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SAS/IntrNet 8.2: Application Dispatcher |
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The Output Delivery System (ODS) enables SAS procedures to generate output in several different formats. One of these output formats is HTML. You can use ODS in your Application Dispatcher programs to easily create Web pages containing HTML and graphics. This page discusses features and options of ODS that are appropriate for the Application Dispatcher environment. ODS can be used in other SAS environments and can generate other forms of output. For more information about ODS, refer to the Guide to the SAS Output Delivery System.
HTML output is enabled with the ODS HTML statement. The ODS HTML statement can create
ODS may also generate additional HTML or image files if you split the output across multiple body pages or you use embedded GIF or JPEG images to display graphics.
The HTTP protocol used by the Application Dispatcher can deliver only one output file back to the browser per request. This output file is written to the _WEBOUT fileref. Because ODS generates multiple output files in many cases, the extra files must be stored in a temporary location and retrieved by the browser in subsequent requests. The Application Server automatically creates a unique temporary catalog for every request for this purpose. The two-level catalog name is defined in the special macro variable _TMPCAT. ODS must also put hyperlinks and inline image links into the HTML that it generates that will retrieve the files from the temporary catalog. The special macro variable _REPLAY contains the base URL used to create these links.
To enable the above features, any Application Dispatcher program that uses ODS to generate HTML should include the following options on the ODS HTML statement:
ods html path=&_tmpcat (url=&_replay) rs=none ...;
Note: The RS=none option forces ODS to perform record based output and is required when writing to the _WEBOUT fileref or to a catalog entry.
ODS is capable of creating a number of different layouts for your output. All layouts have one thing in common: the "primary" page must be returned directly to your browser (via the _WEBOUT fileref). The page written to the _WEBOUT fileref must be preceded by an HTTP header with the appropriate content-type field.
Starting with Release 8.2, the automatic HTTP header generation feature recognizes some ODS output types and generates appropriate content-type headers. Supported output types include HTML, GIF, and JPEG. An appropriate content type must be manually set with APPSRV_HEADER function for all other output types.
In Release 8.1, ODS output was assumed to be in HTML and a corresponding HTTP content-type header was generated. The APPSRV_HEADER function could be used to override this value. In releases prior to 8.1, you are required to manually write the HTTP header to _WEBOUT or (for HTML output only) you may force ODS to write the header with the (dynamic) option on the ODS HTML statement.
The following annotated examples illustrate how to return various ODS layouts to your browser. For these examples, we will use the following data set:
data stocks;
length symbol $4 price 8.;
input @1 symbol price;
label symbol = 'Symbol'
price = 'Share Price';
format price 7.2;
cards;
AMD 23.50
BORL 9.31
CA 47.25
CPQ 32.06
DELL 139.88
GTW 44.00
HWP 67.00
IBM 104.44
INTC 89.69
MSFT 84.75
ORCL 24.63
SUNW 47.63
;
run;
The examples are
When you return only the body output to your browser, the page will be rendered as a single, unframed page. Sample code to produce such output is shown below.
ods listing close;
ods html body=_webout
path=&_tmpcat (url=&_replay) rs=none;
title 'Stock Prices';
proc print data=stocks label noobs; run; quit;
ods html close;
Because the body file is the only file created, it is the primary file and is directed to the fileref _WEBOUT.
You can return the Table of Contents (or Table of Pages) and the body file using ODS framed output. In this case, the file created by the ODS HTML FRAME option is the primary file, and it must be directed to _WEBOUT. Other files will be stored in the temporary catalog in the WORK library and will be replayed automatically at the proper time.
The sample code below illustrates the creation of a Table of Contents in addition to the body file.
ods listing close;
ods html frame=_webout
body=b.html
contents=c.html
path=&_tmpcat (url=&_replay) rs=none;
title 'Stock Prices';
proc print data=stocks label noobs; run; quit;
proc contents data=stocks; run; quit;
ods html close;
The body and contents files are directed to the temporary catalog and will be named B.HTML and C.HTML, respectively. You can choose any valid SAS name for the entries, but the object type must be HTML. Do not enclose the name in quotes or it will be interpreted to be an external file rather than a catalog entry.
You may want to return only the Table of Contents to your browser to avoid using HTML frames. The page will be rendered as a single, unframed page. Links on the Table of Contents page will allow you to load body output to the browser. A simple modification to the previous example will drop the FRAME keyword and make the contents file the primary file returned to _WEBOUT.
ods listing close;
ods html contents=_webout
body=b.html
path=&_tmpcat (url=&_replay)
rs=none;
title 'Stock Prices';
proc print data=stocks label noobs; run; quit;
proc contents data=stocks; run; quit;
ods html close;
When you click on an item in the Table of Contents, the body file will be replayed from the temporary WORK catalog.
The code below will return framed output consisting of the Table of Contents and the body, which contains integrated graphics and text. Note that no special ODS keywords were required to create and store the graphic images. This example is essentially the same as the Body and Table of Contents example with some SAS/GRAPH code added.
ods listing close;
ods html frame=_webout
body=b.html
contents=c.html
path=&_tmpcat (url=&_replay) rs=none;
goptions reset=all;
goptions device=gif
colors=(red orange yellow ligr green blue)
ctext=black cback=white;
title 'Stock Prices';
axis1 major=none minor=none value=none;
proc gchart data=stocks;
hbar3d symbol / sumvar=price
subgroup=symbol
shape=cylinder
patternid=subgroup
raxis=axis1;
run; quit;
title;
proc print data=stocks label noobs; run; quit;
proc contents data=stocks; run; quit;
ods html close;
HTML and graphics created by ODS in the _TMPCAT catalog must eventually be deleted. The Application Server will handle this task automatically. By default, a temporary catalog will be deleted if it is not used for a period of 15 minutes. This timeout value can be changed with the SESSION TIMEOUT=seconds option on PROC APPSRV, or with the APPSRV_SET('session timeout',seconds) DATA step function. All temporary catalogs are deleted immediately when a server is stopped.
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SAS/IntrNet 8.2: Application Dispatcher |
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