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jhubackova13-Aquamarine
13-Aquamarine
November 23, 2017
Solved

How to use XPath expression in Edit APP source in _ufe element?

  • November 23, 2017
  • 2 replies
  • 9097 views

Hello, I want to use _ufe element with universal definition of the colour.
The actual colour will be set in the xml document, e.g. in the <productname> element and his "role" attribute.

I changed the APP source for _ufe by this way:

...
//var color_value = '#0c6979';
var color_value = formating.evaluateXPath("//productname/@role");

 

// Print/PDF properties
style.color = ( color_value )
...

but it doesnลฅ work. Maybe the formating.evaluateXPath function doesn't return a string value?
The attempt with the direct setting of the color (a commented row) works OK.

 

Thanks for help

Jana

Best answer by GarethOakes

I haven't done this for a while, but there always used to be problems with XPath in generated content. Essentially the XPath couldn't properly "see" the document tree when running inside the generated content.

 

There are a couple of solutions:

  1. Store the colour value in a variable and use it later on
  2. Try prepending xml0# to the XPath

For #1, you would have to add a source edit in the root element to save the colour value. e.g. application.variables.myColour = formatting.evaluteXPath("/my/xpath"); Then you can use application.variables.myColour in your generated content source edit.

 

For #2, we're trying to trick APP to "see" the correct XML stream. The in-memory APP document will have a number of streams (headers, footers, and main text). The main text used to be called "xml0" hence the special syntax to direct the XPath to the correct location. e.g. formatting.evaluateXPath("xml0#/my/xpath");

2 replies

G
GarethOakes16-Pearl
16-Pearl
November 24, 2017

You will need to read the FOM documents to get the exact return values, although I think formatting.evaluateXPath() should return a string. The fxDocument (DOM) version of evaluateXPath certainly returns an object though. Your code otherwise looks mostly fine and should do what you're after.

 

Ideas:

  1. Check what the result string is: formatting.write( formatting.evaluteXPath("/whatever") );
  2. Don't use // at the start of an XPath expression. This causes the formatter to search the *entire* document everytime and slows formatting/printing down. Instead you should use a direct path e.g. /document/path/to/productname/@role
J
jhubackova13-AquamarineAuthor
13-Aquamarine
November 27, 2017

Hi Gareth, thanks for your tip,  I checked the expression and it returns correct value (e.g. in generated text). But whenever I use it in the APP source edit it doesn't work. The colour of the text is stil in black or it doesn't appear at all.

Jana

 

XPath in APP source.png

J
jhubackova13-AquamarineAuthor
13-Aquamarine
November 27, 2017

Hello, I found the different behaviour - whenever I use this _ufe element (with xpath expression) in the common text it works correctly. 

But when I use this same _ufe element  in the "Generated Contents" in the Page Region (and it is area when I need it ๐Ÿ™‚ it doesn't work at all.  

Do you have any idea how to solve it?  Sorry I'm not very skill in FOM/DOM syntaxe ...

 

Thanks  Jana

 

 

G
GarethOakes16-PearlAnswer
16-Pearl
November 27, 2017

I haven't done this for a while, but there always used to be problems with XPath in generated content. Essentially the XPath couldn't properly "see" the document tree when running inside the generated content.

 

There are a couple of solutions:

  1. Store the colour value in a variable and use it later on
  2. Try prepending xml0# to the XPath

For #1, you would have to add a source edit in the root element to save the colour value. e.g. application.variables.myColour = formatting.evaluteXPath("/my/xpath"); Then you can use application.variables.myColour in your generated content source edit.

 

For #2, we're trying to trick APP to "see" the correct XML stream. The in-memory APP document will have a number of streams (headers, footers, and main text). The main text used to be called "xml0" hence the special syntax to direct the XPath to the correct location. e.g. formatting.evaluateXPath("xml0#/my/xpath");

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