Selenium find element Notes

8 locations for selecting object: (Firebug and firepath for visualising)

by.id:
id attribute is availble, value must be unique, should be constant(not dynamic),

name:
name attribute is availble, value must be unique, should be constant,

classname:
attribute is availble, value must be unique, should be constant, no space(compound name)-if space use only any one word

linktext:
must be a link, must have text, unique

paritlalinktext:
must be a link, must have text(paritlaltext can be taken)

tagname:
any html tag

cssselector:
rules of css, even if no attributes, use tag+atttrib combination
css rules:
using id selector: tag#id or #id (button#epam)
using class selector: tag.class or .class
********** using attribute selector: tag[att='attvalue'][att='attvalue']
using id,class and attributeselector: tag#id[class='value'] or tag.class[id='value']
using attributrnameselector:  css=tag[attribute], not pseudo class syntax: css=tag:not([attribute])
using innertext: css=tag.contains("inner text") supports link+other elements without text
partial match on attribute values:
^= input[id^='ctri'] starting with ctrl
$= input[id$='_ctri'] ending with _ctrl
*= input[id*='ctri'] containing ctrl
TIP:
Absolute: Starting from html tag
Relative: relative to tag
While going through nested elements use > for child elements + for sibling elements
*:nth-child(number) for the nth child element

Xpath: 
xml path language 
query language, search backward forward, slow, flexible
absolutepath: start with /  ,  [1] index starts from 1, [@attribute='value'], structure changes wont work, lengthy 
relativepath:
starts with // , use attributes rather than index, //*[@attribute='value'] - any element in html document, using index use parent for sure
multiple attributes: //tag[@attribute='value'][@attribute='value']   //tag[@attribute='value' and @attribute='value']  //tag[@attribute='value' or @attribute='value']
using attributes: //tag[@attribute]
//tag[starts-with(@att,'val')] //tag[ends-with(@att,'val')] //tag[contains(@att,'val')] //not works in fire bug
//tag[@*='value'] -any attribute with value
//tag[@text()='unicode value'] -alternative to link text
**********Xpath Axis- locate elements based on relationship with other elements
axiselement:: - axis elements are ancestor, descendant, following(everything after closing of current tag), following-sibling(after current node), preceding(nodes appear before except ancestor ) , preceding-sibling(before current node)