| By Dimitre Novatchev |
| Language | XSLT |
| Category | designpatterns, xml, msxml, html |
| Posted | 20 Mar 2001 |
| Updated | 20 Mar 2001 |
| Summary |
| This snippet shows how to pad a given string with spaces to a given fixed length. Two non-recursive templates are presented. Demonstrated is how to specify white-space only nodes within a variable's contents. |
| This is a repeated FAQ: |
| "I have a string, which I need to pad with spaces so that the result will occupy exactly 10 characters. Can this be done with XSLT?" |
| The answer is an "yes" as demonstrated by the code below. |
| While a general recursive approach for iterating N times and outputting a space on each iteration, here we present another, non-recursive approach. |
| The idea is that if we know in advance the maximum length to which strings will have to be padded, then we could declare an xsl:variable holding a string of spaces with at least this maximum length. |
| The rest is just some simple calculation of lengths and using the substring function. |
| The code below performs right-padding a string. A very small modification is needed so that left-padding will be performed just change: |
| substring(concat($String,$spaces),1,$length) |
| to |
| concat(substring($spaces, 1, $length - string-length($String)), $String) |
| Another thing to note is the xml:space="preserve" in one of the definitions of the "spaces" variable. |
| Why is this necessary? As we know, the msxml3 parser discards on default all whitespace-only nodes. Without specifying the "preserve" value for the xml:space attribute, it would not be possible to specify the necessary number of spaces as a single text node within the contents of the variable. |
| Another thing to note is that if we intend to present the resulting padded string by a browser, we need to enclose it with <pre> (or <q>, or <blockquote>) tags, or translate all spaces to 
 so that the browser will not ignore the spaces. |
| code |
| XSL Stylesheet |
| XML/HTML Result: |
| Text Result: |