Selenium Concepts

Concepts

A command is what tells Selenium what to do. Selenium commands come in three 'flavors': Actions, Accessors and Assertions. Each command call is one line in the test table of the form:
command
target
value
Actions are commands that generally manipulate the state of the application. They do things like "click this link" and "select that option". If an Action fails, or has an error, the execution of the current test is stopped.
Many Actions can be called with the "AndWait" suffix, e.g. "clickAndWait". This suffix tells Selenium that the action will cause the browser to make a call to the server, and that Selenium should wait for a new page to load.
Accessors examine the state of the application and store the results in variables, e.g. "storeTitle". They are also used to automatically generate Assertions.
Assertions are like Accessors, but they verify that the state of the application conforms to what is expected. Examples include "make sure the page title is X" and "verify that this checkbox is checked".
All Selenium Assertions can be used in 3 modes: "assert", "verify", and "waitFor". For example, you can "assertText", "verifyText" and "waitForText". When an "assert" fails, the test is aborted. When a "verify" fails, the test will continue execution, logging the failure. This allows a single "assert" to ensure that the application is on the correct page, followed by a bunch of "verify" assertions to test form field values, labels, etc.
"waitFor" commands wait for some condition to become true (which can be useful for testing Ajax applications). They will succeed immediately if the condition is already true. However, they will fail and halt the test if the condition does not become true within the current timeout setting (see the setTimeout action below).
Element Locators tell Selenium which HTML element a command refers to. Many commands require an Element Locator as the "target" attribute. Examples of Element Locators include "elementId" and "document.forms[0].element". These are described more clearly in the next section.
Patterns are used for various reasons, e.g. to specify the expected value of an input field, or identify a select option. Selenium supports various types of pattern, including regular-expressions, all of which are described in more detail below.
Defines an object that runs Selenium commands.
Element Locators
Element Locators tell Selenium which HTML element a command refers to. The format of a locator is:
locatorType=argument
We support the following strategies for locating elements:
identifier=id: Select the element with the specified @id attribute. If no match is found, select the first element whose @name attribute is id. (This is normally the default; see below.)
id=id: Select the element with the specified @id attribute.
name=name: Select the first element with the specified @name attribute.
username
name=username
The name may optionally be followed by one or more element-filters, separated from the name by whitespace. If the filterType is not specified, value is assumed.
name=flavour value=chocolate
dom=javascriptExpression: Find an element by evaluating the specified string. This allows you to traverse the HTML Document Object Model using JavaScript. Note that you must not return a value in this string; simply make it the last expression in the block.
dom=document.forms['myForm'].myDropdown
dom=document.images[56]
dom=function foo() { return document.links[1]; }; foo();
xpath=xpathExpression: Locate an element using an XPath expression.
xpath=//img[@alt='The image alt text']
xpath=//table[@id='table1']//tr[4]/td[2]
xpath=//a[contains(@href,'#id1')]
xpath=//a[contains(@href,'#id1')]/@class
xpath=(//table[@class='stylee'])//th[text()='theHeaderText']/../td
xpath=//input[@name='name2' and @value='yes']
xpath=//*[text()="right"]
link=textPattern: Select the link (anchor) element which contains text matching the specified pattern.
link=The link text
css=cssSelectorSyntax: Select the element using css selectors. Please refer to CSS2 selectors, CSS3 selectors for more information. You can also check the TestCssLocators test in the selenium test suite for an example of usage, which is included in the downloaded selenium core package.
css=a[href="#id3"]
css=span#firstChild + span
Currently the css selector locator supports all css1, css2 and css3 selectors except namespace in css3, some pseudo classes(:nth-of-type, :nth-last-of-type, :first-of-type, :last-of-type, :only-of-type, :visited, :hover, :active, :focus, :indeterminate) and pseudo elements(::first-line, ::first-letter, ::selection, ::before, ::after).
ui=uiSpecifierString: Locate an element by resolving the UI specifier string to another locator, and evaluating it. See the Selenium UI-Element Reference for more details.
ui=loginPages::loginButton()
ui=settingsPages::toggle(label=Hide Email)
ui=forumPages::postBody(index=2)//a[2]
Without an explicit locator prefix, Selenium uses the following default strategies:
dom, for locators starting with "document."
xpath, for locators starting with "//"
identifier, otherwise
Element Filters
Element filters can be used with a locator to refine a list of candidate elements. They are currently used only in the 'name' element-locator.
Filters look much like locators, ie.
filterType=argument
Supported element-filters are:
value=valuePattern
Matches elements based on their values. This is particularly useful for refining a list of similarly-named toggle-buttons.
index=index
Selects a single element based on its position in the list (offset from zero).
String-match Patterns
Various Pattern syntaxes are available for matching string values:
glob:pattern: Match a string against a "glob" (aka "wildmat") pattern. "Glob" is a kind of limited regular-expression syntax typically used in command-line shells. In a glob pattern, "*" represents any sequence of characters, and "?" represents any single character. Glob patterns match against the entire string.
regexp:regexp: Match a string using a regular-expression. The full power of JavaScript regular-expressions is available.
regexpi:regexpi: Match a string using a case-insensitive regular-expression.
exact:string: Match a string exactly, verbatim, without any of that fancy wildcard stuff.
If no pattern prefix is specified, Selenium assumes that it's a "glob" pattern.
For commands that return multiple values (such as verifySelectOptions), the string being matched is a comma-separated list of the return values, where both commas and backslashes in the values are backslash-escaped. When providing a pattern, the optional matching syntax (i.e. glob, regexp, etc.) is specified once, as usual, at the beginning of the pattern.