XSL November 4 Unit 6 xsl sort Default

XSL November 4, Unit 6

<xsl: sort> • Default sorting is based on text • However, we can also sort on numbers, more successfully than last class • <xsl: sort select = “price” data-type = “number”> • We use the data-type attribute to specify if we are sorting on text or numbers – Since text is default only need to add this when we want to sort based on a number • In this case, price.

<xsl: sort> on Multiple Tags • What if want to sort by price, then by author? – Or perhaps last name, then by first name? • We can use two <xsl: sort> elements to do this <xsl: sort select =“price” data-type = “number”/> <xsl: sort select = “author”/> • Another example: <xsl: sort select = “last_name”/> <xsl: sort select = “first_name”/> • When using multiple <xsl: sort> elements, the order is important – First sort by last_name, then sort by first_name – First sort by price, then sort by author

In-Class Example • Multiple Sorts • Including sorting by numbers

If • We can add conditional statements to our XSL file • “If the item is out of stock, display the item in red” • “If the cost is more than 6. 95, show me the book details” • “If the book is by C. S. Lewis, show me the books”

Using <xsl: if> • <xsl: if> must have the attribute test • Test is the expression we are testing – price > 6. 95 – author = “C. S. Lewis” – Inventory < 10 • <xsl: if> must have a closing tag – The contents of the <xsl: if> element should be the rules you want to apply • For instance, turn the color red

Using <xsl: if> Example <xsl: for-each select = “products/book”> <xsl: if test = “price < 19”> <h 3 style = "color: olive"><xsl: value-of select = "title"/></h 3> Author: <xsl: value-of select = "author"/> Price: $<xsl: value-of select = "price/> Inventory: <xsl: value-of select = "inventory/> Date: <xsl: value-of select = "publish. Date"/> </xsl: if> </xsl: for-each> *Will only display books which have a price less than $19. 00

Using <xsl: if> Example <xsl: for-each select = “products/book”> <xsl: if test = “inventory = 0”> <h 3 style = "color: olive"><xsl: value-of select = "title"/></h 3> Author: <xsl: value-of select = "author"/> Price: $<xsl: value-of select = "price/> Inventory: <xsl: value-of select = "inventory/> Date: <xsl: value-of select = "publish. Date"/> </xsl: if> </xsl: for-each> *Will only display books which are out of stock (inventory = 0)

Using <xsl: if> Example <xsl: for-each select = “products/book”> <xsl: if test = “author = ‘C. S. Lewis’”> <h 3 style = "color: olive"><xsl: value-of select = "title"/></h 3> Author: <xsl: value-of select = "author"/> Price: $<xsl: value-of select = "price/> Inventory: <xsl: value-of select = "inventory/> Date: <xsl: value-of select = "publish. Date"/> </xsl: if> </xsl: for-each> *Will only display books that have C. S. Lewis for an author

Using <xsl: if> Example <xsl: for-each select = “products/book”> <xsl: if test = “author != ‘C. S. Lewis’”> <h 3 style = "color: olive"><xsl: value-of select = "title"/></h 3> Author: <xsl: value-of select = "author"/> Price: $<xsl: value-of select = "price/> Inventory: <xsl: value-of select = "inventory/> Date: <xsl: value-of select = "publish. Date"/> </xsl: if> </xsl: for-each> *Will only display books that are NOT written by C. S. Lewis

Using <xsl: if> Example <xsl: for-each select = “products/book”> <h 3 style = "color: olive"><xsl: value-of select = "title"/></h 3> Author: <xsl: value-of select = "author"/> Price: $<xsl: value-of select = "price/> <xsl: if test = “inventory < 5”> Inventory: <xsl: value-of select = "inventory/> </xsl: if> <xsl: if test = “inventory > = 5”> Inventory: <xsl: value-of select = "inventory/> </xsl: if> Date: <xsl: value-of select = "publish. Date"/> </xsl: for-each> *Will display books that are fewer than 5 in stock in the color red any books with inventory > 5 in black

In Class Example • Using <xsl: if>

Operators • • • +, -. *, div : standard math operators = equal , can be used with numbers and text != not equal, used with both numbers and text < strictly less than, use < <= less than or equal to, use < = > strictly greater than, use > >= greater than or equal to, use > = or, “price = 9. 50 or price = “ 9. 60” and, “price > 9. 00 and price < 10. 00” mod, mathematical operator, provides the remainder after division. – e. g. 12 mod 5 = 2, 24 mod 7 = 3.

Choose • We could use several if statements to cover every possibility – If inventory is greater than or equal to 100, show in black – If inventory is greater than or equal to 50 and less than 100, show in blue – If inventory is greater than or equal to 5 and less than 50, show in green – If inventory is less than 5 show in red • Or we could use “xsl: choose”

<xsl: choose> • <xsl: choose> is combined with <xsl: when> and <xsl: otherwise> – Provides “if, else” • Basic format: <xsl: choose> <xsl: when test = “expression”> ………. . </xsl: when> <xsl: otherwise> ………. </xsl: otherwise> </xsl: choose>

Using Choose <xsl: for-each select ="products/book"> <h 3 style = "color: olive"><xsl: value-of select = "title"/></h 3> Author: <xsl: value-of select = "author"/> <xsl: choose> <xsl: when test="price > 6. 95"> Price: $<xsl: value-of select = "price"/> </xsl: when> <xsl: otherwise> Price: $<xsl: value-of select = "price"/> </xsl: otherwise> </xsl: choose> Inventory: <xsl: value-of select = "inventory"/> Date: <xsl: value-of select = "publish. Date"/> </xsl: for-each> *If the price is greater than $6. 95, display the price in red. Otherwise, display the price normally (in black)

Using Choose, cont. <xsl: choose> <xsl: when test = "inventory > =100"> Inventory: <xsl: value-of select = "inventory"/> </xsl: when> <xsl: when test = "inventory > =50"> Inventory: <xsl: value-of select = "inventory"/> </xsl: when> <xsl: when test = "inventory > =5"> Inventory: <xsl: value-of select = "inventory"/> </xsl: when> <xsl: otherwise> Inventory: <xsl: value-of select = "inventory"/> </xsl: otherwise> </xsl: choose> *If inventory is >= 100, display in navy. If 50<=inventory<100, display in blue. If 5<=inventory<50, display in green. If inventory<5, display in red.

In Class Example of Choose

Back to Templates • So far, we’ve only used a single template in our XSL files <xsl: template match = “/”> • But it is possible to have multiple templates, and can make the XSL easier to read • We will still have the <xsl: template match = “/”> element but now we can additional template elements

Making a New Template • Let’s add a new template which handles the information about the flowers in our bouquet <xsl: template match =“flower”> • Again, we use the <xsl: template> element • This time, though, we use match = “flower” to apply a template to the “flower” tag

Using Additional Templates • If we have multiple templates how do we use them? • We have to use the <xsl: apply-templates> • We can specify which templates to apply by using the select attribute • <xsl: apply-templates select = “flower. List”/>

In Class Example • Adding a template for “flower” • Adding a template for “price”

Validating XML • Can’t really validate XML like we can validate XHTML • We don’t have any rules stating what a <student> element can contain, or what it must contain • We have no way of knowing whether or not the tags were used properly • But, we can easily check for wellformedness

Well-Formedness • XML follows very strict rules – e. g. All tags must be closed – Tags must be properly nested • So we can check to be sure that our XML is “well -formed” • The basic syntax rules for XML can be verified for our document • There are well-formedness checkers online – Your browser will usually also tell you when you’ve got an error

Validating other XML Documents • If we have the rules for each tag and its attributes, we can completely validate our XML document – We can validate XHTML because the schema is online • We’ve had to specify where the “rules” for XHTML are in our doctype declaration at the top of the page • If we have a schema for our document, we should be able to validate it. • We can validate SVG and Math. ML

XHTML and HTML • XHTML is an XML schema – Set of XML tags, attributes, and rules – Browsers know how to read this XML schema • Older versions of HTML were not based on XML – Similar to XHTML but less strict • XHTML is identical to HTML 4. 01 – HTML 4. 01 was last non-XML-based HTML standard developed – Only change between HTML 4. 01 and XHTML 1. 0 was that the tags and attributes had to conform to XML rules • All tags and attributes are identical

XHTML 1. 1 • This course covers XHTM 1. 0 • But, there is a newer version, XHTML 1. 1 – Needs the MIME type application/xhtml+xml • Proper MIME type for XHTML documents • But, some browsers don’t recognize this type (IE especially) • This is why we use. html and not. xhtml for our file extensions • There is no transitional version of XHTML 1. 1 – No deprecated tags or attributes • XHTML 1. 1 requires the use of the xml: lang attribute instead of the lang attribute we covered earlier – Most browsers again do not support this yet • XHTML 2. 0 will be the next standard

Questions?