Use Inkscape and XSLT to Create Cross-Platform Reports and Forms
Listing 5. A Portion of the PHP Script That Transforms the Claim XML into an SVG and Displays It in a Browser
// import the SVG XSLT $xsl = new XSLTProcessor(); $xsl->importStyleSheet(DOMDocument::load("svg_xslt.xsl")); // load the claim data XML // $claim is the database result from Listing 4 $doc = new DOMDocument(); $doc->loadXML($claim); // tell the browser this is an SVG document header("Content-Type: image/svg+xml"); // print the SVG to the browser echo $xsl->transformToXML($doc);
Listing 5 is a simplified version of our solution. In our solution, there is the possibility of having multiple pages for a single claim. To fix this, we had to do multiple transformations, one for each page. To get the multiple-page claims to display in the same browser window, we had to embed them. This can be done using the embed and object HTML tags. Note that there are several issues with browser compatibility when using these tags. To solve the compatibility issues, we wrote a script that checks the user's browser and decides which tag to use. Then, we set the target object data/embedded source to a script similar to the one in Listing 5. This allowed the Web browser to display multiple SVG images in the same window.
Other considerations must be made when using SVG images in a Web browser environment. Internet Explorer does not have native support for SVG images. The user is forced to use a third-party plugin to display the images. Adobe provides one of these for free. Mozilla Firefox has built-in support for SVG images starting with version 1.5. However, Firefox does not support several aspects of SVG images, such as scaling and grouped objects. Fortunately for us, all of our users use an up-to-date version of Firefox.
That is all there is to it. Figure 5 shows a claim image with all of the data filled in.
Once we finished the Web end of our solution, we turned our sights toward the rest of our integration. This meant we had to print the SVG images and find a way to archive them. Some clients request that we send them copies of the claims printed and/or electronically. Because all of our back-end software is written in Python, it also meant we had to do the XML transformation in a different language. To do all of the XML work, we used the 4Suite XML API.
To print the images, we again turned to Inkscape, because our PostScript printer drivers would not print the SVG images. Inkscape has a handful of command-line options that tell Inkscape to run in command-line mode, thus suppressing the graphical interface. The one we used to print is the -p option. This, combined with the lpr command, allowed us to print our images without any user interaction. Listing 6 shows how we did the same transform we did in Listing 5, except now in Python. The example also shows how we called Inkscape to print our claim images.
Listing 6. Same Transform as Shown in Listing 5, Except Using Python
from Ft.Xml.Xslt import Processor from Ft.Xml import InputSource from Ft.Xml.Domlette import NonvalidatingReader // load the claim data XML // claim is the database result from Listing 4 doc = NonvalidatingReader.parseString(claim, "http://spam.com/doc.xml") // load and process the XSLT xsl = InputSource.DefaultFactory.fromUri("file://svg_xslt.xsl") processor = Processor.Processor() processor.appendStylesheet(xsl) // do the transformation result = processor.runNode(doc, "http://spam.com/doc.xml") // write the SVG to a file f = open("/tmp/"+ claim +".svg", "w") f.write(result) f.close() // print the image on the default printer os.system("inkscape /tmp/"+ claim +".svg -p | lpr")
Earlier, I mentioned we often have multiple pages per claim. When printing, this was not an issue; we simply would send each page to the printer as a separate job. When it came to archiving, we had to do something different. As with the Web interface, we had to group the pages, this time into a file, not a Web browser. When archiving, we had to store the files in PDF format, because that is what our clients wanted. To get the images into a PDF and combine the multiple page claims, we used Inkscape and Ghostscript.
As with printing, Inkscape has an option to export a file into PostScript format. Instead of using -p, we use -P and pass Inkscape the desired output filename. After all of the pages of a claim have been written to files, we use the following Ghostscript command to put the pages into a single PDF and archive them:
gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=out.pdf /tmp/foo1.ps /tmp/foo2.ps
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