FIG. 3B is a block diagram of the client computer shown in FIG. 3A with the
disclosed system;
FIG. 4 is an illustration showing the graphical user interface used to
initiate the disclosed system;
FIG. 5 is a block diagram of a network configuration that may utilize an
interface specification at a client computer;
FIG. 6 is a block diagram of the local interface specification on the
client computer;
FIG. 7 is a flow chart illustrating a process for downloading a database
from an origin server; and
FIG. 8 is a flow chart illustrating a process for accessing and modifying a
downloaded database.
FIG. 9 is a flow chart illustrating a process for downloading selected web
pages onto the client computer;
FIG. 10 is a flow chart illustrating a process of filtering web pages in
the CFHD system;
FIGS. 11A and 11B are flow charts illustrating a tree retrieval process
that may be utilized with the cache from here down (CFHD) system;
FIGS. 11C, 11D, and 11E are flow charts that collectively illustrate a
process of creating a local directory structure;
FIG. 12 is a flow chart illustrating a process for creating a local image
map mapping table;
FIG. 13 is an exemplary network configuration that may be used with the
autoupdate system;
FIG. 14 is a flow chart illustrating a process for initiating the
autoupdate process prior to disconnect;
FIG. 15 is a flow chart illustrating a process for updating an update copy
during disconnect;
FIG. 16 is a flow chart illustrating a process for updating a client copy
after reconnect;
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
FIG. 2A illustrates the system architecture for an exemplary client
computer system 200, such as an IBM THINKPAD 701.RTM. computer or Digital
Equipment Corporation HiNote.TM. computer, on which the disclosed network
access system (system) can be implemented. The exemplary computer system
of FIG. 2 is discussed only for descriptive purposes, however, and should
not be considered a limitation of the invention. Although the description
below may refer to terms commonly used in describing particular computer
systems, the described concepts apply equally to other computer systems,
including systems having architectures that are dissimilar to that shown
in FIG. 2.
The client computer 200 includes a central processing unit (CPU) 205, which
may include a conventional microprocessor, random access memory (RAM) 210
for temporary storage of information, and read only memory (ROM) 215 for
permanent storage. A bus controller 225 is provided for controlling bus
230, and an interrupt controller 235 is used for receiving and processing
various interrupt signals from the other system components.
Mass storage may be provided by diskette 242, CD-ROM 247, or hard disk 252.
Data and software may be exchanged with client computer 200 via removable
media, such as diskette 242 and CD-ROM 247. Diskette 242 is insertable
into diskette drive 241, which is connected to bus 230 by controller 240.
Similarly, CD-ROM 247 is insertable into CD-ROM drive 246, which is
connected to bus 230 by controller 245. Finally, the hard disk 252 is part
of a fixed disk drive 251, which is connected to bus 230 by controller
250.
User input to the client computer 200 may be provided by a number of
devices. For example, a keyboard 256 and a mouse 257 may be connected to
bus 230 by keyboard and mouse controller 255. An audio transducer 296,
which may act as both a microphone and a speaker, is connected to bus 230
by audio controller 297. It should be obvious to those reasonably skilled
in the art that other input devices, such as a pen and/or tablet and a
microphone for voice input, may be connected to client computer a 200
through bus 230 and an appropriate controller. DMA controller 260 is
provided for performing direct memory access to system RAM 210. A visual
display is generated by a video controller 265, which controls video
display 270.
Client computer 200 also includes a network adapter 290 that allows the
client computer 200 to be interconnected to a network 295 via a bus 291.
The network 295, which may be a local area network (LAN), a wide area
network (WAN), or the Internet, may utilize general purpose communication
lines that interconnect a plurality of network devices. FIG. 1 shows one
network arrangement for use with the system in which a plurality of local
computer systems (client computers 200) in a LAN are connected to the a
plurality of remote network sites 100 via the Internet. The remote sites
100 may be World Wide Web sites (web sites), stored on one or more remote
network devices, that each include a plurality of web pages. Each
accessible web site may be accessed with web browser software 399 (FIG.
3B), such as Netscape Navigator.TM., available from Netscape
Communications Corporation of Mountain View, California.
Client computer system 200 generally is controlled and coordinated by
operating system software, such as the WINDOWS 95.RTM. operating system
(available from Microsoft Corp., Redmond, Wash.). Among other computer
system control functions, the operating system controls allocation of
system resources and performs tasks such as process scheduling, memory
management, networking and I/O services.
FIG. 3A shows in more detail a prior art configuration of the client
computer 200 connected to a network. Specifically, the client computer 200
includes the network adapter 290, the operating system 292, a network
protocol stack 393 (e.g., Microsoft TCP/IP.RTM., from Microsoft Corp.),
and the browser 399. The browser 399 transmits requests to the network
stack 393, which processes the requests and transmits them to the network
295 via the network adapter 290 and operating system 292. Similarly,
responses from the network 295 are received by the network stack 393, via
the network adapter 290 and operating system 292, and then provided to the
browser 399. When downloading a remote web page from a remote server, for
example, the browser 399 first transmits a request for the web page, with
the web page Uniform Resource Locator ("URL"), to the network stack 393.
The network stack 393 responsively locates the a remote server and then
transmits the request to the remote server via the operating system 292
and network adapter 290. The web page then is transmitted to the network
adapter 290, via the network 395, and received by the network stack 393.
The retrieved web page then is provided to the browser 399 for display on
the client computer 200.
Improving on the configuration shown above in FIG. 3A, FIG. 3B shows a
preferred embodiment of the system. Specifically, an interceptor 394 is
added to the client computer 200 to intercept transmissions between the
browser 399 and the network stack 393. Such transmissions may be a request
by the browser 399 to access a web page on a remote server. Upon receipt
of such transmissions, the interceptor 394 provides improved functionality
for the client computer 200. Among the improvements is the capability of
accessing locally stored web pages through the browser 399 without
requiring that the user either preconfigure the browser 399, or notify the
browser 399 that the client computer 200 is disconnected from the network
295.
The system thus includes the interceptor 394 and a mechanism for
ascertaining if the client computer 200 is connected to the network 295.
If the client computer 200 is connected to the network 295, the address
(ie., URL) of the web page is determined from the request. A fetch command
then is transmitted to the remote server having the web page, thereby
causing the client computer 200 to download the web page from the remote
server. Conversely, if the client computer 200 is not connected to the
network 295, the system includes a mechanism for locating the web page in
the memory of the client computer 200 if such web page already had already
been downloaded. The downloaded web page preferably is stored in a local
directory structure constructed as discussed below with reference to FIGS.
11C, 11D, and 11E.
Use of the interceptor 394 thus enables the user to access a web page via
the browser 399, during disconnect, in a manner similar to that when the
client computer 200 is connected to the network 295. The user thus may
access the downloaded web page without knowing if the client computer 200
is connected to or disconnected from the network 295.
As shown schematically in FIG. 5, another aspect of the system
automatically enables the client computer 200 to first download a copy 504
of a remote network document 506 (e.g., a database) from an origin server
510 ("origin server 510"), and then modify the (database) copy 504 while
disconnected from the network 295. Upon reconnect to the network 295, the
client computer 200 then updates the remote (database) document 506 to
reflect the changes made by the client computer 200 during disconnect.
This enables the user to modify such a database during disconnect while
automatically ensuring that such modifications will be made to the remote
(database) document 506 upon re-connect.
To that end, as shown in FIG. 5, the client computer 200 may include a
local hypertext server 500 for formatting data received from the
interceptor 394 into a selected interface format, a local application
program 502, which is compatible with the database and receives formatted
information from the hypertext server, and a downloader 398 for
downloading, prior to disconnect, a local copy 504 of the database 506
onto the client computer 200 from the remote network device. The local
application program 502 is a substantial duplicate of the application
program 512 on the origin server 510. In addition, program 502 may be
either downloaded with the local copy 504, preloaded into the memory of
the client computer 200, or otherwise accessible by the client computer
200 during disconnect. The interface format may be any known interface
format such as, for example, Common Gateway Interface (CGI), Internet
Server Application Program Interface (ISAPI, co-developed by Microsoft
Corporation and Process Software Company), or JAVA Applet (developed by
Sun Microsystems). CGI is discussed in more detail in "The WWW Common
Gateway Interface", version 1.1, in Internet draft form, dated Feb. 16,
1996, by DRT Robinson.
Accordingly, during disconnect, requests from the browser 399 to modify the
database are intercepted by the interceptor 394. Such request may include
data from a template. The interceptor 394 responsively determines that the
client computer 200 is disconnected from the network, and then directs the
request to the local hypertext server. The local hypertext server
responsively translates the request and transfers the data (from the
template) to the local application program 502 to modify the locally
stored database copy. This process is done completely while disconnected
from the network 295 and thus, does not require access to the hypertext
server on the origin server 510. Moreover, this process is a background
process and thus, does not interrupt the execution of the browser or other
application programs on the system. The modifications to the database copy
504 then may be made to the database 506 on the origin server 510 upon
reconnect.
More particularly, FIG. 6 is a block diagram of a preferred embodiment of
the local hypertext server 500 stored on the client computer 200 in
relation to the interceptor 394. The local hypertext server 500 may
include the following elements:
an engine 604 for performing the interfacing functions of the interface;
a directory mapping table 606 for storing the location of the database copy
504 within the directory structure of the client local computer;
a data pump 608 for downloading the database 506 from the origin server
510; and
a cache control 610 for causing the data pump to download the database from
the origin server 510 to the client computer 200.
The interceptor 394 may include the following elements:
a redirector 600 for receiving browser requests and directing specified
requests to the local hypertext server; and
a connection manager 602 for determining if the client computer 200 is
connected to the network 295.
The function of each of these elements are more fully understood with
reference to FIGS. 7 and 8. FIG. 7 is a flow chart illustrating a process
for downloading the database 506 from the remote network device, and FIG.
8 is a flow chart illustrating a process for accessing and modifying the
downloaded database copy 504 of the database.
With reference to FIG. 7, the process begins at step 700 in which the
browser 399 on the client computer 200 requests that the database 506 be
downloaded from the origin server 510. This request is intercepted by the
interceptor 394, which determines if the client computer 200 is connected
to the network. The function of the interceptor 394 is effected here by
the redirector 600 and the connection manager 602. At step 702, the
connection manager 602 determines if the client computer 200 is connected
to the network 295. If disconnected, the process ends because the database
506 cannot be downloaded. If connected to the network 295, the interceptor
394 transmits the request to the origin server 510. The origin server 510
responds at step 706 by transmitting a list, having a "mime" header, to
the client computer 200. The list then is transmitted to the cache control
610 (step 708) that first determines from the list which databases will be
downloaded, and then causes the data pump 608 to begin downloading a copy
of each of the databases in the list. After the database copy 504 is
downloaded, the cache control 610 creates a directory mapping table (if
not already created) having fields "URL" and "location in local directory
structure" (step 710). The cache control 610 then adds data to the
directory mapping table, thereby providing the information for creating a
client directory structure, if necessary, in the client computer 200 that
is similar to the hierarchical tree structure on the origin server 510.
The client directory structure may be created by conventional means.
Once the database copy 504 is downloaded into the client directory
structure and its location is stored in the directory mapping table, the
client may access and modify the database copy 504 with the client browser
399 while disconnected from the network 295. FIG. 8 thus shows a process
of accessing and modifying the downloaded database copy 504 in the client
computer 200 when disconnected. Specifically, after data is entered into
the templates, the browser 399 first requests access to the database 506
via the interceptor 394 and the redirector 600 (step 800). The redirector
then queries the connection manager 602 at step 802 to determine if the
client computer 200 is connected to the network 295. If connected to the
network 295, the database 506 on the origin server 510 is accessed and
modified, by conventional means, over the network 295 (step 804).
If the client computer 200 is not connected to the network 295, the
redirector 600 accesses the mapping table 606 to ascertain the location of
the database and local application program 502 in the client directory
structure (step 806). The redirector 600 then transmits the location of
the local application program 502, the database copy 504, and the data to
modify the database copy 504 to the local engine 604 at step 808. The
local engine 604 then locates the database copy 504 and local application
program 502, translates the data, and then transmits the translated data
to the local application program 502, (step 810). The application program
502 then modifies the database at step 812 and responsively sends an HTML
response to the browser 399 reflecting the modifications (step 814). Upon
reconnect, the data pump 608 may upload the modified database to the
origin server 510 to reflect the changes made in the database.
In the preferred embodiment, which is implemented using CGI, the cache
control 610 accesses a plurality of functions to modify the mapping table
606. Among those functions are:
addCGlcacheEntry(CString cURL, CString cDirectory);
removeCGlcacheEntry(CStringcURL);
mapCache(CString cURL, CString & cResult);
findCGIcasheEntry(CStringcURL);
getCGIcacheEntry(intnIndex, CString cURL, CString & cDirectory);
getCGIcacheCount();
readCGIcacheList(); and
writeCGIcacheList();
Each function is briefly discussed below:
The function "add CGIcache Entry" creates a new directory entry on the
client computer 200 that represents a remote (CGI) application, given the
URL string and the root directory. It is assumed that the full root
directory path is specified in the cDirectory parameter passed to this
routine, and that cURL is the standard reference to the application on the
remote server. An example of the input parameter for cURL could be
"//www.server1.com/.about.alias/aca.about.1/dispatch.cgi", where
www.serverl.com is the remote address of the server,
"/.about.alias/aca.about.1/" is a directory specification on the server
and "dispatch.cgi" is the CGI application to run. An example of the input
parameter for cDirectory might be
"C:.backslash.WIN32APP.backslash.WGWF.backslash.", which identifies the
root directory for all mapped entries. The result of this function is that
an entry is created in the directory mapping table, and an associated
directory is created that is used to contain files required to locally
download the remote application specified. The database mapping created
for the above example, having a URL of:
"HTTP://www.server1.com/.about.alias/aca.about.1/dispatch.cgi"
maps to the directory:
"C:.backslash.WIN32APP.backslash.WGWF.backslash.WWW.SERVER1.
COM.backslash..about.ALIAS.backslash.ACA.about.I.backslash.."
on the local system when disconnected.
The function "removeCGlcacheEntry" enables the cache control 610 to remove
a "URL to directory" mapping in the directory mapping table given cURL,
where cURL is the specific URL map entry. If there is no matching URL, the
request returns an error. If a URL exists in the database mapping table,
it is removed.
The function "mapCache" is used by the redirector to search the directory
mapping table for matching the passed cURL to an existing entry. If a
match is found, the directory mapping is returned using cResult. This
routine is used when the client computer 200 is disconnected to determine
if the remote request can be satisfied by a stored CGI entry. If cResult
returns non-zero, an entry exists and the request is directed to the
engine with a SCRIPT.sub.-- NAME environment parameter pointing to the
local application as a result of this mapping. An example of the input
parameter for the URL could be
"//www.server1.com/-alias/aca-1/dispatch.cgi." If a match existed, an
example of the output parameter for cResult might be
"C:.backslash.WIN32APP.backslash.WGWF.backslash.WWW.SERVER1.COM.backslash.-
ALIAS.backslash.ACA-1.backslash.DISPATCH.CGI." The URL has been mapped to a
local directory, and the executable file DISPATCH.CGI has been parsed and
appended to the directory specification.
The functions "findCGIcasheEntry," "getCGIcacheEntry" and
"getCGlcacheCount" are enumeration routines used by the graphical user
interface of the application to display and manage information in the
directory mapping table.
The functions "readCGlcacheList" and "writeCGlcacheList" are low level
routines used to read and write the basic objects used in the directory
mapping table.
After the database copy 504 is modified and the client is reconnected to
the network 295, the client computer 200 may access the server again and
modify the database to reflect the data added, removed, or modified during
disconnect (database transaction). This may be done by conventional
methods, such as by means of a reconciliation engine to update the
database, or by directly overwriting the database on the origin server
510.
When the preferred embodiment of this aspect of the system is in use, a
user of the client computer 200 connects to the origin server 510, via the
network 295, and accesses a application program associated with the
database. The interface associated with that application program may
include a "download" button which, when selected by the client user,
causes the database and associated origin server 510 directory structure
to be downloaded from the origin server 510 to the client computer 200. A
status bar may be displayed by the client computer 200 during the
download. The user then may disconnect from the network 295 and modify the
database copy 504 via the local application and the browser 399 in a
manner that is substantially identical (to the user) to when the client
computer 200 is connected to the network. Access through the browser 399
is necessary in all CGI application programs, for example, designed for
the World Wide Web because such applications frequently do not have a user
interface. Specifically, the CGI application "standard in" (a part of each
application program that specifies from where data may be received; | | |
