$Web_URL_Encode and $Web_URL_Encode_Lstr

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Revision as of 01:17, 16 April 2013 by Admin (talk | contribs) (→‎Syntax)
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Do web URL encoding

$Web_URL_Encode and $Web_URL_Encode_Lstr encode special characters into the URL "% hex hex" format, which has particular use constructing isindex strings for anchor tags or redirection.

Syntax

%OUT = $Web_URL_Encode( input_string )

$Web_URL_Encode takes a single string argument and returns that string with special characters encoded using the URL "% hex hex" format.

The only parameter is the input string to be encoded. If this string is omitted, a null string is returned.

Usage notes

  • $Web_URL_Encode_Lstr is identical to $Web_URL_Encode with the exception that it is longstring capable: it can take a longstring input and produce the appropriate longstring output.
  • For $Web_URL_Encode, if the result of the encoding produces a string longer than 255, the result is truncated, at 255 (or less, if necessary, to avoid producing a partial "% hex hex" sequence). For $Web_URL_Encode_Lstr, no truncation should occur.
  • $Web_URL_Encode and $Web_URL_Encode_Lstr are useful for composing the isindex string portion of a URL ("HTTP://host/path?isindex") for redirection, or for composing the HREF= value in the HTML anchor tag ("<A HREF=...").
  • * Use $Web_URL_Encode to create % hex hex like browser does with FORM METHOD=GET printText <form method=get action="{$Web_Hdr_Parm('URL')}"> printText Use this isindex: <input name=a value=""> %INPUTA = $Web_Parm('a') %URLENC = $Web_URL_Encode(%INPUTA) printText <input type=submit value=Submit> printText
    <a href="{$Web_Hdr_Parm('URL')}?input={%URLENC}">Click for same result</a> printText



    printText <xmp> printText PARM a:{%INPUTA} printText URLENC:{%URLENC} printText </xmp>

    If you enter the following into the form:

    10 + 3.14 * R*R*R * 2/3

    The value displayed after URLENC is:

    10+%2B+3.14+*+R*R*R+*+2%2F3

    + is used to stand for a blank, % introduces a hex encoding,2B is the ASCII code for +, and 2F is the ASCII code for a forward slash ( / ). (Note: this is a subtle and tricky example.) Using Netscape 4.5 as the guide, the 4 non-alphanumerics that are not encoded are underscore ( _ ), hyphen ( - ), asterisk ( * ), and period ( . ).