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10. The barcodes and dynamic images example explained

The personCard.xre example in the database which shows how to:

  • use barcodes
  • dynamically select an image

This example creates a personal card with the name and address of a person together with the photo and a barcode which encodes the name of the person. The input file is a XML file with a list of persons and their information, the schema of the XML file is very simple:


The card has been split in 4 columns, the first one contains the photo and the last one contains the barcodes. These are the 2 objects we are interested in.

The image object could be a static image file if you enter a file name in the image field, however in this example we want to select a different image for each person (the photo), so we use the xpath field and enter the value concat('examples/barcodes/foto_',id,'.PNG').

This expression concatenates the 3 values:

  • examples/barcodes/foto_
  • id of a person
  • .PNG

Since one of the persons has the id 12345 the result for that person will be examples/barcodes/foto_12345.jpg. So that is the file that will be used as photo for that person.



Note that we used the id instead of /list/person/id in the concat function. Since the XMLNode of the detail area (the card) is /list/person, we have to use the value id to find the correct value for the current person.

The barcode is the second interesting object in this example. When you add a barcode to your document the barcode type selection window will popup. At this point you have to decide if it will be a 1D barcode (e.g. EAN or Code128) or a 2D barcode (Datamatrix, PDF417 ...).

Once the barcode is in your document you can distinguish 2 kind of properties:

  • In the Data section you can find properties which are common to all barcodes types. These are:
    • XPath: as with other objects this is the location in the XML document where the information for the barcode can be found. This is the information to be encoded in the barcode, in our example the name of the person.
    • Binary base64: this is required if you are going to encode binary data. In this case the XML document must contain base64 encoded binary data and the xpath field must point to a XML node which contains Base64 encoded data.
    • Process tilde: if true the tilde character (~) will be processed accordingly. Please refer to the specific barcode documentation (see link below).
  • In the Format section the barcode type specific properties are located. In this Datamatrix example, you can see the datamatrix encoding and format properties. You

can find more information about the barcode specific properties here http://www.java4less.com/barcodes/barcodes.php?info=guide