Note: Descriptions are shown in the official language in which they were submitted.
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Methods, Techniques, Software And Systems for Rendering
Multiple Sources of Input into a Single Output
Field of the Invention
The invention relates to methods, techniques,
software and systems for rendering multiple sources of input
into a single output.
Background of the Invention
Software developers currently have a number of tools
for designing documents and pieces of data to be returned in
response to client requests. These tools include various mark
up languages such as HTML~ and XML~, for example. These
mark-up languages allow a software developer to program
using tags. These mark-up languages may contain many
different types of tags, requiring different syntax and/or
different parameters and the different tags may have
different attributes. Applications such as Cold FusionTM,
JSP~ (Java Server Pages) and ASPS (Active Server Pages)
involve programming in tags, known as "tag-based
scripting". These mark-up languages and applications
2o require a developer to learn a complete, often complex,
tag-related syntax to design a document to be returned in
response to a client request. Moreover, developers are
limited by the functionality of the tags.
It would be desirable to reduce the complexity of a
system to design and render documents and improve the ability
of a system to adapt if changes are made in the future, which
would reduce the effort for development, maintenance and future
enhancements of the system.
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Summary of the Invention
According to one aspect, the invention relates to
information presentation in a computer system, and deals more
particularly with a technique, system, and computer program for
applying a polymorphic, inheritance-based approach to render
multiple sources of input data into a single output data
source. This embodiment provides a methodology for the
separation of presentation logic from business logic and data
sources.
According to another aspect, the invention provides a
computer-readable medium storing computer executable
instructions that when loaded in a computer adapts the computer
to render a document from: a template which defines a structure
for the document, the template comprising zero or more region
definitions, each region definition having a region name; zero
or more data providers, each data provider comprising one or
more regions, each region being associated with a region name,
and each data provider being one of either a software data
provider and a non-software provider wherein a software data
provider provides data resulting from execution of software
code and a non-software provider does not provide data
resulting from execution of software code; and wherein each
region can comprise zero or more further regions and each
region can further comprise zero or more further region
definitions; by for each region definition in the template: (a)
identifying which data providers, if any, are associated with
the region name of the region definition; (b) if no data
providers are identified in step (a), then returning a default
value; otherwise (c) of the data providers identified in step
(a), choosing the data providers to be used to provide data in
place of the region definition; and (d) generating data from
the data providers chosen in step (c) and replacing the region
definition in the template with the generated data.
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According to yet another aspect, the invention
provides a computer-implemented method for creating a document
comprising: creating a template defining a structure for the
document, the template comprising zero or more region
definitions, each region definition having a region name;
creating zero or more data providers wherein each data provider
comprises one or more regions, each region being associated
with a region name; and each data provider is one of either a
software data provider and a non-software provider wherein a
software data provider provides data resulting from execution
of software code and a non-software provider does not provide
data resulting from execution of software code; and each region
can further comprise zero or more further regions and each
region can further comprise zero or more further region
definitions; rendering the template, wherein for each region
definition in the template, (a) identifying which data
providers, if any, are associated with the region name of the
region definition; (b) if no data providers are identified in
step (a), then returning a default value; otherwise (c) of the
data providers identified in step (a), choosing the data
providers to be used to provide data in place of the region
definition; and (d) generating data from the data providers
chosen in step (c) and replacing the region definition in the
template with the generated data.
According to yet another aspect, the invention
provides a computer system for creating a document, the system
comprising input hardware and software for a user to create a
template defining a structure of the document, the template
comprising zero or more region definitions, each region
definition having a region name; and for a user to create zero
or more data providers wherein each data provider is associated
with one or more region names; a rendering engine and a
rendering strategy wherein the combination of the rendering
engine and the rendering strategy creates a rendered document
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by (a) identifying which data providers, if any, are associated
with the region name of the region definition; (b) if no data
providers are identified in step (a), then returning a default
value; otherwise (c) of the data providers identified in step
(a), choosing the data providers to be used to provide data in
place of the region definition; and (d) generating data from
the data providers chosen in step (c) and replacing the region
definition in the template with the generated data.
Advantageously, different embodiments of the present
l0 invention may permit:
providing a relatively simple technique for rendering
input data sources into a single output data source;
providing a rendering technique allowing efficient use of
multiple and disparate data sources, such as, for
example: plain text documents, HTML documents, XML
documents, Software objects, etc;
providing a rendering technique that enables different
data retrieval or formatting implementations to be
quickly and easily substituted into the computing
environment, to quickly adapt to changes in data or
formatting requirements, which changes may not
currently be foreseeable;
providing a technique that enables new sources of data to
be quickly and easily added into a rendering
technique, providing greater flexibility in the
manner in which the data sources can be rendered,
where for example, the new sources or data may
override older sources of data, depending upon a
rendering strategy;
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providing a method for separating presentation logic from
business logic and data sources; in other words, a
template for a document, for example, may remain the
same, even though the logic used to produce data for
the template or the data content itself may change;
allowing the separation of dynamic content (eg:
information generated through a software method) from
static content (eg: a text document) which provides a
useful separation of disciplines; such separation of
disciplines has several advantages including the
ability to distinguish between types of data
providers whereby certain types of data providers may
be best created or modified by software programmers
whereas another type of data provider could be
created by anyone, including data entry personnel,
whose knowledge of programming techniques would be
irrelevant;
providing a polymorphic content replacement algorithm or
strategy for selective replacement of data; in other
words, such a strategy would allow for, among other
things, the ability to change the look and feel of
the document to be returned to a client at run time
as well as changing the logic used to create the
document to be returned;
providing an "inheritance-based" content replacement
algorithm by allowing a hierarchical inclusion of
regions within regions, which creates increased
flexibility and allows for the relatively easy
modification or addition of one region within
another; and
providing a value replacement algorithm for use across
multiple document templates and providers of data for
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the templates, allowing for global use of variables
or placeholders, for example.
Brief Description of the Drawings
Preferred embodiments of the invention will now be
described with reference to the attached drawings in which:
FIG la illustrates multiple network interconnected
devices;
FIG lb is a block diagram of the organization of
computer memory of the devices of FIG la;
FIG 2 is a block diagram depicting software and other
components in accordance with an embodiment of the present
invention;
FIG 3a is a generic example of a sample template in
accordance with an embodiment of the present invention;
FIG 3b is an example of a template in accordance with
an embodiment of the present invention;
FIG 3c is an example of a template outline in
accordance with an embodiment of the present invention;
FIG 4a is an example of a non-software data provider
in accordance with an embodiment of the present invention;
FIG 4b is an example of a software data provider in
accordance with an embodiment of the present invention;
FIG 4c is an example of a properties map in
accordance with an embodiment of the present invention;
FIG 4d is an example of another non-software data
provider;
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FIG 4e is an example of another software data
provider;
FIG 5a is an example of a document generated from the
template of FIG 3b;
FIG 5b is an example of a document generated from the
template of FIG 3b, using the document data providers of FIGS
4d and 4e;
FIG 6 is a flow chart illustrating steps performed by
a rendering engine in accordance with an embodiment of the
l0 present invention;
FIG 7 is a flow chart illustrating steps performed by
a rendering engine pursuant to a last-in-first-out rendering
strategy in accordance with an embodiment of the present
invention.
Detailed Description
FIG. la illustrates, by way of example, digital
computer network 10 including computing devices 11, 12 and 13.
Devices 11, 12 and 13 may, by way of example, be personal
computers; mainframe computers; networking equipment such as
routers, switches, frame relays; telephone switching equipment;
or the like. Network 10 may for example, be a wide area
network, conforming to any of a number of known networking
protocols including TCP/IP, IPX, Appletalk, WCP or the like.
Alternatively, network 10 may be a local area network; a
collection of interconnected smaller computer networks
comprising an intranet or Internet; or a portion of the public
Internet. As will be appreciated and as illustrated, network
10 may be interconnected with other networks such as the public
Internet.
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Computing devices 11, 12 and 13 are all network
management devices that store network management data, among
other things. Management of any of the network devices may be
accomplished by access to one device 11, 12 or 13 by one of the
other devices 11, 12 or 13, or other interconnected devices
(not shown), in communication with network 10.
Each computing device 11, 12, and 13 comprises a
processor interconnected with storage memory and a network
interface. Additionally, each computing device may comprise an
input/output peripheral capable of reading data from a computer
readable storage medium, such as a floppy diskette, CD-ROM,
tape or the like. Each computing device may also comprise
other input and/or output hardware and software.
The organization of memory of computing device 11 is
illustrated in FIG. ib. The organization of memory of
computing devices 12, and 13 is similar, but not illustrated.
As shown, loaded within memory of each computing device is
operational software, including preferably an operating system
15; network interface software 17; and application software 16.
As will be appreciated, the operational software may be loaded
from computer readable storage medium 14.
Operating system 15, may for example be a UNIX
operating system. Network interface software 17 typically
comprises software allowing communication of device 11 with the
remainder of network 10 using a known network protocol.
Network interface software 17 may, for example, be an Internet
protocol suite, and could optionally form part of operating
system 15. Application software 16 typically comprises
software that in combination with operating system 15, provides
other desired functionality of devices 11, 12 and 13.
In a distributed system, certain software and/or
hardware is considered as server-side components and other
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software and/or hardware is considered as client-side
components. The software described below could all be resident
on a single device 11, 12 or 13. Alternatively, portions of
the software described below could be resident on one device
12, for example, and other portions could be resident on one or
more other devices 11 and 13, for example.
FIG 2 is a high level block diagram depicting certain
elements of this embodiment and certain of their inputs and
outputs. Although data generally flows in both directions
between the elements shown in FIG 2 (for a request and a
response), the direction of the arrows generally illustrates
that the output of one component is to be used as an input to
another component.
Referring to FIG 2, a template 22, having regions (or
region definitions) 36, is conceptually centrally located,
receiving inputs from non-software data providers 24 (having
regions 34), software data providers 26 (having regions 35) and
properties maps 28. The template 22, the data providers 24,
26, the regions 34, 35, 36 and the properties maps 28 represent
data stored on one or more of the computing devices 11, 12 and
13. A rendering engine 30, a software component, in
combination with a rendering strategy 32, another software
component, determines how the data providers 24, 26 and the
properties maps 28 are used as inputs to the template 22. The
rendering engine 30 receives a client request 20 and ultimately
returns a generated document 38 from the template 22.
As suggested above, all of the components 20-36 could
be resident on a single device 11, 12 or 13. Alternatively,
for example, the client request 20 could originate from one
device 12 and the other components 22-36 could be resident on a
single device 11 or could be resident on two or more devices
11, 13.
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A client request 20 for a document or a piece of data
is received by the rendering engine 30, which rendering engine
30 is typically implemented as software. Hereinafter, the term
"document" may sometimes be used to refer to either a document
or a piece of data. The request 20 is passed to the template
22. As described in greater detail below, information from the
data providers 24, 26 and the properties map 28 is rendered or
generated into a document 38 according to the structure of the
template 22 by the rendering engine 30 pursuant to a strategy
dictated by the rendering strategy 32. A generated document 38
is then returned to the client. These elements may be more
specifically described as follows.
Template 22
The template 22 provides the general structure of the
resulting document 38. A generic sample template 22 is
depicted in FIG 3a. In conjunction with the rendering engine
30, the template 22 determines where and how the various input
data sources (the non-software providers 24, the software data
providers 26 and the properties maps 28) are to be merged. As
will be discussed below, the template 22 identifies region
definitions 36 in a particular sequence. In FIG 3a, the
general type of information to be inserted in the template 22
is depicted in italics. The portions shown in bold can be
inserted verbatim. The mark-up language XML is used in this
example. However, as noted below, a region can theoretically
be defined using other syntaxes or languages.
A region definition 36 is depicted as:
cregion name=~~name of region">default output</region>
The name of the region is added where shown. The
default output 70 may also be added where shown. The other
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portions of the region definition 36, at least for the purposes
of this example, would be written as shown.
A user or developer may add text or data anywhere in
the template 22, and not just in the places as shown in the
sample template 22 of FIG 3a.
Instead of the term "placeholder" 42 in FIG 3a, the
developer would supply an appropriate variable or placeholder
name, such as "user. name" or "country", for example, which
would be associated with a globally defined variable. In this
example, the symbol "$", when on both sides of a term,
signifies a placeholder 42. Ultimately, the rendering engine
30 replaces the placeholder 42 by its globally defined
definition or associated value (as described below with respect
to the properties map 28).
A specific example of a sample template 22 is
depicted in FIG 3b. The template 22 shown in FIG 3b has region
definitions 36a, 36b and 36c. The sample template 22 depicted
in FIG 3b also provides text 40 that will appear in the
resulting document 38 in addition to a shared value or a
placeholder 42, which in this example, is identified as
"user.name".
Regions or region definitions 34, 35~ 36
In general, a region 34, 35 represents a unit of
content or a type of information that may be provided by a non-
software data provider 24 or a software data provider 26. A
template 22 may include several region definitions 36, each of
which may be associated with zero or more regions 34 or 35. '
Similarly, the data providers 24, 26 may also include region
definitions 34, 35. Each region 34, 35 may provide content.
The term "region definition" will generally be used to indicate
a reference to a region. The term "region" will generally be
used to refer to a unit of content associated with a region
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definition. A region or a unit of content could be provided by
a data provider 24, 26, or could also be provided within the
template 22, such as for example, with respect to the default
content 70 described below. (It is also possible that
depending upon the context, the term °region° could refer to
either a °region definition~~ or a "region" as described
herein.)
Non-software providers 24
A non-software provider 24 provides a mechanism by
which a data source can be described statically, in the form of
a text document, for example. Typically, data provided from a
non-software provider 24 does not result from execution of
software code. Non-software providers 24 may also introduce
new region definitions 34. Inherited or nested regions within a
non-software provider 24 are resolved by the rendering engine
30 in combination with the rendering strategy 32, as described
below.
Software data providers 26
Software data providers 26 provide a mechanism by
which a data stream, for example, can be constructed. A
software data provider 26 generates data or information by
processing computer software code (rather than simply being a
text or data file, such as the non-software providers 24). In
other words, a software data provider 26 provides data
resulting from execution of software code. A software data
provider 26 generates information by processing computer
software using a computer programming language. Software data
providers 26 may also introduce new region definitions 35.
Inherited or nested regions within a software data provider 26
are resolved by the rendering engine 30 in combination with the
rendering strategy 32.
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Properties yaps 28
A properties map 28 provides a global list of values
associated with placeholders 42 which can be used by more than
one template 22 and/or software data providers 26 and/or non-
software data providers 24. In other words, properties maps 28
centralize commonly used and shared values among multiple
templates 22, software data providers 26 and non-software data
providers 24.
Rendering Rngine 30
The rendering engine merges the various data sources
(the non-software providers 24, the software data providers 26,
the properties maps 28) into a single document based on the
structure of the template 22 and the rules dictated by the
rendering strategy 32.
Rendering strategy 32
The rendering strategy may be separate from the
rendering engine 30, as shown in FIG 2, or, according to
another aspect of the invention, may be incorporated within the
rendering engine 30 (not shown).
If the data providers 24, 26 include two or more
regions 34, 35 having the same name, then the rendering
strategy 32 determines which region 34, 35 to use. Depending
upon how the rendering engine 30 incorporates regions 34, 35
into the template 22, the resulting document 38 could differ.
For example, if the data providers 24, 26 include two regions
34, 35 of the same name, then the rendering strategy 32 could
choose to use a data provider 24, 26 that was created or added
first (using a first-in-first-out (FIFO) strategy) or the
rendering strategy could choose to use the data provider 24, 26
that was most recently created or added (using a last-in-first-
out (LIFO) strategy).
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A LIFO strategy, for example, allows a later created
region 34 or 35 to override an earlier created region 34 or 35.
Such a LIFO strategy provides an inheritance-type behavior,
described further below. Polymorphic behavior is realized by
the ability to have regions 34, 35 that provide content
dependant on the context of the request. In other words, the
rendering strategy 32 provides a flexible method for
encapsulating decision logic required by the rendering engine
30 to merge or choose among what could be multiple, possibly
overlapping, data sources.
Operational Description
As noted above, FIG 3b shows a sample template 22.
This sample template 22 has three region definitions 36a, 36b
and 36c, namely "DocumentTitle", "DateModified" and
"DocumentContents", respectively. The sample template 22 of
FIG 3b also refers to "user.name", which is a placeholder 42.
Typically, before the template 22 is rendered, the regions 34,
35 associated with the region definitions 36a, 36b and 36c in
addition to the placeholder 42 will have been previously
defined or programmed within the data providers 24, 26 and
properties maps 28 as described below (otherwise, a default
output 70 or an error message will be produced).
FIG 4a shows a sample non-software data provider 24.
The sample non-software provider 24 defines two regions. The
content of the region named "DocumentTitle" is the following
text: "RKO 281: Deconstructing Citizen Kane". The content of
the region named "DocumentContents" provides text to be
included as the body of a review concerning the movie Citizen
Kane, in this example.
FIG 4b shows a sample software data provider 26. The
sample software provider 26 includes a region named
"DateModified". In this example, the content of this region is
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a piece of Java code. However, the code could be in any
language that can be compiled or interpreted by the user's
system. In this example, the piece of Java code returns the
date on which the above noted region "DocumentContents" 34 of
FIG 4a was last modified.
FIG 4c shows a sample properties map 28. In this
case, the sample properties map 28 defines or associates
"user.name" as "John Smith". The properties map 28 could be a
lookup table or any other method or technique for assigning
values, or definitions or strings to variables or placeholders.
Flow chart
A high level algorithm for rendering a template 22
will be now be described. As background for this example, a
user using the device 12 (FIG la), for example, may be visiting
a web site devoted to movie reviews, and the user may have
selected a review for the movie Citizen Kane. A client request
for the document "RKO 281: Deconstructing Citizen Kane" would
then be sent to the rendering engine 30, resident on the device
11 (FIG 1a), for example. Then, the rendering engine 30 locates
the appropriate template 22, which in this case, is the
template shown in FIG 3b. (Alternatively, the client request
20 could be sent to an appropriate Java template object (not
shown), for example, which in turn would invoke the rendering
engine 30.) The rendering engine 30 then traverses the region
definitions 36a, 36b and 36c contained in the template 22 and
queries the data providers 24, 26 to provide content associated
with the region definitions 36a, 36b, and 36c, as shown in flow
chart of FIG 6, and as further described below.
Referring to FIG 6, at step 50, the rendering engine
30 determines if there are any yet to be rendered region
definitions 36 in the template 22. In this example, the first
region definition "DocumentTitle" 36a will be located at step
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52. In cases where there is more than one data provider 24, 26
having the region name being searched for, a rendering
strategy, as shown at step 54, is required to determine which
data providers 24,26 to use. In this example, there is only a
single region 36 named "DocumentTitle" within the data
providers 24, 26 which is that shown in FIG 4a, and which will
be located at step 56. At step 58, the contents of the region
named "DocumentTitle" will be added to the document 38 being
generated in place of the region definition "<region
name="DocumentTitle">Document Title</region>".
Because it is possible for one region 34 or 35 to
include another region 34 or 35 (or another region definition
34 or 35), step 60 determines if one region (or region
definition) 34 or 35 is nested within another region 34 or 35.
In this case, because no region is nested within the
"DocumentTitle" region, the flow chart returns to step 50 to
determine if there are more region definitions 36 in the
template 22.
In this example, because there is an additional
region definition "DateModified" 36b in the template 22, the
rendering engine 30 proceeds to step 52 to obtain the
associated content. At steps 54 and 56, the software data
provider 26 (as shown in FIG 4b) is located. At step 58, the
Java code shown in FIG 4b is executed and the result replaces
the reference to the "DateModified" region definition 36b in
the template 22. At step 60, because the Date Modified region
of FIG 4b does not contain a nested region definition 35, the
flow chart returns to step 50.
At steps 50 and 52, the rendering engine determines
that the next region definition 36 is "DocumentContents" 36c.
At steps 54, 56 and 58 the rendering engine 30 replaces the
reference to the "DocumentsContent" region definition 36c in
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the template 22 with the content of the "DocumentContents"
region shown in FIG 4a.
The rendering engine 30 now returns to step 50.
Because there are no more region definitions 36 in the template
22, the rendering engine proceeds to step 63. At step 63, the
rendering engine 30 looks for placeholders or values 42 in the
template 22 or in any added regions 34, 35 which are defined by
the properties maps 28. At step 63, the rendering engine 30
replaces the placeholders 42 with the associated values or
strings from the properties maps 28. In the example template
22 shown in FIG 3b, the placeholder 42 is named "user.name" and
is delimited by the "$" symbol. The rendering engine 30
replaces "$user.name$" with the value or definition shown in
the properties map 28 of FIG 4c, namely "John Smith". In this
example, the placeholders 42 are replaced at the end of the
rendering process. However, the rendering engine 30 could
replace the placeholders 42 with their associated values or
definitions from the properties maps 28 at any time during the
rendering process.
If a placeholder 42 does not appear in a properties
map 28, then a default value may be used. For example, as one
possibility, if a placeholder 42 does not appear in a
properties map 28, the placeholder 42 may remain unresolved.
Therefore, if in the above-noted example, there were no
properties map 28, the final document 38 of FIG 5a would show
"$user.name$" instead of "John Smith".
At step 64, the rendering engine 30 returns the
generated document 38, which in this example, will look like
document 38 shown in FIG 5a.
It is possible that a region definition 36 may be
included in the template 22 even though there is no associated
region 34 or 35 in a non-software provider 24 or in a software
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data provider 26. In that case, the rendering engine 30 should
have a strategy for proceeding. One strategy is suggested in
the flow chart of FIG 6 at step 66, where the rendering engine
30 loads the region definition's default content, if any.
For example, referring to FIG 3b, if the
"DocumentTitle" region 36a had no corresponding region defined
by the non-software providers 24 or the software data providers
26, then the rendering engine 30 would, in this example, simply
use the default content 70 from the region definition 36a of
the template 22. In this example, as shown in FIG 3b, the
default content 70 is "DocumentTitle", which is the text
between "</region>" and the preceding ">" symbol. Therefore,
in this example, the resulting document 38 (not shown) instead
of that shown in FIG 5a would include the text "DocumentTitle"
in place of "RKO 281: Deconstructing Citizen Kane". (Another
default option is simply to produce an error or default message
such as "no associated region defined".)
LIFO strategy
As noted above, different rendering strategies 32 are
possible. In cases where it is desirable to have more recently
defined regions 34, 35 override earlier defined regions, a LIFO
strategy may be preferred. To illustrate the LIFO strategy,
the template 22 shown in FIG 3b will be considered in
conjunction with the data providers 24, 26, and properties maps
28 shown in FIGS 4a-4c. As well, for this example, additional
data providers 24, 26 as shown in FIGs 4d and 4e will be
considered. For the purpose of this example, the data
providers 24, 26 shown in FIGs 4d and 4e will be considered to
have been added more recently than the data provider 24 shown
in FIG 4a.
The example template 22 shown in FIG 3b will now be
rendered pursuant to the flow chart in FIG 6. The first two
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region definitions "DocumentTitle" 36a and "DateModified" 36b
are rendered in a manner identical to that described above.
However, the "DocumentContents" region definition 36c is
rendered differently because of the recent addition the non-
software data provider 24 shown in FIG 4d. Because there are
now two regions within the data providers 24, 26 associated
with the name "DocumentContents", one shown in FIG 4a and one
shown in FIG 4d, a rendering strategy 32 is implemented to
determine which one will be used. A sample rendering strategy
32 is shown in flow chart of FIG 7.
Two distinct strategies have been implemented in the
chart shown in FIG 7. First, if there are two data providers
having regions of the same name, the rendering strategy 32 will
select a software data provider 26 in preference to a non-
software provider 24. If there are two or more software data
providers 26 having regions of the same name, the rendering
strategy 32 will use the most recently added software provider
26. If there are two or more non-software providers 24 having
regions of the same name (and no software providers having a
region of the same name), the rendering strategy 32 will use
the most recently added non-software provider 26, pursuant to
the LIFO strategy.
Accordingly, at step 54 of FIG 6, the rendering
engine 30 will follow the flow chart of FIG 7 to implement the
above-described example of a rendering strategy. At step 70 of
FIG 7, the rendering strategy 32 searches the software data
providers 26 for a region named "DocumentContents", starting
with the last added software data provider 26. At step 74, the
rendering engine 30 determines that there are no software data
providers 26 having a region named "DocumentContents".
Accordingly, the rendering engine considers the non-software
data providers 24 at step 76. At step 78, the rendering engine
30 locates the most recently added non-software data provider
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24 shown in FIG 4d and at step 80 of FIG 7 returns this
provider 24 to step 56 of the flow chart of FIG 6.
At step 60 of FIG 6, the rendering engine 30
determines that the region definition "DocumentSummary" is
nested within the "DocumentContents" region. Accordingly, the
rendering engine 30 returns to step 54 to render the
"DocumentSummary" region definition. The rendering engine 30
follows the steps shown in the flow chart of FIG 7 to render
the "DocumentSummary" region. At step 74, the rendering engine
30 finds no software data provider 26 having a
"DocumentSummary" region. Accordingly, at step 76 of FIG 7,
the rendering engine 30 searches the other non-software data
providers 24 for a "DocumentSummary" region. At step 78, the
rendering engine 30 finds no "DocumentSummary" region.
Accordingly, at step 66 of FIG 6, because no provider was
located at step 56, the rendering engine 30 loads the default
content 70 from the "DocumentSummary" region definition of FIG
4d. In other words, the rendering engine 30 loads "This
document also deconstructs Well's Citizen Kane..."
The rendering engine 30 then proceeds to step 60 to
determine that there is another nested region definition
(namely the "DocumentLength" region definition) located within
the "DocumentContents" region. The "DocumentLength" region is
provided in the software data provider 26 shown in FIG 4e. In
this example, the software provider 26 shown in FIG 4e is a
piece of Java code. The rendering engine 30 will have the Java
code executed and will then return a value representing the
document length, which value will be inserted in place of the
Document Length region definition of FIG 4d.
The resulting rendered document 38 is shown in FIG
5b.
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By way of further example, if the data provider shown
in FIG 4d were considered to be a software data provider 26
instead of a non-software data provider 24, the resulting
document 38 as shown in FIG 5b would be the same. To
illustrate, the rendering strategy 32 would proceed through
steps 70-74 of FIG 7 and determine that there is a software
data provider 26 having a region named "DocumentContents",
namely that shown in FIG 4d. Accordingly, the rendering
strategy 32 proceeds to step 80 where it returns the most
recently added software provider 26 having the name
°DocumentContents° shown in FIG 4d. The rendering strategy 32
would then return to step 54 of FIG 6 and proceed as noted
above. The resulting document 38, as indicated above, and as
shown in FIG 5b, would be the same, as when FIG 4d is properly
considered as a non-software data provider 24.
The above example considered a LIFO rendering
strategy 32 where the software data providers 26 were used in
preference to the non-software providers 24. Therefore, if
regions having a particular name were defined in both a
software data provider 26 and a non-software provider 24, the
software data provider 26 would be used instead of the non-
software provider 24.
However, the rendering strategy 32 could be modified
in any number of different ways. For example, the rendering
strategy could:
-consider the non-software providers 24 before the
software data providers 26;
-use a first-in-first-out (FIFO) strategy instead of a
LIFO strategy;
-use a developer-defined priority strategy where the
developer, during the creation of the data providers,
assigns a priority value to each data provider (not
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shown). In this scenario, during rendering, if there
are two or more data providers having the same region
name, the data provider having the highest priority
is used.
Creating templates 22, data providers 24, 26,
properties maps 28, etc. and then linking them
Construct a template outline
FIG 3c illustrates a high level sample template
outline 90 of a template 22 that could be created prior to
creating a template 22. The template outline 90 could be
created in any word processing program, for example, by a
software developer or anyone else, who may or may not be
familiar with any programming languages. Although the creation
of a template outline 90 is not necessary for the ultimate
creation of a template 22, the outline 90 may be useful. Among
other advantages, the outline 90 allows a person designing the
template 22 to provide an outline at a high level, relatively
quickly, because details can be omitted and because adherence
to rules of a programming language need not be considered.
Accordingly, it is not necessary for the person creating the
template outline 90 to be competent in a programming language.
The template outline 90 of FIG 3c shows the basic
region names and placeholders that will make up the ultimate
template 22. In other words, the locations of the region
definitions 36a, 36b and 36c relating to title, date and
document contents have been specified in addition to the
location of the placeholder 42 for the user's name.
Transform template outline 90 to template 22
In this example, the template outline 90 of FIG 3c is
transformed to the template 22 as shown in FIG 3b. There are
two basic methods for producing the transformation. The first
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method is simply to have a developer replace the references to
region definitions and placeholders with the proper syntax and
content as shown in FIG 3b. In that case for example, the
developer would replace "DocumentTitle" in FIG 3c with the
first line as shown in FIG 3b. (The language shown for the
template 22 of FIG 3b is XML. However, any syntax or language
could theoretically be used.) This method may be referred to
as a manual transformation.
The second method involves an automatic or semi-
automatic transformation from the template outline 90 to the
template 22. In this method, a parser (not shown) is used
which recognizes certain key words and translates those key
words into the proper syntax for region definitions and
placeholders adding content as required. Therefore, for
example, the parser would recognize the character string
"Document Title" and replace it automatically with the region
definition 36a shown on the first line of FIG 3b. Similarly,
the parser would recognize "some name" and replace it
automatically with the placeholder "$user.name$".
It should be noted that with respect to the template
22 shown in FIG 3b, all of the region definitions 36a, 36b, 36c
share the same mark-up schema; there is no differentiation
between which region definitions relate to non-software
providers 24 as opposed to software data providers 26. (It
should also be noted that the data providers 24, 26 may use the
identical mark-up schema or a different mark-up schema as the
region definitions 36 in the template 22 and the region
definitions 34, 35.) Accordingly, the person who creates the
template 22 need only know a single syntax rule.
Construct non-software providers 24
The non-software providers 24, similar to the
software data providers 26, can theoretically be created at any
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time prior to rendering, using input and/or output hardware and
software known to those skilled in the art. The non-software
providers 24 will likely usually be created by a word
processing program or text editor and may appear in a form
similar to that shown in FIG 4a.
Construct software data providers 26
As noted above, in the usual case, the software data
providers 26 can theoretically be created at any time prior to
rendering (although the result produced by the software data
l0 provider 26 may only be known at run time, depending upon the
particular case). FIG 4b illustrates a sample software data
provider 26. In this example, the software data provider 26 is
a piece of Java code which returns a date. However, a software
data provider 26 could theoretically use any language that can
be interpreted or compiled by the local environment.
Construct properties maps 28
The properties maps 28 could be created at any time
prior to rendering. A sample properties map 28 is shown in FIG
4c. The properties maps 28 link placeholders to their assigned
values. The properties maps 28 could be implemented by
numerous different techniques known to those skilled in the
art, including look-up tables.
Link providers 24, 26 and properties maps 28 to the template 22
The template 22 is linked to the non-software
providers 24, the software data providers 26 and the properties
maps 28. This linking may be accomplished prior to the
rendering process.
Invoke the rendering process
24
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This process was described above with respect to FIGS
6 and 7.
Numerous modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that within the scope of the
appended claims, the invention may be practised otherwise than
as specifically described herein.
