Official locator strategies for the webdriver

Yes, you saw it right.

As per the current WebDriver - W3C Candidate Recommendation the Locator Strategies enlisted are as follows :

• "css selector" : CSS selector
• "link text" : Link text selector
• "partial link text" : Partial link text selector
• "tag name" : Tag name
• "xpath" : XPath selector

Snapshot :

However, the JsonWireProtocol was once used to support the Locator Strategies enlisted below but currently the documentation clearly states it's Status as OBSOLETE :

• class name : Returns an element whose class name contains the search value; compound class names are not permitted.
• css selector : Returns an element matching a CSS selector.
• id : Returns an element whose ID attribute matches the search value.
• name : Returns an element whose NAME attribute matches the search value.
• link text : Returns an anchor element whose visible text matches the search value.
• partial link text : Returns an anchor element whose visible text partially matches the search value.
• tag name : Returns an element whose tag name matches the search value.
• xpath : Returns an element matching an XPath expression. The provided XPath expression must be applied to the server "as is"; if the expression is not relative to the element root, the server should not modify it. Consequently, an XPath query may return elements not contained in the root element's subtree.

Snapshot :

The change was propagated through the respective client specific bindings. For the Selenium-Java clients here is the client code where we have the switchcase working for the users :

        switch (using) {
          case "class name":
            toReturn.put("using", "css selector");
            toReturn.put("value", "." + cssEscape(value));
            break;

          case "id":
            toReturn.put("using", "css selector");
            toReturn.put("value", "#" + cssEscape(value));
            break;

          case "link text":
            // Do nothing
            break;

          case "name":
            toReturn.put("using", "css selector");
            toReturn.put("value", "*[name='" + value + "']");
            break;

          case "partial link text":
            // Do nothing
            break;

          case "tag name":
            toReturn.put("using", "css selector");
            toReturn.put("value", cssEscape(value));
            break;

          case "xpath":
            // Do nothing
            break;
        }
        return toReturn;

Snapshot :

Now, your question must be why this change in the W3C Specs and in the clients. As per #1042 the Answer from the WebDriver Contributors was pretty straight as :

This keeps the specification simple as these can be implemented using the CSS selector, which maps down to querySelector/querySelectorAll.