String replace() function in BPEL XSLT

First of all a very Happy New Year to all the readers and the readers to come. May this year brings more prosperity and unending happiness for all across the globe.

This post originates from my recent cerebral exercise of pondering over the best way to replace the occurrence of a string inside another string in XSLT. Especially in BPEL which doesn't have this inbuilt string-replace() function and hence we're bound to have something of our own, this was worth thinking. However, this resulted in additional findings too but with due respect to this post I'd like to keep them with me for the time being. So following lists the ways to have something of our own that can do string replacement. You can choose the best way based on your requirements.

• Write an XSLT template for string replace function and call this template whenever string replacement is required.
• Create your own Custom XPath function for String replacement that can be imported in JDeveloper and used across the whole developer team
• Harness the capabilities of using Java classes in XSLT. This is the simplest method and I'll explain this in just 2 steps, attributed to its simplicity.
• Create a namespace in XSLT for the Java String class to be used (let's prefix this as  :strClass).
• Use replaceAll() function of the String class referenced above as highlighted under. And the job is done.

Please note that any function of the String class can be used above and also any of the Java classes can be referenced in the similar way e.g. Math, DOMParser, Integer etc.

Once again Happy New Year and Happy Learning....

Inserting a New Line character in message using BPEL XSLT

In a requirement, we were trying to format the data fetched from DB (in XML format in BPEL) into a String variable with a new line inserted after each record. So that the data below would appear in the String variable like Following is the simple transformation to achieve the same.

<xsl:for-each select="/ns0:SelectFromLookupOutputCollection/ns0:SelectFromLookupOutput">
<xsl:value-of select='concat(ns0:property_name, ",", ns0:property_value,"&#10;")'/>
</xsl:for-each>

Key Points to Note:

• The magic lies in the word &#10; which serves as a new line character in XSLT (11g). In above case, it gets appended at the end of each record resulting in new line at the end of each record.
• The function somehow doesn't work in SOA Suite 11.1.1.3 (BUG-13602524, thanks to my colleague Nivea for identifying this) but works in 11.1.1.4 and older versions.

Validating incoming String of Date format using Regular Expression

I was recently trying to restrict the format of the incoming variable so as to adhere it to the date format like 27-Nov-2010 04:17:37 PM. Well, this had to be pretty simple by using the xp20:matches function that can be used to match a string pattern against a regular expression. I used my function as

xp20:matches(bpws:getVariableData('inputVariable','payload','/ns3:PropertyDetails/ns3:PropertyValueToUpdate'), '^(0[1-9]|[12][0-9]|3[01])[- /.](Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[- /.](19|20)\d\d (0[1-9]|1[012])[:](0[1-9]|[12345][0-9])[:](0[1-9]|[12345][0-9]) (AM|PM)$')

Ooops. This was not working and but telling me Internal Xpath Error. Well the reason was that getVariableData() function gets the data from the XML schema element in Object format rather than in String. Finally, all I did was that I used the string() function to convert the object from variable data and it worked without any issue.

xp20:matches(string(bpws:getVariableData('inputVariable','payload','/ns3:PropertyDetails/ns3:PropertyValueToUpdate')), '^(0[1-9]|[12][0-9]|3[01])[- /.](Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[- /.](19|20)\d\d (0[1-9]|1[012])[:](0[1-9]|[12345][0-9])[:](0[1-9]|[12345][0-9]) (AM|PM)$')

Just a small learning…