barcode generator github c# BUILDING XSLT APPLICATIONS in Font

Generator PDF 417 in Font BUILDING XSLT APPLICATIONS

If you haven t provided a second argument, then the XSLT processor will assume that the file is encoded as UTF-8 and interpret it accordingly. For example, to access the content of disclaimer.html as a string, with a default encoding of ISO-8859-1, you would use unparsed-text('disclaimer.html', 'ISO-8859-1')

Summary You can use the unparsed-text() function to access external text documents as a string. The first argument is the location of the text file, and the optional second argument is the default encoding for the file, used if no other information is available about its encoding.

If the processor has any problems locating the document that you ve specified when using the document() or unparsed-text() functions, then the processor can either return an empty sequence (or string for the unparsed-text() function) or halt the transformation altogether. The same thing happens if the document you point to with the document() functions turns out not to be an XML document. Most processors halt the transformation in these circumstances. Processors will also halt if the file you refer to with the doc() function isn t available or isn t an XML document. All this means you have to be quite careful that the file paths that you use do actually point to an existing document. You can test whether an XML document is actually available at a particular location using the doc-available() function. This takes a string URI as an argument and returns true if there s an XML document at that location and false if not. Usually, then, you would wrap a call to doc() or document() within an if statement that tested for the presence of an XML document before accessing it, and returned something useful (such as an empty sequence) if the document itself isn t available. For example: if (doc-available('flags.xml')) then doc('flags.xml') else () The doc-available() function isn t suitable for testing for the presence of documents you re going to open with unparsed-text(), since these documents usually aren t XML documents and therefore doc-available() will return false for them. Instead, the unparsed-text-available() function has a similar purpose: it takes a URI and, optionally, an encoding, and tests whether the document specified by the URI is readable. For example: if (unparsed-text-available('disclaimer.html', 'ISO-8859-1')) then unparsed-text('disclaimer.html', 'ISO-8859-1') else ''

Summary The transformation will usually halt if the external document that you ve indicated cannot be opened. The doc-available() and unparsed-text-available() functions allow you to test whether doc(), document(), or unparsed-text() will actually work.

To test out using information from external XML documents, we ll try to use the information from flags.xml to create the <img> element shown next to a program. The flags.xml document looks like <flags> <flag name="favorite" src="favorite.gif" alt="Favorite" /> <flag name="interesting" src="interest.gif" alt="Interest" /> </flags> In TVGuide5.xsl, when we process a program using the template matching <Program> elements in Details mode, we use the following code: <xsl:if test="@flag"> <img src="{if (@flag = 'favorite') then 'favorite' else 'interest'}.gif" alt="[{if (@flag = 'favorite') then 'Favorite' else 'Interest'}]" width="20" height="20" /> </xsl:if> Instead, in TVGuide6.xsl, we can try to retrieve the relevant <flag> element from the flags.xml document, and then process it to produce the flag graphic. The relevant <flag> element is the one whose name attribute has the same value as the value of the flag attribute of the current <Program> element: document('flags.xml')/flags/flag[@name = current()/@flag] If we simply apply templates to this <flag> element, then we won t get a graphic if no <flag> element was found, which is precisely what we want. So rather than testing whether a flag attribute is present, we can just apply templates to the <flag> element from the flags.xml document: <xsl:apply-templates select="document('flags.xml')/flags/flag[@name = current()/@flag]" /> Then we need a template that matches the <flag> element and produces the relevant <img> element. The value of the src attribute comes from the src attribute on the <flag> element, and the value of the alt attribute comes from the alt attribute on the <flag> element (you could simply copy them if you prefer): <xsl:template match="flag"> <img src="{@src}" alt="{@alt}" width="20" height="20" /> </xsl:template> The result of transforming TVGuide.xml with TVGuide6.xsl is TVGuide6.html, which is shown in Figure 12-9.