Selenium IDE: Pattern matching

Patterns are bread and butter of Selenium tests. Many commands in Selenium take the pattern parameter. They enable you to match various content types on a web page – links, text, elements. There are chiefly three type of patterns you can use in your tests: globs, exact and regular expressions.

Globs

Globs or the verb Globbing is familiar to most people who have ever used file matching patterns. If you have ever searched for a file in Linux or DOS using a line like *.exe or photos*, then you have used globs. But globbing in Selenium is not as rich as the one in Linux – it supports only three special characters: *, ? and [ ].

* matches any number of characters, by any we mean ‘nothing’, ‘a single character’ or ‘many characters’.

? , matches a single character.

[ ] , called a character class, lets you match any single character found within the brackets. e.g

[0-9] matches any digit
[a-zA-Z] matches any alphabet, regardless of case

To specify a glob in a selenium command, prefix the pattern with the glob: string. For example if you would like to search for the texts color or colour then you can use the colo*r glob as shown below.

Command	Target	Value
clickAndWait	link=search
verifyTextPresent	glob: colo*r

However you are free to eliminate the glob: prefix and only specify the text pattern because globbing patterns are the default in Selenium.

Regular Expression patterns

Of the three type of patterns, Regular Expressions are the one that are the most useful. Selenium supports the complete set of RegEx patterns that Javascript supports. So now you are not limited by the *,? And [] globbing patterns. To use RegEx patterns you need to prefix each RegEx with either regexp: or regexpi:, the latter being case-insensitive.

For example the following will test if a input field with the id ‘name’ contains the string ‘javascript’, ‘JavaScript’ or ‘Javascript’.

Command	Target	Value
clickAndWait	link=search
verifyValue	id=name	regexp:[Jj]ava([Ss]cript)

Below are a few common regular expression patterns:

regexp:(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)\d\d
:match a date in ‘mm/dd/yyyy’ format with any of the ‘-‘, ‘/’, ‘.’ as separators.

regexpi:^[A-Z0-9+_.-]+@[A-Z0-9.-]+$
:match a generic email address.

regexp:^[0-9]{5}(?:-[0-9]{4})?$
:match a ZIP code (U.S. postal code), allowing both the five-digit and nine-digit (ZIP + 4) formats.

regexp:^(?!000|666)(?:[0-6][0-9]{2}|7(?:[0-6][0-9]|7[0-2]))-?(?!00)[0-9]{2}-(?!0000)[0-9]{4}$
:match U.S Social Security numbers in the in the AAA-GG-SSSS format.

regexp:^(https?|ftp|file)://.+$
:match almost any url.

Exact Patterns

Patterns with the prefix ‘exact:’ will match the given text as it is. For example if you give the search pattern as below, then it will match a glob pattern ‘*’ or ‘*.java’.

Command	Target	Value
clickAndWait	link=search
verifyValue	glob: *.java

But if you want an exact match with the value string, i.e without the glob operator doing its work, you use the ‘exact’ pattern as below. In this example the ‘*’ (asterisk) will work as a normal character rather then a pattern-matching wildcard character.

Command	Target	Value
clickAndWait	link=search
verifyValue	exact: *.java

In conclusion the glob: and the exact: pattern are the subsets of the Regular Expression pattern matcher. Everything you can do with glob: or exact: you can accomplish with RegExp.