View source for $Web URL Encode and $Web URL Encode Lstr

{{DISPLAYTITLE:$Web_URL_Encode and $Web_URL_Encode_Lstr}}
<span class="pageSubtitle"> Do web URL encoding</span>

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

==Syntax==
<p class="syntax"><span class="term">%out</span> = <span class="literal">$Web_URL_Encode</span>( <span class="term">input_string</span> )
</p>

<var>$Web_URL_Encode</var> 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==
<ul>
<li><var>$Web_URL_Encode_Lstr</var> is identical to <var>$Web_URL_Encode</var> with the exception that it is longstring capable: it can take a longstring input and produce the appropriate longstring output.

<li>For <var>$Web_URL_Encode</var>, if the result of the encoding produces a string longer than 255, the result is truncated, at 255 (or less, if necessary, to avoid producing a partial "% hex hex" sequence). For <var>$Web_URL_Encode_Lstr</var>, no truncation should occur. 

<li><var>$Web_URL_Encode</var> and <var>$Web_URL_Encode_Lstr</var> are useful for composing the isindex string portion of a URL ("HTTP://host/path?isindex") for redirection, or for composing the <code>HREF=</code> value in the HTML anchor tag ("<A HREF=...").

<li><p class="code">&#42; Use <var>$Web_URL_Encode</var> 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 = $Web_URL_Encode(%INPUTA)
printText <input type=submit value=Submit>
printText &lt;br>&lt;a href="{$Web_Hdr_Parm('URL')}?input={%URLENC}">Click here for same result</a>

printText &lt;br>&lt;hr>&lt;br>
printText &lt;xmp>

printText PARM a:{%INPUTA}
printText URLENC:{%URLENC}
printText &lt;/xmp>
</p>

If you enter the following into the form:
<p class="code">10 + 3.14 * R*R*R * 2/3
</p>

The value displayed after URLENC is:
<p class="code">10+%2B+3.14+*+R*R*R+*+2%2F3
</p>

<code>+</code> is used to stand for a blank, <code>%</code> introduces a hex encoding,<code>2B</code> is the ASCII code for <code>+</code>, and <code>2F</code> 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 ( . ).
</ul>

[[Category:Janus Web Server $functions|$Web_URL_Encode and $Web_URL_Encode_Lstr]]