About

This project implements in pure XSLT 2.0 some of the concepts introduced by Log4j (https://logging.apache.org/log4j/2.x/), a popular Java library for logging.

This library provides in same flavour as Log4j:

enabling /disabling logging
set different levels of information
time stamp

Background

In XSLT there is

xsl:message

to output logging information to the console.

But this is limited and there is no more detailed logging mechanisms out of the box

This was the reason what I wrote this.

Requirements

This was tested with Saxon HE parser (http://saxon.sourceforge.net/) Any XSLT2.0 compliant parser should produce same output.

Installation

For easiness you can add this project as git submodule of your project and use it from there but you can use any path.

Import log4xslt.config.xsl file (example below using submodule)

<xsl:import href="log4xslt/log4xslt.config.xsl"/>

Already imported from above file are:

common.variables.xsl: provides useful string variables
common.templates.xsl: provides common templates

Configuration

Logger Level

Set a parameter at the beginning of your XSLT with desired level:

<xsl:param name="LOGGER.LEVEL">INFO</xsl:param>

This will have precedence over what is set inside the library (where level is ALL)

Possible values in order of visibility (taken from log4j.dtd) are:

ALL,TRACE,DEBUG,INFO,WARN,ERROR,FATAL,OFF,NULL

Parameters

Additionally, template common.INFO will look for up to 5 parameters (p1.. p5), which can be redefined at your XSLT.

<xsl:param name="p1"></xsl:param>
<xsl:param name="p2"></xsl:param>
<xsl:param name="p3"></xsl:param>
<xsl:param name="p4"></xsl:param>
<xsl:param name="p5"></xsl:param>

Message Format

if really needed, you can adjust message FORMAT in log4xslt.config.xsl

(this shall be also configurable from outside in future versions)

Tests

See inside test subfolder: example.xml and example.xsl files

example.xsl :

adjust param LOGGER.LEVEL to different levels to see output.
adjust params p1.. p5 to see how common.INFO template works

sample output

java -jar  -s:example.xml -xsl:example.xsl  -o:example-output.xml

2019-08-15+02:00        09:54:57.309876+02:00   INFO    LOGGER level:INFO
2019-08-15+02:00        09:54:57.309876+02:00   INFO    XSLT version:3.0
2019-08-15+02:00        09:54:57.309876+02:00   INFO    XSLT Processor:Saxonica-HE 9.9.1.1
2019-08-15+02:00        09:54:57.309876+02:00   INFO    param $p1:
2019-08-15+02:00        09:54:57.309876+02:00   INFO    param $p2:
2019-08-15+02:00        09:54:57.309876+02:00   INFO    param $p3:abcd
2019-08-15+02:00        09:54:57.309876+02:00   INFO    param $p4:
2019-08-15+02:00        09:54:57.309876+02:00   INFO    param $p5:
2019-08-15+02:00        09:54:57.309876+02:00   WARN    this is just a copy
2019-08-15+02:00        09:54:57.309876+02:00   ERROR   just to show the level, not error actually
2019-08-15+02:00        09:54:57.309876+02:00   WARN    this is just a copy
2019-08-15+02:00        09:54:57.309876+02:00   WARN    this is just a copy
2019-08-15+02:00        09:54:57.309876+02:00   ERROR   just to show the level, not error actually
2019-08-15+02:00        09:54:57.309876+02:00   WARN    this is just a copy

License

MIT - See LICENSE

ukuko/log4xslt