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Claims  |
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I claim:
1. A web server computer apparatus comprising:
a central processing unit;
a memory coupled to the central processing unit, the memory including:
a plurality of pages, the plurality of pages including indicia of dynamic
data to be retrieved from a plurality of data sources for insertion into
at least one of the plurality of pages; and
at least one web server program, the web server program processing the
indicia to retrieve the dynamic data from the plurality of data sources.
2. The computer apparatus of claim 1 further comprising:
a plurality of language processors, each language processor being coupled
to at least one of the plurality of data sources, the language processor
processing the indicia to retrieve the dynamic data from the corresponding
data source;
a configuration file containing configuration data for indicating the
correspondence between the indicia and the plurality of language
processors;
at least one transaction processor, the transaction processor reading the
configuration file and processing a selected one of the plurality of pages
according to the configuration data, the transaction processor receiving
from the corresponding language processor the dynamic data and placing the
dynamic data within the data for the selected page.
3. The computer apparatus of claim 2 wherein the selected page is selected
using a Uniform Resource Locator (URL).
4. The computer apparatus of claim 2 wherein the selected page is a
hypertext markup language (HTML) page.
5. A program product comprising:
(A) a web server program, the web server program including:
a plurality of pages, the plurality of pages including indicia of dynamic
data to be retrieved from a plurality of data sources for insertion into
at least one of the plurality of pages; and
at least one web server program, the web server program processing the
indicia to retrieve the dynamic data from the plurality of data sources.
6. The program product of claim 5 further comprising:
a plurality of language processors, each language processor being coupled
to at least one of the plurality of data sources, the language processor
processing the indicia and formulating therefrom at least one query to
retrieve the dynamic data from the corresponding data source;
a configuration file containing configuration data for indicating the
correspondence between the indicia and the plurality of language
processors;
at least one transaction processor, the transaction processor reading the
configuration file and processing a selected one of the plurality of pages
according to the configuration data, the transaction processor receiving
from the corresponding language processor the dynamic data and placing the
dynamic data within the data for the selected page.
7. The program product of claim 6 wherein the selected page is selected
using a Uniform Resource Locator (URL).
8. The program product of claim 6 wherein the selected page is a hypertext
markup language (HTML) page.
9. The program product of claim 5 wherein the signal bearing media
comprises recordable media.
10. The program product of claim 5 wherein the signal bearing media
comprises transmission media.
11. A web server computer apparatus comprising:
a central processing unit;
a memory coupled to the central processing unit, the memory including:
at least one macro file containing data for a plurality of pages, at least
one of the plurality of pages including at least one function call to
retrieve dynamic data from at least one data source;
at least one language processor coupled to the at least one data source,
the language processor processing the at least one function call to
retrieve the dynamic data from the at least one data source;
a configuration file containing configuration data for indicating the
correspondence between the at least one function call and the at least one
language processor;
at least one transaction processor, the transaction processor reading the
configuration file and processing the data in the macro file corresponding
to a selected one of the plurality of pages according to the configuration
data, the transaction processor receiving from the language processor the
dynamic data and placing the dynamic data within the data for the selected
page.
12. The computer apparatus of claim 11 further comprising a plurality of
language processors and a plurality of data sources, wherein each language
processor processes the at least one function call for the dynamic data
that resides in at least one data source.
13. The computer apparatus of claim 12 wherein the function call identifies
a need for dynamic data.
14. The computer apparatus of claim 12 wherein the selected page is
selected using a Uniform Resource Locator (URL).
15. The computer apparatus of claim 12 wherein the selected page is a
hypertext markup language (HTML) page.
16. A program product comprising:
(A) a web server program, the web server program including:
(1) at least one macro file containing data for a plurality of hypertext
markup language (HTML) pages, at least one of the plurality of pages
including at least one function call to retrieve dynamic data from at
least one data source;
(2) at least one language processor coupled to the at least one data
source, the language processor processing the at least one function call
to retrieve the dynamic data from the at least one data source; and
(3) a configuration file containing configuration data for indicating the
correspondence between the at least one function call and the at least one
language processor; and
(4) at least one transaction processor, the transaction processor reading
the configuration file and processing the data in the macro file
corresponding to a selected one of the plurality of pages according to the
configuration data, the transaction processor receiving from the language
processor the dynamic data and placing the dynamic data within the data
for the selected page;
and
(B) signal bearing media bearing the web server program.
17. The program product of claim 16 wherein the signal bearing media
comprises recordable media.
18. The program product of claim 16 wherein the signal bearing media
comprises transmission media.
19. The program product of claim 16 wherein the selected page is a
hypertext markup language (HTML) page.
20. A computer-implemented method for processing at least one request for
at least one page, the method including the steps of:
providing a plurality of pages, the pages including indicia of dynamic data
to be retrieved from a plurality of data sources for insertion into at
least one of the plurality of pages;
the request selecting at least one page to be processed;
providing a web server program in a memory of a web server computer
apparatus, the web server computer apparatus executing the web server
program, and in response thereto, performing the steps of:
determining which of the plurality of pages is the selected page;
processing any indicia within the selected page to retrieve the dynamic
data from the plurality of data sources; and
inserting the dynamic data into the selected page.
21. The computer-implemented method of claim 20 wherein the selected page
is a hypertext markup language (HTML) page.
22. The computer-implemented method of claim 20 wherein the request
comprises a Uniform Resource Locator (URL).
23. A computer-implemented method for processing at least one request for
at least one page, the method including the steps of:
providing at least one language processor capable of processing queries in
a particular language;
providing at least one data source coupled to the at least one language
processor, each data source corresponding to at least one language
processor;
determining a plurality of function calls corresponding to each language
processor;
the request selecting at least one page to be processed;
determining if the selected page contains at least one of the plurality of
function calls corresponding to dynamic data;
if the selected page contains a function call corresponding to dynamic
data, performing the steps of:
a selected language processor corresponding to the function call processing
the function call to generate a query to retrieve the dynamic data from
the at least one data source that corresponds to the selected language
processor; and
inserting the dynamic data into the selected page.
24. The computer-implemented method of claim 23 further comprising the step
of sending the selected page containing the dynamic data to a user that
performed the step of selecting the at least one page to be processed by
providing a Uniform Resource Locator (URL).
25. The computer-implemented method of claim 23 wherein each function call
corresponds to at least one of the language processors.
26. The computer-implemented method of claim 23 wherein the step of
determining the plurality of function calls for each language processor
includes the step of reading a configuration file that contains
configuration data that correlates each language processor to a plurality
of the function calls.
27. The computer-implemented method of claim 23 wherein the selected page
is a hypertext markup language (HTML) page.
28. The computer-implemented method of claim 23 wherein the request
comprises a Uniform Resource Locator (URL).
29. A program product comprising:
(A) a web server program, the web server program including:
(1) at least one macro file containing data for a plurality of hypertext
markup language (HTML) pages, at least one of the plurality of HTML pages
including at least one function call to retrieve dynamic data from a
plurality of data sources;
(2) a plurality of language processors coupled to the plurality of data
sources, the language processor processing the at least one function call
to retrieve the dynamic data from the corresponding data source;
(3) a configuration file containing configuration data for indicating the
correspondence between the at least one function call and the at least one
language processor; and
(4) at least one transaction processor, the transaction processor reading
the configuration file and processing the data in the macro file
corresponding to a selected one of the plurality of HTML pages according
to the configuration data, the transaction processor receiving from at
least one of the plurality of language processors the dynamic data and
placing the dynamic data within the data for the selected HTML page;
and
(B) signal bearing media bearing the web server program.
30. The program product of claim 29 wherein the signal bearing media
comprises recordable media.
31. The program product of claim 29 wherein the signal bearing media
comprises transmission media.
32. A computer-implemented method for displaying a selected hypertext
markup language (HTML) page on a user workstation, the method including
the steps of:
providing the user workstation executing a web browser application;
providing a web server computer executing a web server application, the web
server computer including:
a central processing unit;
a memory coupled to the central processing unit, the memory including:
at least one macro file containing data for a plurality of HTML pages, at
least one of the plurality of HTML pages including at least one function
call to retrieve dynamic data from at least one data source;
at least one language processor coupled to the at least one data source,
the language processor processing the at least one function call to
retrieve the dynamic data from the corresponding data source;
a configuration file containing configuration data for indicating the
correspondence between the at least one function call and the at least one
language processor;
at least one transaction processor, the transaction processor reading the
configuration file and processing the data in the macro file corresponding
to a selected one of the plurality of HTML pages according to the
configuration data, the transaction processor receiving from the language
processor the dynamic data and placing the dynamic data within the data
for the selected HTML page;
the transaction processor reading the configuration file;
determining the correspondence between each function call and each language
processor;
determining if the selected HTML page contains at least one function call
for dynamic data;
if the selected HTML page contains the at least one function call for
dynamic data, performing the steps of:
a selected language processor corresponding to the function call processing
the function call to generate a query to retrieve the dynamic data from
the at least one data source that corresponds to the selected language
processor;
transferring the dynamic data from the selected language processor to the
transaction processor;
the transaction processor inserting the dynamic data into the selected HTML
page; and
the web server computer sending the selected HTML page containing the
dynamic data to the user workstation.
33. The computer-implemented method of claim 32 wherein the request
comprises a Uniform Resource Locator (URL). |
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Claims |
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Description |
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FIELD OF THE INVENTION
This invention generally relates to network servers, such as web servers on
the Internet. More specifically, this invention relates to a mechanism for
processing queries for dynamic data within a web page.
BACKGROUND OF THE INVENTION
The development of the EDVAC computer system of 1948 is often cited as the
beginning of the computer era. Since that time, computer systems have
evolved into extremely sophisticated devices, and computer systems may be
found in many different settings. The widespread proliferation of
computers prompted the development of computer networks that allow
computers to communicate with each other. With the introduction of the
personal computer (PC), computing became accessible to large numbers of
people. Networks for personal computers were developed that allow
individual users to communicate with each other.
One significant computer network that has recently become very popular is
the Internet. The Internet grew out of this proliferation of computers and
networks, and has evolved into a sophisticated worldwide network of
computer systems. A user at an individual PC (i.e., workstation) that
wishes to access the Internet typically does so using a software
application known as a web browser. A web browser makes a connection via
the Internet to other computers known as web servers, and receives
information from the web servers that is displayed on the user's
workstation. Information displayed to the user is typically organized into
pages that are constructed using a specialized language called Hypertext
Markup Language (HTML). The first web pages contained static data, meaning
that the data on the page would be the same regardless of who accessed the
page or when it was accessed. More recent web pages include dynamic data,
which means that data on certain portions of the page is subject to
change. One example of dynamic data is displaying stock market or other
data that changes periodically. When accessing a page that includes
dynamic data, the web server must know how and from what data source to
retrieve the needed information for dynamic insertion into the HTML page.
Web servers that allow for dynamic data to be inserted into an HTML page
typically have special software for processing the HTML page. The special
software may be termed a "transaction processor", which processes an HTML
page and handles special function calls or queries (i.e., transactions)
that require dynamic data to be inserted into the page. These web servers
typically have hard-coded transaction processors that detect a specific
type of query for dynamic data within the HTML page data, and that perform
the necessary accesses to a dedicated data source to retrieve the dynamic
data. The retrieved data is then inserted into the HTML page, thereby
allowing the dynamic data to be displayed to the user within the HTML
page. If more than one data source is present, or if more than one type of
data source is used, the web server must be manually reprogrammed to
accommodate the specific number and types of data sources to be accessed.
As the number of Internet users, providers, and web servers continues to
rapidly expand, it will become increasingly important for a web server to
be able to accommodate new sources of dynamic data in an efficient manner.
Without improvements in the manner dynamic data for HTML pages is
processed, the adaptation of a web server to accommodate new data sources
will continue to be an impediment to web server efficiency and
performance.
SUMMARY OF THE INVENTION
A web server according to the present invention includes a transaction
processor that reads a configuration file to determine how to handle
incoming queries to dynamic data sources. A number of language processors
are provided for handling the possible different types of queries for
dynamic data. When a query within a web page is encountered, the
transaction processor determines from the configuration data which
language processor will handle this specific type of query, and passes the
query to the appropriate language processor. The language processor
processes the query, obtains the dynamic data from the appropriate data
source, and passes the data back to the transaction processor. The
transaction processor then inserts the dynamic data into the web page to
be sent to the requesting user's web browser.
The foregoing and other objects, features and advantages of the invention
will be apparent from the following more particular description of
preferred embodiments of the invention, as illustrated in the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred exemplary embodiments of the present invention will
hereinafter be described in conjunction with the appended drawings, where
like designations denote like elements, and:
FIG. 1 is a block diagram of a web server computer system in accordance
with the present invention;
FIG. 2 is a block diagram of a typical Internet connection;
FIG. 3 is a block diagram of a web server mechanism that accommodates
dynamic data in a web page;
FIG. 4 is a block diagram of the contents of the main memory in the web
server computer system of FIG. 3;
FIG. 5 is a flow diagram of the steps that are taken to use the web server
mechanism of FIG. 3;
FIG. 6 is a block diagram of a web server mechanism according to the
preferred embodiment;
FIG. 7 is a block diagram of the contents of the main memory in the web
server computer system of FIGS. 1 and 6;
FIG. 8 is a flow diagram of the steps that are taken to use the web server
mechanism of FIG. 6; and
FIG. 9 is a block diagram showing some of the features of the macro file
and configuration file of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Overview
The method and apparatus of the present invention has particular
applicability to web servers on the Internet. For those individuals who
are not familiar with the Internet, the world-wide web, web servers, and
web browsers, a brief overview of these concepts is presented here.
An example of a typical Internet connection is shown in FIG. 2. A user that
wishes to access information on the Internet 170 typically has a computer
workstation 200 that executes an application program known as a web
browser 210. Under the control of web browser 210, workstation 200 sends a
request for a web page over the Internet. Web page data can be in the form
of text, graphics and other forms of information. Each web server on the
Internet has a known address which the user must supply to the web browser
in order to connect to the appropriate web server. Because web server 220
can contain more than one web page, the user will also specify in the
address which particular web page he wants to view on web server 220. A
web server computer system 220 executes a web server application 122,
monitors requests, and services requests for which it has responsibility.
When a request specifies web server 220, web server application 122
generally accesses a web page corresponding to the specific request, and
transmits the page to the user's workstation 200.
Web Pages
A web page is primarily visual data that is intended to be displayed on the
monitor of user workstation 200. Web pages are generally written in
Hypertext Markup Language (HTML). When web server 220 receives a web page
request, it will build a web page in HTML and send it off across the
Internet 170 to the requesting web browser 210. Web browser 210
understands HTML and interprets it and outputs the web page to the monitor
of user workstation 200. This web page displayed on the user's screen may
contain text, graphics, and links (which are addresses of other web
pages.) These other web pages (i.e., those represented by links) may be on
the same or on different web servers. The user can go to these other web
pages by clicking on these links using a mouse or other pointing device.
This entire system of web pages with links to other web pages on other
servers across the world is known as the "World Wide Web".
Static and Dynamic Data in Web Pages
As discussed in the Background section, when this web technology began, web
pages contained only static data. For example, a web page displaying a
company's balance sheet for a given quarter is static, meaning that the
information is not going to change and can therefore be placed directly
into the page. Later methods were developed to introduce dynamic data into
web pages. For example, if a web page displaying current stock market
activity is to be developed, then dynamic data showing current market
figures must be incorporated. This dynamic data is generally available in
a database or some other data source. The dynamic data is retrieved from
the data source when the user requests the web page, thereby assuring that
the dynamic data displayed on the requested web page is current.
The remainder of this specification describes how the present invention
improves the flexibility and power of a web server by providing a simple
way for allowing the web server to access dynamic data from new data
sources. Those skilled in the art will appreciate that the present
invention applies equally to any type of web server that accesses dynamic
data for an HTML page, regardless of the specific configuration of the web
server or the data source.
DETAILED DESCRIPTION
Referring to FIG. 1, a computer system 100 in accordance with the present
invention includes a central processing unit (CPU) 110, a main memory 120,
a mass storage interface 140, and a network interface 150, all connected
by a system bus 160. Those skilled in the art will appreciate that this
system encompasses all types of computer systems: personal computers,
midrange computers, mainframes, etc. Note that many additions,
modifications, and deletions can be made to this computer system 100
within the scope of the invention. Examples of this are a computer
monitor, input keyboard, cache memory, and peripheral devices such as
printers. The present invention is operating as a web server, which is
generally implemented with a personal or midrange computer.
CPU 110 can be constructed from one or more microprocessors and/or
integrated circuits. CPU 110 executes program instructions stored in main
memory 120. Main memory 120 stores programs and data that the computer may
access. When computer system 100 starts up, CPU 110 initially executes the
operating system 134 program instructions. Operating system 134 is a
sophisticated program that manages the resources of the computer system
100. Some of these resources are the CPU 110, main memory 120, mass
storage interface 140, network interface 150, and system bus 160.
Referring to FIGS. 1 and 7, main memory 120 includes a web server
application 122, a transaction processor 124, one or more macro files 126,
a configuration file 128, one or more language processors 130, an
operating system 134, one or more application programs 136, and program
data 138. Application programs 136 are executed by CPU 110 under the
control of operating system 134. Application programs 136 can be run with
program data 138 as input. Application programs 136 can also output their
results as program data 138 in main memory. In the present invention, a
computer system 100 is operating as a web server, so CPU 110 executes,
among other things, web server application 122. Transaction processor 124
is a program that processes an HTML page stored in one or more macro files
126. When transaction processor 124 is initialized, it reads configuration
file 128 to correlate different types of queries to different language
processors 130. When a query to dynamic data is found in a page,
transaction processor 124 determines from the configuration data (read
from the configuration file) which language processor 130 it should call
to process the query. The appropriate language processor 130 then queries
a data source, such as a memory or a database, to retrieve the dynamic
data. Language processor 130 passes the dynamic data to transaction
processor 124, which inserts the dynamic data into the HTML data for the
selected page.
Mass storage interface 140 allows computer system 100 to retrieve and store
data from auxiliary storage devices such as magnetic disks (hard disks,
diskettes) and optical disks (CD-ROM). These mass storage devices are
commonly known as Direct Access Storage Devices (DASD), and act as a
permanent store of information. One suitable type of DASD is a floppy disk
drive 180 that reads data from and writes data to a floppy diskette 186.
The information from the DASD can be in many forms. Common forms are
application programs and program data. Data retrieved through mass storage
interface 140 is usually placed in main memory 120 where CPU 110 can
process it.
While main memory 120 and DASD device 180 are typically separate storage
devices, computer system 100 uses well known virtual addressing mechanisms
that allow the programs of computer system 100 to behave as if they only
have access to a large, single storage entity, instead of access to
multiple, smaller storage entities (e.g., main memory 120 and DASD device
185). Therefore, while certain elements are shown to reside in main memory
120, those skilled in the art will recognize that these are not
necessarily all completely contained in main memory 120 at the same time.
It should be noted that the term "memory" is used herein to generically
refer to the entire virtual memory of computer system 100.
Network interface 150 allows computer system 100 to send and receive data
to and from any network the computer system may be connected to. This
network may be a local area network (LAN), a wide area network (WAN), or
more specifically the Internet 170. Suitable methods of connecting to the
Internet include known analog and/or digital techniques, as well as
networking mechanisms that are developed in the future. Many different
network protocols can be used to implement a network. These protocols are
specialized computer programs that allow computers to communicate across a
network. TCP/IP (Transmission Control Protocol/Internet Protocol), used to
communicate across the Internet, is an example of a suitable network
protocol.
System bus 160 allows data to be transferred among the various components
of computer system 100. Although computer system 100 is shown to contain
only a single main CPU and a single system bus, those skilled in the art
will appreciate that the present invention may be practiced using a
computer system that has multiple CPUs and/or multiple buses. In addition,
the interfaces that are used in the preferred embodiment may include
separate, fully programmed microprocessors that are used to off-load
compute-intensive processing from CPU 110, or may include I/O adapters to
perform similar functions.
At this point, it is important to note that while the present invention has
been (and will continue to be) described in the context of a fully
functional computer system, those skilled in the art will appreciate that
the present invention is capable of being distributed as a program product
in a variety of forms, and that the present invention applies equally
regardless of the particular type of signal bearing media used to actually
carry out the distribution. Examples of signal bearing media include:
recordable type media such as floppy disks (e.g., 186 of FIG. 1) and CD
ROM, and transmission type media such as digital and analog communications
links.
The remainder of this specification will describe two different methods and
associated computer systems for processing dynamic data in web pages. The
first is a method that IBM developed using a program that runs on the web
server called DB2WWW, Release 1, with respect to the configuration
disclosed in FIGS. 3-5, and constitutes an alternative embodiment of the
invention. The second method and the associated computer system is the
preferred embodiment of the present invention as disclosed in FIGS. 6-9.
Any of the programs executing on a web server to accomplish either of
these implementations (e.g., transaction processors 124, 224 and language
processors 130, 230) are referred to generically herein as web server
programs.
In the present invention a computer system 100 is being operated as a web
server. To do so, a web server application 122 is executed by CPU 110.
Other application programs 136 may be run simultaneously on computer
system 100 assuming that operating system 134 is a multi-tasking operating
system. Web servers are generally connected to the Internet 170. As has
been discussed, the Internet is a well known computer network that spans
the world and is shared by millions of computers. There are many web
servers on the Internet. Each computer linked to the Internet has its own
unique address to enable it to communicate back and forth across the
network with other computers. Many different types of data can be sent
along the Internet. Examples are electronic mail, program data, digitized
voice data, computer graphics, and web pages. The present invention
extends to the transmission of any type of data that may have one or more
components that are dynamically changed or updated prior to transmission
to the user, but is described herein by way of illustration in the context
of web pages that contain dynamic data.
When dynamic data needs to be displayed on a web page, certain steps must
be taken that are not required for static web pages. One particular
implementation for handling dynamic data in web pages is illustrated in
FIGS. 3 and 4, which illustrates an implementation developed at IBM. Web
server 220 includes a web server application 122, one or more macro files
126, and a transaction processor 224 with a hard-coded language processor
230. Transaction processor 224 represents Release 1 of an IBM web server
program known as DB2WWW. Release 1 was designed specifically to process
SQL (Structured Query Language) database queries for dynamic data in web
pages. SQL is a well known database format. The most salient portions of
main memory for web server 220 are shown in FIG. 4. The operation of web
server 220 may best be understood with reference to the flow diagram of
FIG. 5.
A user at workstation 200 executes web browser application 210 to access
the Internet 170. A user requests a web page by sending a Uniform Request
Locator (URL) across the Internet 170 (step 510). URL is a well known
protocol used to address resources on the World Wide Web. A URL contains
the complete Internet address of a web server plus additional parameters
which specify the desired web page. The following is an example of a URL
that will be used to illustrate the function of the system of FIGS. 3 and
4:
http://www.abcxyz.com/cgi-bin/db2www.exe/wbp1.fil/2ndpage
where:
http:// is the standard syntax to tell the web browser that what follows is
a web page address.
www.abcxyz.com is the web server address.
/cgi-bin/db2www.exe tells the web server to execute and transfer control to
program ctb2www.exe and pass any remaining part of the URL as parameters.
/cgi-bin refers to the Common Gateway Interface which is a well known web
server interface that allows a web server application to invoke other
programs to help with the processing of web page requests. In this example
for Release 1 of DB2WWW, we assume that db2www.exe is the name of the
transaction processor program that is executing on web server 220. In this
context, /wbp1.fil/2ndpage are the parameters that are passed to
transaction processor program db2www.exe. The transaction processor
program will interpret the first parameter "wbp1.fil" as the macro file
name and the second parameter "2ndpage" as the HTML section name within
the macro file "wbp1.fil."
The user can send a URL by "clicking" with a mouse on a web page link, or
the user can enter the entire URL address manually in the web browser. The
URL is sent and travels across the Internet 170, contacting the web server
220 (as specified in the URL) (step 512).
When web server application 122 receives the URL from user workstation 200
that includes the cgi-bin parameter, web server application 122 calls
transaction processor 224 and transfers control to it (step 514).
Transaction processor 224 then processes the parameters passed to it
(e.g., wbp1.fil and 2ndpage) to find the appropriate HTML section
(2ndpage) in macro file 126 (wbp1.fil) that corresponds to the requested
web page (step 516). Transaction processor 224 then begins processing the
selected HTML section in macro file 126 to build the web page (step 520).
The next step is to determine whether the selected web page contains
dynamic data. For Release 1 of DB2WWW, the presence of dynamic data is
determined by scanning the HTML section for SQL queries for dynamic data.
If an SQL query for dynamic data exists in the HTML section being
processed (step 522=YES), then the SQL query is located (step 534), then
passed to language processor 230 (step 526). Language processor 230 then
queries data source 132 for the dynamic data (step 528). In response to
the query, data source 230 returns the value for the dynamic data (step
530).
Language processor 230 then formats the dynamic data and places it into the
appropriate field on the web page (step 534). The processed HTML data with
the embedded dynamic data is then sent via the Internet 170 to the user
that requested it (step 536). Any dynamic data fields on the web page will
have been filled in with the latest values available to web server 220.
The user's web browser 210 will receive the web page, interpret it, and
display it on the user's monitor on user workstation 200. If the end of
the HTML section is encountered (step 540=YES), the web page is done. If
there is more of the HTML section to be processed (step 540=NO), the next
portion of the HTML section is then processed (step 520), until the entire
HTML page is transmitted to the user (step 536 and step 540=YES).
Transaction processor 224 is an application program that can be invoked by
web server application 122 when it receives a request for a web page. The
request is turned over to transaction processor 224. Transaction processor
224 can be created in different forms depending on the particular
computing environment; some examples would be an executable program or a
dynamic link library (DLL). Transaction processor 224 will look for the
requested web page definition in macro file 126. If dynamic data is
required to be put into the web page then a call is made to language
processor 230. Language processor 230 is hard-coded as part of transaction
processor 224.
Language processor 230 forms a query for dynamic data specific to data
source 132. Language processor 230 is thus designed to process queries of
a particular type, which are generally defined by the format (e.g.,
language) of the query. Data source 132 could be an SQL database, or some
other environment where a program can be executed and data returned.
Language processor 230 sends the query to data source 132. The results of
the query (i.e., the dynamic data) are sent back to language processor
230. Language processor 230 extracts the dynamic data it needs, and places
the data in the dynamic data field in the web page that transaction
processor 224 is processing. This process of going out to data source 132
for dynamic data may occur several times for a single building of a web
page, depending on how many dynamic data fields the web page contains. As
the web page is processed, it is sent back across the network to the
user's web browser 210 (step 536) which interprets it and displays it on
the monitor of user workstation 200.
The language processor component 230 of transaction processor 224 is
written (i.e., hard-coded) specifically to service queries for a
particular data source 132 and in a particular data processing language
(i.e., query type). The dynamic data that can be put in web pages is
limited to the data source(s) 132 and the language that the hard-coded
language processor 130 is programmed to understand. The present invention
overcomes this problem of being constrained to a limited number and type
of data sources and languages for dynamic data in web pages.
While web server 220 does provide a mechanism for accessing dynamic data
from a data source and inserting the dynamic data into an HTML page, it
retrieves the dynamic data using a hard-coded language processor 230
within transaction processor 224. This arrangement requires that the
transaction processor 224 be modified if a new data source is identified
as a source of dynamic data. If the new data source contains data in a
different database format, language processor 230 must be modified to
accommodate the new data source and the new format. A much better solution
would allow the addition of new data sources and corresponding language
processors without changing the transaction processor, which is the
preferred embodiment of the present invention, as described below.
Referring now to FIGS. 6 and 7, computer system 100 is configured as a web
server in accordance with a preferred embodiment of the present invention.
Web server 100 includes web server application 122, one or more macro
files 126, a transaction processor 124, a configuration file 128, and
multiple language processors 130 coupled to multiple data sources 132. The
operational features of web server 100 may best be understood with
reference to FIGS. 8 and 9.
The user first sends out a web page request by specifying a URL of the page
(step 510). Assuming the same URL as before, namely
http://www.abcxyz.com/cgi-bin/db2www.exe/wbp1.fil/2ndpage
and assuming that web server 100 has an address of abcxyz.com, web server
100 is contacted (step 512). As shown in the sample URL above, if the web
page request is for a page that contains dynamic data, the URL for the
page will contain a special parameter such as a cgi-bin parameter,
informing web server 100 that another program is needed to process the
URL. When web server 100 sees the cgi-bin parameter in the URL, it calls
transaction processor 124 by passing control to db2www.exe to handle the
request (step 514), passing the macro file name "wbp1.fil" and HTML
section name "2ndpage" as parameters. Note that db2www.exe in this URL
represents the transaction processor 124 programmed in accordance with the
preferred embodiment of the invention, and is therefore not the same
program as Release 1 of DB2WWW described above.
When transaction processor 124 is first initialized, it reads configuration
file 128 (step 810). Referring now to FIG. 9, the configuration
information within configuration file 128 informs transaction processor
124 of the language processors 130 available in the system to process
different types of function calls, and correlates each function identifier
(ID) to a language processor that is programmed to process that particular
type of function. From the URL, web server 100 identifies the appropriate
macro file (wbp1.fil) and finds the HTML section within macro file 126
that contains the desired web page (2ndpage) (step 516), and begins
processing the HTML section (step 520). Transaction processor 124 then
determines if the selected HTML section has a function call for dynamic
data (step 522). If the desired web page has a function call for dynamic
data (step 522=YES), then it uses the function name from the function call
(e.g., function-name in FIG. 9) to find a function definition with the
same name in the function definitions portion of macro file 126.
Transaction processor 124 then obtains the special token or identifier
(ID) from the function definition (step 814). The ID obtained from the
function definition is matched with data previously read from
configuration file 128 to determine which language processor should handle
the function call, and the function call is passed to the appropriate
language processor (step 816). In summary (referring to FIG. 9), when
transaction processor 124 encounters a function (e.g., function-name) that
requires the retrieval of dynamic data, it looks to the function
definition portion of macro file 126 to find a token or identifier (ID)
corresponding to the function-name. Transaction processor 124 then
determines from the data previously read from configuration file 128 which
language processor should process a function with that particular ID.
Referring again to FIG. 8, language processor 130 then generates from the
function call a query to its corresponding data source 132 (step 818), and
the data source returns the requested data to language processor 130 (step
530). The selected language processor will put the dynamic data in a form
transaction processor 124 will understand, and will then pass the data to
transaction processor 124 (step 820). Transaction processor 124 then
places the dynamic data in the appropriate field of the HTML page (step
822). This portion of the HTML page is then sent back to the user (step
536) and is displayed to the user on the monitor attached to user
workstation 200.
Note that detecting the presence of dynamic data in a web page by detecting
certain types of function calls is only one of many ways to determine
whether the selected page includes dynamic data. The correlation between a
function call and dynamic data is used herein for the sake of clearly
explaining the operation of the preferred embodiment, and should not be
construed as limiting. Any form of indicia indicating that dynamic data is
required in the page falls within the scope of the present invention.
With the configuration of the preferred embodiment, language processors 130
are now separate from transaction processor 124. In the preferred
embodiment, each language processor 130 is written to communicate with a
specific data source 132, recognizing that in alternative embodiments two
or more language processor may access a single data source or that one
language processor may access multiple data sources. Language processor
130 can exist as a DLL or some type of shared library, with the exact
implementation depending on the operating system and the web server
interface. Note that data sources 132 can exist within web server 100 (as
shown for Data Source #1 in FIG. 6), or they can be located across a
network on another computer (as shown for Data Sources #2 and #3).
With the mechan | | |
