ION Script Configuration Options

The following configuration options are available in ION Script. The options are grouped as they are on the tabs of the Windows configuration program, IONScriptConfig.exe, and in the UNIX resource file .ionsrc.

Images

Width, Height

The Width and Height fields are used to specify the default dimensions, in pixels, of images created with the ION_IMAGE tag. These default values can be overridden by specifying the WIDTH and HEIGHT attributes of the ION_IMAGE tag.

Direct Graphics Image Type

The Direct Graphics Image Type specifies the image format for images created with ION_IMAGE with the TYPE attribute set to DIRECT, which causes the image to be created using IDL's Direct Graphics. This default value can be overridden by specifying the IMG_TYPE attribute of the ION_IMAGE tag. See Graphics in ION Script for a discussion of how to choose the proper image format.

Object Graphics Image Type

The Object Graphics Image Type specifies the image format for images created with ION_IMAGE with the TYPE attribute set to OBJECT, which causes the image to be created using IDL's Object Graphics. This default value can be overridden by specifying the IMG_TYPE attribute of the ION_IMAGE tag. See Graphics in ION Script for a discussion of how to choose the proper image format.

Label

The Label field is used to specify the default text displayed in place of an image for browsers that do not support images, and for browsers in which the automatic display of in-line images has been turned off. This default value can be overridden by specifying the LABEL attribute of the ION_IMAGE tag.

This label is also used in some cases as the tooltip that appears when you hold the mouse cursor over the image, depending on which browser type and version you are using. Because different browsers (and different versions of each) implement alternate text and tooltips differently, it helps to know how ION Script maps the label to HTML. This label value (or the LABEL attribute of ION_IMAGE, if specified) becomes the value of the ALT attribute of the HTML <IMG> tag for an ION_IMAGE without an EVENT, or the ALT attribute of the <INPUT TYPE="IMAGE"> tag for an ION_IMAGE with an EVENT. Because some browsers handle images created with the <IMG> tag differently than those created with the <INPUT> tag, the name of the EVENT may be displayed in place of the value specified for the label if the EVENT attribute of the ION_IMAGE tag has been specified for an image.

Border

The Border field is used to specify the default thickness of the border drawn around an image created with ION_IMAGE or an ION_BUTTON of type IMAGE. A setting of 0 causes images to be drawn without a border. This default value can be overridden by specifying the BORDER attribute of the ION_IMAGE or ION_BUTTON tag.

When the EVENT attribute has been specified for the ION _IMAGE tag, the border is drawn in the color specified by the LINK attribute of the ION_BODY tag, if used, or in the link color used by the browser. If no EVENT has been specified, the border color is black. If desired, you could wrap the ION_IMAGE tag in a <FONT> tag to specify a different color as follows:

<FONT COLOR="#808080">  
<ION_IMAGE> ... </ION_IMAGE>  
</FONT>

URLs

Image Server URL

The Image Server URL field is used to specify the path to the ION Script Image Server, ion-i. This default value can be overridden by specifying the SERVER attribute of the ION_IMAGE tag. See ION_IMAGE.

ION Script Parser URL

The ION Script Parser URL field is used to specify the path to the ION Script parser, ion-p.

Files

IDL Search Path

The IDL Search Path field is used to specify the search path used by IDL for .pro and .sav files. To specify multiple directories, separate each directory with a semicolon (Windows) or a colon (UNIX). Place the "+" symbol at the beginning of a directory to indicate that all subdirectories of the specified directory should be searched. For example, the following Windows IDL Search Path specifies that the directory C:\ITT\IDL63\products\ION63\ion_script\examples and all its subdirectories be searched, as well as the directory C:\ion\pro:

+C:\ITT\IDL63\products\ION63\ion_script\examples;C:\ion\pro

The following UNIX IDL Search Path specifies that /usr/local/itt/ion be searched, as well as the directory /home/ion and all its subdirectories:

/usr/local/itt/ion:+/home/ion

Note
By default, the directory \ITT-DIR\IDL63\products\ION63\ion_script\examples (Windows) or /ITT-DIR//ion64/ion_script/examples (UNIX) and its subdirectories are automatically searched by IDL. You do not need to add this directory to the IDL Search Path.

Note
On UNIX, make sure that any directory you add to the IDL Search Path has the proper read permissions.

See Where to Store Your Files for strategies on locating IDL files.

ION Search Path

The ION Search Path field is used to specify the search path for URLs using the file:// or ion:// protocols. ION Script searches the ION Search Path for the specified file specified by the "page" parameter in the URL. When ION Script searches the ION Search Path, it will search all directories specified in this field in the order listed. Multiple directories can be specified by separating the directory names with a semicolon (Windows) or colon (UNIX), as in the following examples:

Windows: C:\itt\IDL63\products\ION63\ion_script\examples;C:\ion;C:\ion\test

UNIX: /usr/local/itt/ion64/ion_script/examples/:
/home/ion:/home/ion/test

Note
You cannot use the "+" symbol in the ION Search Path to indicate that all subdirectories of the specified directory should be searched. You must explicitly specify each directory to be searched.

If you specify an absolute path in your URL, such as

http://myserver/cgi-bin/ion-p?page=c:\ion\myfile.ion)

ION Script attempts to execute the specified page and does not search the ION Search Path. See Specifying URLs and Absolute Paths vs. the ION Search Path for more on URLs and the ION Search Path. See Where to Store Your Files for strategies on locating your .ion and .html files.

Temp Location

Set this field to the path specifying the location of the temporary graphics and text files that ION Script creates. If not specified, UNIX servers will write to /tmp, and Windows servers will write to the location specified by the TEMP system environment variable. The value of this setting can be accessed programmatically via the $ION.temp system variable.

Note
If the directory you have specified does not exist, or if the web server does not have permissions to write to the directory, images created with the ION_IMAGE tag do not display, and ION Script does not display any errors. Make sure that the temp directory you have specified exists and the web server has permissions to write to the temp directory.

Text Extensions

The Text Extensions field is used to specify the file extensions that are to be considered text files by ION Script. Separate multiple extensions by commas, such as

.txt,.text

You can omit the period:

txt,text

Any extension listed in the Text Extensions field can be used in place of xxx in the following cases, and the files will be parsed as text files:

When included with ION_INCLUDE:

<ION_INCLUDE SRC="filename.xxx"/>

When an EVENT points to a text file as in

<EVENT_DECL NAME="event" ACTION="myfile.xxx"/>

Whenever a URL of the following format is used:

http://server/cgi-bin/ion-p?page=filename.xxx

When an ION Script page is the action of an HTML form:

<FORM NAME="MyForm" ACTION="http://server/cgi-bin/ion-p" >  
   <INPUT TYPE="HIDDEN" NAME="page" VALUE="filename.xxx" >  
</FORM>

See ION_INCLUDE for an example that shows how text files are handled by ION Script. See HTML Forms vs. ION Script Forms for more on making ION Script pages the action of an HTML form.

Note
If the ion:// protocol is used, the file is parsed as an ION Script file no matter what extension the file uses.

ION Extensions

The ION Extensions field is used to specify the file extensions that are to be considered ION Script files by ION Script. Separate multiple extensions by commas, such as

.ion,.xyz

You can omit the period:

ion,xyz

Any extension listed in the ION Extensions field can be used in place of xxx in the following cases, and the files will be parsed as ION Script files:

When included with ION_INCLUDE:

<ION_INCLUDE SRC="protocol://filename.xxx"/>

When an EVENT points to an ION Script file:

<EVENT_DECL NAME="event" ACTION="myfile.xxx"/>

Whenever a URL of the following format is used:

http://server/cgi-bin/ion-p?page=filename.xxx

When an ION Script page is the action of an HTML form:

<FORM NAME="MyForm" ACTION="http://server/cgi-bin/ion-p" >  
   <INPUT TYPE="HIDDEN" NAME="page" VALUE="filename.xxx" >  
</FORM>

See HTML Forms vs. ION Script Forms for more on making ION Script pages the action of an HTML form.

Note
If the ion:// protocol is used, the file is parsed as an ION Script file no matter what extension the file uses.

Redir Protocols

When ION Script encounters a URL that uses a protocol specified in the Redir Protocols field, it will redirect to the URL rather than attempt to load the URL. Redirecting to a Web page is usually quicker than loading the page, and when a URL is outside a firewall, it may not be possible to connect to the site. In this case, a redirect allows you to load the URL. The URLs to which this applies include:

EVENT actions

URLs that use the query string format (?page=url)

URLs specified as the VALUE of a hidden form field with NAME="page" in an HTML form (when the ACTION of the form is the ION Script parser). See HTML Forms vs. ION Script Forms for more on making ION Script pages the action of an HTML form.

Format

Use <PRE> with Text Files

Select this checkbox on Windows, or set "Pre Txt = t" in the .ionsrc file on UNIX, if you want text files parsed by ION Script to be rendered using the HTML <PRE> tag. Text files are parsed by ION Script in the following cases:

When included with <ION_INCLUDE SRC="filename.txt"/> (or other extensions defined in the Text Extensions field)

When an EVENT points to a text file

Whenever a URL of the following format is used:

http://server/cgi-bin/ion-p?page=filename.xxx

where xxx is any extension listed in the Text Extensions field.

The following figure shows the difference between included text files when this feature is turned on and off:

Figure 1-6: File Comparisons

Figure 1-6: File Comparisons

For more on including text files, see ION_INCLUDE.

Default of PRE="TRUE" for <ION_DATA_OUT>

Select this checkbox on Windows, or set "Pre DO = t" in the .ionsrc file on UNIX, to use TRUE as the default value of the PRE attribute of the ION_DATA_OUT tag. See ION_DATA_OUT for a discussion and example using the PRE attribute.

Select this checkbox on Windows, or set "Use Copy = t" in the .ionsrc file on UNIX, to display the © symbol when using the $Document.COPYRIGHT system variable. See COPYRIGHT and $Document for more on including a copyright statement in an ION Script page.

Debug

ION Debug Location

Set this field to a writable path specifying the location on the server machine in which to write the debug log file. The debug log file is created when the DEBUG attribute of either the ION_DATA_OUT or ION_IMAGE tag is set to TRUE. This debugging file contains the exact code sent to IDL, as well as any errors reported by IDL. If not set, the file is written to the default location that your Web server uses for CGI executables. For example, on the Apache Web server, this would be the cgi-bin directory.

ION Debug Filename

Set this field to the filename of the debug log file. The debug log file is created when the DEBUG attribute of either the ION_DATA_OUT or ION_IMAGE tag is set to TRUE. This debugging file contains the exact code sent to IDL, as well as any errors reported by IDL. Instead of using a specific filename, you can include the %d formatting string in it, such as "ioni-log%d.txt". This causes the process ID of ion-i to be inserted where the formatting characters are. Because the process ID is different each time ion-i is requested, the log filename is different each time, thereby preventing the log file from being overwritten. If not set, the default filename is "ion-out%d".

Syntax Logging

This field defines the default method for reporting ION Script syntax errors. On Windows, select one of the following buttons:

Off — Error messages are not reported.

As Comment — Error messages are included in the returned HTML page as part of an HTML comment. This makes the error messages accessible but invisible to the client. To view the error messages, you must view the source of the HTML page sent to the browser by selecting View

Page Source (Netscape) or View

Source (Internet Explorer).

As PRE Text — Error messages are included in the returned HTML page as <PRE> text, and will appear at the bottom of the returned HTML page. This is useful during development of your ION Script applications.

On UNIX, set the "ION Debug Syntax" value to either "OFF," "COMMENT," or "PRE" in the .ionsrc file.

The method selected in the ION Script Configuration Utility or .ionsrc file becomes the default method for error reporting. This default method can be overridden on a page by page basis by setting the SYNTAX attribute for the <ION_SCRIPT> tag to either "OFF," "COMMENT," or "PRE."

IDL Online Help (March 06, 2007)