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In the recent days I have been working on XSl.
I have summarized about XSL just in terms of Syntax and usage in this page.
eXtensible Stylesheet Language Transformation:
Its a Stylesheet Programming language which is used to format a html file. We cannot display an XML document as such in a web browser. It has to be formatted. In short we can call this as a XML based Stylesheet language.Its similar but a bit advanced to CSS (Cascading Style Sheet). XSL is bit complex in understanding as it is more of declarative language. Most common belief that a programmer has in his mind will not work with XSL.
For e.g.: Variable is more of a constant here. I will explain it in details in the coming sessions.
Namespace in XSL:
You can have your own namespace declared in the stylesheet or you can use a generalized namespace say “XSL”
Lets see the how it can be declared:
<xn:stylesheet xmlns:xn = “http://www.w3.org/1999/XSL/Transform”></xn:stylesheet>
How to declare a function is xsl:
In XSL functions are called as templates. You can use templates to separate the content and presentation.
Lets see how to declare a template:
<xn:template name="templatename">
</xn:template>
How to call template from the main template:
<xn:call-template name="template"/>
How to pass parameters to template:
<xn:call-template name="template">
<xn:with-param name="paramname" select="param value”/>
</xn:call-template>
How to access the parameters in the template:
<xn:template name="templatename">
<xn:param name="paramname"/>
</xn:template>
Now you have the parameter in your template. If you want to use it you can use it with the parameter name with $ in front of it.
For eg: if you want to get a substring after a new line character in the template. You can do like this
substring-after($paramname,' '& #xa;')
Variables in XSL:
Variables in XSL are bit confusing to the users who work with High Level languages. Here variables are equivalent to “Constants” in most other languages. Once you declare a variable it cannot be modified in future. It can be used as a reference to actual value as in case the value is changed in future, it will reduce the rework time.
How to declare a variable in XSL:
<xn:variable name=”variablename” select=”value”/>
<xn:variable name=”variable”>value</xn:variable>
For-eg:
<xn:variable name=”user” select=”Dhanesh”/>
IF in XSL:
In Xsl if statement can be used to check some particular condition. If doesn’t have an else statement.
How to use if:
<xn:if test="condition”>
</xn:if>
For-e.g.
<xn:if test=”string-length($variable) & gt; 0”)>
<!—do some thing-->
</xn:if>
How to Use If else in XSL:
There is no direct if else statement in XSL. Still we can use another option when, otherwise.
Syntax:
<xn:choose>
<xn:when test="condition ">
<!—do some thing-->
</xn:when><xn:otherwise>
<!—do some thing-->
</xn:otherwise>
</xn:choose>
For Eg:
<xn:choose>
<xn:when test="contains($string,’:’)">
<!—do some thing-->
</xn:when>
<xn:otherwise>
<!—do some thing-->
</xn:otherwise>
</xn:choose>
For each in XSL:
If you have an array of elements or attributes and if you want to iterate with in the array is to use for each.
<xn:for-each select="IteratingArray">
</xn:for-each>
Some function used in XSL:
1) substring-after($variable-name,’delimiter’)
Retrieves the string after the delimiter in the variable
2) substring-before($variable-name,’delimiter’)
Retrieves the string before the delimiter in the variable.
3) contains($variable-name,’delimiter’)
Return if the delimiter is there in the variable or not
4) string-length($variable-name): Return the length of the string.
Please let me know if there is any modification ,Corrections or suggestion in this post .
