src/core/init.js

   1 // Initialize a jQuery object
   2 import jQuery from "../core.js";
   3 import document from "../var/document.js";
   4 import rsingleTag from "./var/rsingleTag.js";
   5 import isObviousHtml from "./isObviousHtml.js";
   6
   7 import "../traversing/findFilter.js";
   8
   9 // A central reference to the root jQuery(document)
  10 var rootjQuery,
  11
  12         // A simple way to check for HTML strings
  13         // Prioritize #id over <tag> to avoid XSS via location.hash (#9521)
  14         // Strict HTML recognition (#11290: must start with <)
  15         // Shortcut simple #id case for speed
  16         rquickExpr = /^(?:\s*(<[\w\W]+>)[^>]*|#([\w-]+))$/,
  17
  18         init = jQuery.fn.init = function( selector, context, root ) {
  19                 var match, elem;
  20
  21                 // HANDLE: $(""), $(null), $(undefined), $(false)
  22                 if ( !selector ) {
  23                         return this;
  24                 }
  25
  26                 // Method init() accepts an alternate rootjQuery
  27                 // so migrate can support jQuery.sub (gh-2101)
  28                 root = root || rootjQuery;
  29
  30                 // HANDLE: $(DOMElement)
  31                 if ( selector.nodeType ) {
  32                         this[ 0 ] = selector;
  33                         this.length = 1;
  34                         return this;
  35
  36                 // HANDLE: $(function)
  37                 // Shortcut for document ready
  38                 } else if ( typeof selector === "function" ) {
  39                         return root.ready !== undefined ?
  40                                 root.ready( selector ) :
  41
  42                                 // Execute immediately if ready is not present
  43                                 selector( jQuery );
  44
  45                 } else {
  46
  47                         // Handle obvious HTML strings
  48                         match = selector + "";
  49                         if ( isObviousHtml( match ) ) {
  50
  51                                 // Assume that strings that start and end with <> are HTML and skip
  52                                 // the regex check. This also handles browser-supported HTML wrappers
  53                                 // like TrustedHTML.
  54                                 match = [ null, selector, null ];
  55
  56                         // Handle HTML strings or selectors
  57                         } else if ( typeof selector === "string" ) {
  58                                 match = rquickExpr.exec( selector );
  59                         } else {
  60                                 return jQuery.makeArray( selector, this );
  61                         }
  62
  63                         // Match html or make sure no context is specified for #id
  64                         // Note: match[1] may be a string or a TrustedHTML wrapper
  65                         if ( match && ( match[ 1 ] || !context ) ) {
  66
  67                                 // HANDLE: $(html) -> $(array)
  68                                 if ( match[ 1 ] ) {
  69                                         context = context instanceof jQuery ? context[ 0 ] : context;
  70
  71                                         // Option to run scripts is true for back-compat
  72                                         // Intentionally let the error be thrown if parseHTML is not present
  73                                         jQuery.merge( this, jQuery.parseHTML(
  74                                                 match[ 1 ],
  75                                                 context && context.nodeType ? context.ownerDocument || context : document,
  76                                                 true
  77                                         ) );
  78
  79                                         // HANDLE: $(html, props)
  80                                         if ( rsingleTag.test( match[ 1 ] ) && jQuery.isPlainObject( context ) ) {
  81                                                 for ( match in context ) {
  82
  83                                                         // Properties of context are called as methods if possible
  84                                                         if ( typeof this[ match ] === "function" ) {
  85                                                                 this[ match ]( context[ match ] );
  86
  87                                                         // ...and otherwise set as attributes
  88                                                         } else {
  89                                                                 this.attr( match, context[ match ] );
  90                                                         }
  91                                                 }
  92                                         }
  93
  94                                         return this;
  95
  96                                 // HANDLE: $(#id)
  97                                 } else {
  98                                         elem = document.getElementById( match[ 2 ] );
  99
 100                                         if ( elem ) {
 101
 102                                                 // Inject the element directly into the jQuery object
 103                                                 this[ 0 ] = elem;
 104                                                 this.length = 1;
 105                                         }
 106                                         return this;
 107                                 }
 108
 109                         // HANDLE: $(expr) & $(expr, $(...))
 110                         } else if ( !context || context.jquery ) {
 111                                 return ( context || root ).find( selector );
 112
 113                         // HANDLE: $(expr, context)
 114                         // (which is just equivalent to: $(context).find(expr)
 115                         } else {
 116                                 return this.constructor( context ).find( selector );
 117                         }
 118                 }
 119
 120         };
 121
 122 // Give the init function the jQuery prototype for later instantiation
 123 init.prototype = jQuery.fn;
 124
 125 // Initialize central reference
 126 rootjQuery = jQuery( document );