Showing posts with label xpath. Show all posts
Showing posts with label xpath. Show all posts

13 January 2014

web development notes

WARNING!
This is personal notes for personal and my friends only:
http://dominiksymonowicz.blogspot.co.uk/2014/01/itnotes-information.html
You can read them,but I suggest look to link,resources only


It contains  all information about HTML,CSS and JavaScript (and their framework).



HTML

HTML notes:





CSS
CSS notes:
JavaScript
JavaScript notes:

  • Javascript scope
    • "The second important feature is that functions provide scope. In JavaScript there’s no  curly braces local scope; in other words, blocks don’t create scope. There’s only function scope. Any variable defined with var inside of a function is a local variable, invisible outside the function. Saying that curly braces don’t provide local scope means that if you define a variable with var inside of an if condition or inside of a for or a while loop, that doesn’t mean the variable is local to that if or for. It’s only local to the wrapping function, and if there’s no wrapping function, it becomes a global variable. minimizing the number of globals is a good habit, so functions are indispensable when it comes to keeping the variable scope under control." (find resource!)

JavaScript resources:
  • http://reference.sitepoint.com/javascript/domcore
XPath

Definition:
XPath is a language for finding information in an XML document.
XPath is used to navigate through elements and attributes in an XML document.


Basics:

  • XPath, there are seven kinds of nodes:
  1. attribute,
  2. comment,
  3. document nodes
  4. element,
  5. namespace,
  6. processing-instruction, 
  7. text 
  • XML documents are trees of nodes.
  • Items are atomic values or nodes.
  • Atomic values are nodes with no children or parent.
  • Each element and attribute has one parent. Element nodes may have zero, one or more children.
  • Nodes that have the same parent.
  • Ancestors A node's parent, parent's parent, Descendants A node's children, children's children,
  • XPath uses path expressions to select nodes or node-sets in an XML document.
  • Predicates are used to find a specific node or a node that contains a specific value.
  • XPath wildcards can be used to select unknown XML elements.
  • By using the | operator in an XPath expression you can select several paths.
  • An axis defines a node-set relative to the current node.
  • A location path can be absolute or relative.An absolute location path starts with a slash ( / ) and a relative location path does not.
  • An XPath expression returns either a node-set, a string, a Boolean, or a number.
  • XQuery is used to querying XML data.
  • XSLT is the style sheet language for XML files.

SOLUTIONS FOR COMMON PROBLEMS:

  • Note: In IE 5,6,7,8,9 first node is[0], but according to W3C, it is [1]. To solve this problem in IE, set the SelectionLanguage to XPath.
  •  How to prevent uneven linespacing  when subscripts or superscripts are used  on web pages.
Resources:


Misc. informations:
  • w3schools is quite famous website that provide web development learning content ,but there are many professionals who hats this page and they are even pages about it like http://www.w3fools.com .I am unable to jurge this,but it is worth to mention as it r