Icsug conf 14_dev03_xpages-roadtodamascas-lotus-script-and-formula-to-ssjs

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The Road to Damascas– A Conversion Experience:
LS and @Formula to SSJS
2014/03/17 –Matthew Fyleman

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Matthew Fyleman
21 Years as a Notes/Domino Developer
Mostly Working on:
Xpages conversions
Product development
Who Am I?

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Based on My Experiences
Converting LotusScript and @Formula to SSJS
Tools that can help –particularly regular expressions
What is this Talk About?

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When should you convert existing code?
Conversion Options
NotesAgent.run() with parameter doc
Search and Replace
Dedicated Tools
Preparation
Introduction to Regular Expressions
Examples and Demonstration
Tips and Traps
Dedicated Tools
Questions
What am I talking about?

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Never!
When should you convert existing code?

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What is the problem?
It is always going to be slow
GIGO
You will introduce new bugs
Re-developing will be quicker, cheaper and you will end up with a better result
But if you really must ...
When should you convert existing code?

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What are your options?
NotesAgent.run()
Quick and Dirty
Agent must run independently
Only use when agents are available and time is critical
LotusScript -> JavaScript (and Java)
Less useful for @Formula
Dedicated Tools
@Formula
Conversion Options

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Search and Replace is most useful for LS conversion
Syntactically similar
Easiest if you do a little refactoring first
Option Declare
doc.field(0) -> doc.getItemValue(“Field“)(0)
Camel Case Notes Objects
Make Sure Method calls are consistently named
Best to Avoid All-In-One-Go
Function or Sub at a Time
Variable with one purpose in one location may have a different use elsewhere
Converting LotusScript to SSJS -Preparation

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Regular Expressions are your new BFF
Sophisticated Pattern Matching
Elements from search can be carried through to replace
The Search and Replace built in to DDE can use Regular Expressions
Useful outside LS conversion (e.g. Validation)
See Planet Lotus -http://planetlotus.org/profiles/ross-swick_97733
Regular Expressions

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Tidy up first –Option Declare, remove clustering e.g.:
Dim xas Integer,yas Integer,zas Integer
We want to match any variable name in the pattern:
Dim <varname> As <Any valid type>
Fairly simple:
Dim[ ]+[A-Za-z0-9_]+[ ]+As[ ]+(Integer|String|Boolean|Double|Variant)
But how do we replace?
Modify the search:
Dim[ ]+([w]*)[ ]+As[ ]+String
Use this for replace
var1 = “”;
Starting Simple –Dim Statements

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For Notes Objects, Things are simpler
Dim <varname> As Notes<rest of object name>
-Ignore ... As New NotesSessionfor now
Also, initialising in SSJS, = null is ok:
var<varname>:Notes<rest of object name> = null;
So our terms are:
Search:
Dim[ ]+([w]*)[ ]+As[ ]+(Notes[w]*)
Replace:
var1:2 = null;
Starting Simple –Dim Statements (2)

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For the most part, simple S & R (but order is important):
End If to}
[ ]*Thento) {
Else[ ]+If[ ]*to } else if (
If[ ]* to if (
But what about:
If (x = 10) Then
Use Search: If[ ]+([w()[].<>" ]*)=([w()[].<> "]*)[ ]+Then
Use Replace: if (1==2) {
NB: Works but not optimal!
Other comparison operators not a problem
A bit more complex –If Statements

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The problem:
Session object is global in ssjs: ‘session’
In LS it is created:
Dim sessAs New NotesSession
Need to find all LS session objects, and replace with session
How do you get a list of session object names?
! –session objects
You need a coffee!

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Java String Object has regexsearch and replace
String source = “Dim x As String”;
String result = source.replaceAll(“Dim[ ]+([w]*)[ ]+As[ ]+String”, “var$1 = “”;”);
Pattern and Matcher objects make this even more powerful
Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(this.source);
intstartPos= 0;
while (m.find(startPos)) {
if (!itemList.contains(m.group(1))) {
itemList.add(m.group(1));
}
startPos= m.end() + 1;
}
Adding Java

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Similar Issue to Session
Need to find all document object names, and replace field handling methods
Will probably need to handle dot notation
Arrgghh!
How do you search for dot notation?
<doc name>.([^GetItemValue])([0-9]+)
Still hard work!
Field Handling

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There are other types than string!
Always review and test converted code thoroughly
Date handling is a pain
Script libraries can help here –Java?
Watch out for User interaction and particularly dialogues
Work out your strategies in advance!
Search and Replace –Tips and Traps

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In some respects @Formula -> SSJS is easier than LS -> SSJS
@Formula JavaScript Wrappers help a lot
Mostly just ‘;’ to ‘,’, and converting lists to arrays
Some constructions are obvious:
@SetField(“Field”, Value);
Goes to:
doc.replaceItemValue(“Field”, Value);
Or
S: @SetField([ ]*([w”]*)[ ]*,[ ]*([w”]*)[ ]*);
R: doc.replaceItemValue(1, 2);
But there are some issues ...
Converting Formula
@

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No direct equivalent in SSJS for *+, *= *>= etc. when applied to Lists
Need to plan for this
Java Class/Library to provide direct substitute
Unfortunately, Java does not permit operator overloading, so has to be a set of methods
Converting Formula –List Processing
@!

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@If(@Contains(_WFData_neu;_Key);"";
@Do(
@Set("_Sachgebiet_Zuordnung";@DbLookup("NOTES":"NOCACHE";"":_ADM$StructureDB;"Workflows";"WFArbeitsanweisung";"Sachgebietzuordnung"));
@If(_Sachgebiet_Zuordnung = "" | !@Contains(_Sachgebiet_Zuordnung;_Key2);@Do(
@Prompt([Ok];"Hinweis";"In der System Struktur VBM wurde für das aktuelle Sachgebiet kein Workflow definiert. Das Dokument wird zum ehemaligen Kompetenzträger zurückgegeben, damit dieser ein neues Sachgebiet auswählen kann.");
@Set("_Kompetenzträger";Bearbeiter1);
@Set("_tmpintern";5)
);
@Do(
@Prompt([Ok];"Hinweis";"In der System Struktur VBM wurde für das aktuelle Sachgebiet ein neues Sachgebiet konfiguriert. Das Dokument wird zum Kompetenzträger zurückgegeben, damit dieser das neue Sachgebiet auswählen kann.");
@Set("_neues_Sachgebiet";@Left(@Right(_Sachgebiet_Zuordnung;_key2);"||"));
@Set("_Elements";@Elements(@Explode(@Left(@Left(@Right(_WFData_neu;"||Sachgebiet#");"||"); _neues_Sachgebiet) + _neues_Sachgebiet; "$" )));
@Set("_KompetenzträgerData";@Explode(@Left(@Right(_WFData_neu;"||Kompetenzträger#");"||"); "$"));
@Set("_Kompetenzträger";@Subset(@Subset(_KompetenzträgerData;_Elements);-1));
@Set("_tmpintern";6)
)
)
)
);
Converting Formula -@If, @Do and @While
@!!!

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Search and Replace can be used for @Formula -> SSJS ...
... but it can only take you so far
A dedicated parser can go further
Only real alternative to manual translation for complex statements
Time consuming to create
Still not a silver bullet
Parsers

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Espresso -http://www.ultrapico.com/Expresso.htm
Good for learning regex, and serious regexdev
Free!
PowerGREP
Sophisticated regexfile search
Where regexstarted (UNIX grep)!
Expensive
Dedicated Tools

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We4IT –www.we4it.com
OpenNTF–www.openntf.org
RegexQuick Reference
http://www.night-ray.com/regex.pdf
Loads of websites for all aspects of regexdevelopment
Mastering Regular Expressions –Jeffrey E.F. Friedl– O’Reilly Publishing
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