Parameters in xactions are sent via GET-Method by default.
To enable POST-Method one has to make changes to the following files (which can be found in pentaho-solutions/system/custom/xsl):
DefaultParameterForm.xsl
Change <xsl:variable name="USEPOSTFORFORMS" select="'false'" />
to <xsl:variable name="USEPOSTFORFORMS" select="'true'" />
ParameterFormUtil.xsl
Change
[...]
<form>
<xsl:if test="$USEPOSTFORFORMS='true'">
<xsl:attribute name="method">post</xsl:attribute>
<xsl:attribute name="target">_blank</xsl:attribute>
<xsl:attribute name="action">ViewAction</xsl:attribute>
</xsl:if>
[...]
to
[...]
<form>
<xsl:if test="$USEPOSTFORFORMS='true'">
<xsl:attribute name="method">post</xsl:attribute>
<xsl:attribute name="target">_self</xsl:attribute>
<xsl:attribute name="action">ViewAction</xsl:attribute>
</xsl:if>
[...]
Refresh the repository and all parameters should be sent via POST-Method.