Specifying URLs

Table 4-1: ION Script Tags That Accept URLs as Values

Table 4-1: ION Script Tags That Accept URLs as Values
ION Script Tag	Attribute	Allowable Protocols
<EVENT_DECL>	ACTION	http, https, file, ion
<ION_BODY>	BACKGROUND	http, https, file
<ION_BUTTON TYPE="IMAGE">	SRC	http, https, file
<ION_IMAGE>	SERVER	http, https
<ION_INCLUDE>	SRC	http, https, file, ion

In addition, the following HTML tags have an attribute that can take a URL that points to an ION Script page:

Table 4-2: HTML Tags That Accept URLs as Values

Table 4-2: HTML Tags That Accept URLs as Values
HTML Tag	Attribute	Allowable Protocols
<FORM>	ACTION	http, https, file, ion
<FRAME>	SRC	http, https, file, ion
<IFRAME>	SRC	http, https, file, ion

http - used to specify the location of a file on a remote network such as the WWW.

https - used to specify the location of a file on a remote network handling secure transactions.

file - used to specify a file (except for .ion) that is accessible on a particular host computer.

ion - used to specify the URL of a .ion file, either as an event action or an included file. Files specified using the ion:// protocol are parsed by the ION Script parser. URLs using the ion:// protocol cannot be used in HTML tags, nor can they be entered in the browser's location field.

Note
Because UNIX is case-sensitive, make sure if using a UNIX Web server that URLs used in your ION Script and HTML pages use the same case as the files to which they refer.

HTTP URLs

HTTP (Hypertext Transfer Protocol) is the protocol used to transfer HTML files over a network. Cases in which you would use the http:// protocol in your ION Script applications include:

when specifying an HTML page as the EVENT attribute to the ION_BUTTON or ION_IMAGE tag

when including an HTML page using the ION_INCLUDE tag

when adding a link to another HTML page from your ION Script page, using the HTML <A> tag or the ION_LINK tag

HTTPS URLs

HTTPS (Hypertext Transfer Protocol, Secure) is the protocol used to transfer files over a network using secure transactions. The https:// protocol behaves like the http:// protocol, but is intended to provide secure communication of information such as credit-card numbers.

You need only specify this protocol to take advantage of this security, which the Web server and browser handle for you. If you want to use https://, you can change existing references to http:// in the following three places:

The Image Server URL configuration setting (used to find ion-i)

The ION Script Parser URL configuration setting (used to find the parser via a URL) — the ion:// protocol uses this setting

The .ion and .html code used with ION

File URLs

File URLs are used to access files on a particular host computer, as opposed to files located on a remote network such as the WWW. The file:// protocol is intended to provide access to text and other files on your Web server, such as when you want to include a file in your ION Script page using the ION_INCLUDE tag.

If the path is absolute, the leading / must be present, as in the following examples:

ION URLs

The ion:// protocol causes the page referred to in the URL to be parsed by the ION Script parser. When the ion:// protocol is used, the page referred to in the URL will be parsed as an ION Script file no matter what extension the file uses. For example, the following EVENT definition causes the file myfile.xxx to be parsed as an ION Script file:

The only times you specify the ion:// protocol are when you define an EVENT attribute as another ION Script page, and when you include an ION Script file using the SRC attribute of ION_INCLUDE. Note that you cannot use the ion:// protocol in the following ways:

For the SRC attribute of ION_BUTTON, which must point to an existing image file

In HTML tags

In the location field of the browser

Absolute Paths vs. the ION Search Path

How you specify file:// and ion:// URLs determines whether an absolute path or the ION Search Path is used to locate the file. The ION Search Path is a search path specified in the configuration utility or .ionsrc file (see ION Search Path).

If only a filename is entered, the ION Search Path is used for the path and the leading / may be omitted, For example, if the following URL is used, ION Script will search for include.ion in the ION Search Path:

If only a filename is entered, but you do include the leading /, the absolute search fails and the ION Search Path is used. For example:

If the entire path is used, and you do not include the leading /, as in the following example, the URL is NOT valid:

ion://f:/projects/ionscript/include.ion

IDL Online Help (March 06, 2007)