| SAS/GRAPH Software: Reference |
If you use the HTML or WEBFRAME driver to generate a
drill-down graph, you have no control over the page design. The HTML driver
always displays graphs on a single Web page and requires you to scroll the
page if multiple graphs are produced by the last graphics procedure that is
run. The WEBFRAME driver always displays thumbnail graphs in a left frame
and uses the right frame to display the output that corresponds to a thumbnail
that is selected in the left frame.
If you use ODS to generate a drill-down graph, you can
use style sheets to control some of the page attributes, but you are limited
to the layouts that ODS offers. Although you can use a frame to display a
Table of Contents or Table of Pages, you must display the drill-down graph
on a body page, and when you drill down to target output, the target output
will display in the body page, replacing the drill-down graph.
If you have a good working knowledge of HTML, and you
understand how to generate drill-down graphs in SAS/GRAPH, you can customize
the layout of Web pages that implement the drill-down graphs. For example, Customized Web Page with Drill-down Graph shows
a Web page that cannot be produced with the HTML or WEBFRAME drivers or with
ODS, but that you can customize with help from SAS/GRAPH. On this Web page,
the left frame displays a drill-down bar chart showing a company's regional
sales. When one of the bars in the chart is selected, the right frame displays
a pie chart showing the total sales for the states in the corresponding region.
Customized Web Page with Drill-down Graph
![[IMAGE]](./images/01215133.gif)
For a
customized Web page, SAS/GRAPH produces the GIF
files and an image map for you. You provide the linking information needed
to point to the target output, and you create the HTML files and write the
HTML tags needed to display the output and use the image map.
Thus, customizing the Web page differs in the following
ways from using another method to generate drill-down graphs:
For SAS/GRAPH to generate an image map, the graphics
procedure that produces the graph must use the IMAGEMAP= option and also the
HTML= or HTML_LEGEND= option. IMAGEMAP= causes the procedure to generate an Imagemap data set that contains the following information:
After the procedure generates the Imagemap data set,
you specify that data set as an argument on a call to the IMAGEMAP macro (delivered
with SAS/GRAPH). The macro writes the HTML tags needed to define an image
map for the graph. You then create the HTML files needed to use that image
map and implement the drill-down graph.
An image map must be defined and used in the same HTML
file that references the drill-down graph. To create the HTML files, you can
use a text editor or an HTML editor. Or, you can use DATA step processing
in your SAS program. You can even use a SAS/GRAPH Web driver to generate the
initial files, and then edit those files as needed to customize the page.
For example, you could use the WEBFRAME driver to generate HTML and GIF files,
and then edit the resulting HTML files as needed to customize the page layout
and use an image map. This saves you the trouble of writing all your HTML
files from scratch.
The technique to use for creating the HTML files is
entirely up to you and depends on your needs. For example, if you are generating
your graphs in batch runs and do not want to update the HTML files manually
every time the image map changes, you may want to generate the HTML files
in your SAS program, as shown in Example 5: Customizing a Web Page with a Drill-Down Graph.
The Imagemap data set is created automatically by a
SAS/GRAPH procedure when you specify the IMAGEMAP= option in the procedure's
PROC statement. The following graphics procedures have the IMAGEMAP= option:
You do not have to know how to use the Imagemap data
set directly. You simply specify it as an argument on the IMAGEMAP macro,
which uses the data set to generate an image map for you. The Imagemap data
set contains the following variables:
The IMAGEMAP macro is delivered with SAS/GRAPH. It reads
an Imagemap data set that is generated by a graphics procedure and writes
the HTML tags needed to create an image map that defines hot zones and links
for the graph produced by that procedure. The macro has the following syntax:
%IMAGEMAP(imagemap-data-set, outfile)
The IMAGEMAP macro is delivered as one of the Annotate
macros that come with SAS/GRAPH. To use an Annotate macro, you must provide
your program with access to the data set that contains the macros, and you
must compile the macros. Some sites automatically define a fileref for the
data set that contains the Annotate macros.
If the fileref is set automatically at your site, you
can compile the Annotate macros and make them available by simply submitting
the ANNOMAC macro:
%annomac;
If the fileref is not set automatically, find out from
your SAS Software Consultant where the Annotate macros are stored, and allocate
a fileref that points to the data set:
filename fileref 'external-file';
Then include the Annotate macros in your session:
%include fileref (annomac);
To call the IMAGEMAP macro, you must specify both the
name of the Imagemap data set to be used as input and the name of the output
file where you want the image map defined. The following code assumes that
a graphics procedure has already specified IMAGEMAP=MAPDATA to create the
Imagemap data set named MAPDATA:
/* compile the annomac macros */
%annomac;
/* allocate a file for custom html file */
filename vbar 'external-file';
/* generate image map for drill-down */
%imagemap(mapdata, vbar);
Here, the macro reads the information in the data set
MAPDATA and uses it to write the image map to the file that is referenced
by the fileref VBAR. If the file does not exist, it is created. If the file
does exist, the HTML tags are appended to the end of the file. The resulting
HTML tags resemble the following:
<MAP NAME="BARCHART">
<AREA SHAPE=RECT COORDS="424, 143, 470, 256"
href="reports.htm#central">
<AREA SHAPE=RECT COORDS="366, 175, 412, 256"
href="reports.htm#south">
<AREA SHAPE=RECT COORDS="308, 106, 354, 256"
href="reports.htm#west">
</MAP>
<P>
<IMG SRC="barchart.gif" USEMAP="#BARCHART">
The image map is assigned the same name as the GRSEG
that is produced on the procedure. For example, if the GRSEG is named BARCHART,
then the image-map name will be BARCHART.
The image-map name is written in all uppercase letters.
Because the Web browsers in some operating environments use case-senstive
image-map names, the USEMAP attribute on the <IMG> tag that uses the map
should reference the map's anchor name in all uppercase letters, as shown
in the HTML tags above.
For a customized Web page, you must create all the HTML
files you need to display your output. You can create the files any way you
like. This section shows you how to create an HTML file in a SAS program,
using PUT statements in a DATA step.
To implement a drill-down graph, you need an HTML file
that references the graph. That same HTML file must also contain the image
map that defines the graph's hot zones and the location of the graph's link
targets. When you call the IMAGEMAP macro to create the image map, you can
direct its output to the HTML file that references the graph. To use the IMAGEMAP
macro, you must first compile the Annotate macros that are delivered with
SAS/GRAPH (see About the IMAGEMAP Macro).
The following code creates a file that is referenced
by the fileref VBAR. The code assumes the following:
/* specification for the html file */
filename vbar 'external-file';
/* generate html file to display */
/* drill-down graph */
data _null_;
file vbar;
put '<HTML>';
put '<BODY>';
put '<BASE TARGET=view_pies>';
put '<IMG SRC="barchart.gif" '@;
put ' USEMAP="#BARCHART">';
put '</BODY>';
put '</HTML>';
/* writes image map to file */
%imagemap(mapdata, vbar);
Here, the _NULL_ keyword is used in the DATA step to
suppress the creation of a SAS data set. Instead, output is directed to file
VBAR.
The PUT statements write the HTML tags to create a body
page and to reference the chart that is stored in the file barchart.gif. The
USEMAP attribute on the <IMG> tag indicates that an image map named BARCHART
defines hot zones and links for the chart. The image map does not yet exist,
but it will be appended to the file by the IMAGEMAP macro, which is called
on the last line in the code that is shown above. The <BASE> tag indicates
that the target output for the links will be displayed in a frame named view_pies.
After all the HTML tags have been completed for file
VBAR, the code calls the IMAGEMAP macro, which specifies file VBAR as the
output file. Thus, the macro appends to the end of file VBAR the HTML tags
needed to define the image map. The image map is assigned the name BARCHART
because the GCHART procedure that created file barchart.gif used NAME=BARCHART
to name the resulting graph.
To place the image map in the middle of the file, say
above the <IMG> tag that uses it, you would have to start a new DATA step
after the macro call to continue writing HTML tags to the file. The new DATA
step would have to open the HTML file in "modify" mode, using
an operating-environment specific option on the FILE statement. For example,
some environments use the option MOD. For more information on DATA step programming,
see the SAS Language Reference.
For a complete example that shows how to create all
the HTML files needed to implement a custom Web page, see Example 5: Customizing a Web Page with a Drill-Down Graph.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
