1. Advanced Find and Replace with Regular Expressions
Robert Kiffe Senior Customer Support Engineer

2. Agenda Review: Global Find and Replace
Introduction to Regular Expressions
Challenge #1
Solution
Advanced Regular Expressions
Challenge #2
Hands On
Q & A

3. Global Find and Replace
Location: Content > Find and Replace
Administrators Only (User Level 10)
Searches a single site
Adjust ‘Scope’ to limit searchable content
Literal Text or Regex patterns

4. Global Find and Replace
Simple search with results list
Preview Replace
Safe multi-step process
Perform ‘sample’ find/replace and display results list
Select pages from results to perform the actual find/replace operation
(Optional) Publish selected results

5. Regular Expressions Regular Expression
A pattern that ‘describes’ a certain amount of text
The concept arose in the 1950s when the American mathematician Stephen Cole Kleene formalized the description of a regular language. (Thanks Wikipedia)
Now used in almost every major programming language

6. Literal Characters Literal Text Matches
Most characters match exactly themselves
Case Sensitive
Robert does not like to be called robert.
Robert does not like to be called robert.
Robert

7. Special Characters
Symbol characters that have special purpose (explained later)
Full List: \ ^ $ . | ? * + ( ) [ {
To match as literal characters, you must ‘escape’ them by adding “\” in front
Rob does not like to be called Robert?
Rob does not like to be called Robert?
Robert\?

8. Special Character: Period
‘Wildcard’ Character
Matches any character except newline.
Robert does not like to be called oberth, Bobert, or Goobert.
Robert does not like to be called oberth, Bobert, or Goobert.
.obert

9. Special Characters: Quantifiers
Symbol characters that define how many of the previous character(s) to match
? (0 or 1)
* (0 or More)
+ (1 or More)
Use Curly Brackets to indicate an exact number or range
{3} (Exactly 3)
{3,} (3 or More)
{3,5} (3, 4, or 5)
Only modifies the previous character (or group)

10. Special Characters: Quantifiers
Quantifiers: Example
? : 0 or 1
Robert does not like to be called Roberta.
Robert does not like to be called Roberta.
Roberta?

11. Special Characters: Parenthesis
Capture Groups
Encapsulate a character sequence using parentheses: “(…)”
Add a quantifier to affect the whole group
Replace
In the ‘replace field’, refer to your groups using the “dollar sign” and then the group number: $#
Count the opening parenthesis characters, “(” , to determine the correct #

12. Special Characters: Parenthesis
Capture Group: Example
FIND
I like but not
I like but not
REPLACE
I like but not

13. Challenge #1 Find All Links to a Particular Domain
Problem is that it can have many formats:
Root-relative “/”
/about/contact.html
Absolute (either protocol)
No Subdomain
Examples:
<a href="/about/">
<a href="

14. Challenge #1: Tips
Use a quantifier (ie. ‘?’) to make a part of the URL optional a?
Combine a quantifier with Parenthesis to make a substring of the URL optional
(abc)?

15. Challenge #1: Solution Steps to Build the Regex Pattern:
href="https?://www\.gallena\.com/ (HTTPS protocol)
href="https?://(www\.)?gallena\.com/ (+Subdomain optional)
href="(https?://(www\.)?gallena\.com)?/ (+Root-relative)
Example Matches:
<a href="
<a href="
<a href="/academics/index.html">Academics</a>
<a href=" Login</a>

16. Special Characters: Square Brackets
Character Sets
Characters encased inside square brackets define all possible matches for a single text character: [abc]
A quantifier placed directly after the set will affect the whole character set
Placing a “-” between characters indicates a ‘range’
Placing a “^” as the first item in the set creates a ‘negative pattern’
Quantifier characters become literal matches: ? + * { }
Period character becomes literal match: .

17. Character Sets: Examples
Robert does not like to be called robert.
Robert does not like to be called robert.
[Rr]obert
Robert does not like to be called Richard.
Robert does not like to be called Richard.
[A-Z][a-z]+
Robert does not like to be called Roberta.
Robert does not like to be called Roberta.
[^A-Z .]+

18. Shorthand Character Classes
Certain characters can reference a range of characters when ‘escaped’ by a backslash (\)
Common Examples:
\d matches all digit characters: [0-9]
\w matches all ‘word’ characters: [A-Za-z0-9_]
\s matches all ‘space’ characters (including line breaks)
Using the capital letter will ‘inverse’ the match
\S matches all non-space characters: [^\s]

19. Character Classes: Example
Jenny’s number is
Jenny’s number is
\d{3}-\d{4}

20. Greedy Matches
When using quantifiers, a careless (or purposeful) pattern could match beyond an expected result
Apply an extra coating of “?” after the initial quantifier, to make the pattern stop at the first successful match
Robert likes dogs! Robert likes cats!
Robert likes .*!
Robert likes dogs! Robert likes cats!
Robert likes .*?!

21. Challenge #2 Set External Links to Create a New Window
Need to add the attribute target="_blank"
Links will start with “http” or “https”
Examples:
<a href="
<a href="
Desired Result:
<a href=" target="_blank">OmniUpdate</a>
<a href=" target="_blank">Petitions</a>

22. Challenge #2: Tips Remember lessions learned from Challenge #1
(abc)?
Remember syntax requirements of HTML (or XML)
HTML/XML have special characters that can only be used in certain places
Use a “Not” to match any character not in the set
[^abc]
Use capture groups to re-place content as needed
(abc) -> $1

23. Challenge #2: Solution Steps to Build the Regex Pattern FIND: REPLACE:
<a href=" (Starting Pattern)
<a\s*href=" (Account for whitespace)
<a\s*href="https?://[^"]+"\s*> (Match any absolute URL)
(<a\s*href="https?://[^"]+"\s*)> (Capture Group)
REPLACE:
$1 target="_blank"> (Use capture group, then end anchor tag)
Example Match/Replace:
<a href=" (Full Match)
<a href=" (Capture)
<a href=" target="_blank">About</a> (Replace)

24. Thank you. Robert Kiffe Sr. Customer Support Engineer OmniUpdate
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