UDF/User defined function libreoffice basic with built-in help/tip - input

Question

I did a function in LibreOffice calc. It works, but I would like to have a conext help/tip capability, like the built in LibreOffice functions.
Example: when I type "=besselk(" it appaears a tip BESSELK(X; N). Using the function wizard a function and arguments description does also appear.
Besselk
besselk
Let's say I have a function to calculte a rectangle area
function arearect(a, b)
arearect = a * b
end function
I would like to have something like this:
function arearect(a, b)
FUNCTION DESCRIPTION "Compute rectangle area"
ARGUMENT DESCRIPTION "base length"
ARGUMENT DESCRIPTION "height"
arearect = a * b
end function
so, when I type "=arearect(" the argument description would appear and all descriptors would appear on Function Wizard.
thanks

Answer 1

Create the user-defined function as a Spreadsheet Add-In. Then enter the help text in the Description node in the .xcu file that defines the add-in.
For example, I created a function called REVERSE. Here is my CalcAddIns.xcu file:
<?xml version="1.0" encoding="UTF-8"?>
<oor:component-data xmlns:oor="http://openoffice.org/2001/registry"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
oor:name="CalcAddIns" oor:package="org.openoffice.Office">
<node oor:name="AddInInfo">
<node oor:name="name.JimK.ReverseStringImpl" oor:op="replace">
<node oor:name="AddInFunctions">
<node oor:name="reverse" oor:op="replace">
<prop oor:name="DisplayName"><value xml:lang="en">reverse</value></prop>
<prop oor:name="Description">
<value xml:lang="en">Flips a string backwards. For example "apple" becomes "elppa".</value>
</prop>
<prop oor:name="Category"><value>Add-In</value></prop>
<!-- This won't help, because there is no reverse() in Excel. -->
<prop oor:name="CompatibilityName"><value xml:lang="en">reverse</value></prop>
<node oor:name="Parameters">
<node oor:name="s" oor:op="replace">
<prop oor:name="DisplayName"><value xml:lang="en">s</value></prop>
<prop oor:name="Description"><value xml:lang="en">The string to reverse.</value></prop>
</node>
</node>
</node>
</node>
</node>
</node>
</oor:component-data>
An Add-In also requires some other files. Here is my XCalcFunctions.idl:
#include <com/sun/star/uno/XInterface.idl>
module name { module JimK { module CalcFunctions {
interface XCalcFunctions
{
string reverse( [in] string s );
};
}; }; };
The actual implementation was simple. I used python:
def reverseString(inString):
s = unicode(inString)
# This is extended slice syntax [begin:end:step]. With a step of -1,
# it will traverse the string elements in descending order.
return s[::-1]
The result:
EDIT:
There is another piece in Components.py for my extension:
class StringReverserAddIn(unohelper.Base, XCalcFunctions):
def __init__(self, ctx):
self.ctx = ctx
#staticmethod
def factory(ctx):
return StringReverserAddIn(ctx)
def reverse(self, inString):
from lingt.app.calcfunctions import reverseString
return reverseString(inString)
g_ImplementationHelper.addImplementation(
StringReverserAddIn.factory,
"name.JimK.LinguisticTools.ReverseStringImpl",
("com.sun.star.sheet.AddIn",),)
The file is declared in manifest.xml:
<!--- The Python code -->
<manifest:file-entry
manifest:full-path="Components.py"
manifest:media-type="application/vnd.sun.star.uno-component;type=Python"/>
The complete extension: https://extensions.libreoffice.org/extensions/lingtools.