JQuery Sizzle entry [Source Code Analysis], jquerysizzle

JQuery Sizzle entry [Source Code Analysis], jquerysizzle

Var Sizzle = function (selector, context, results, seed) {// The default context is document. You can manually specify results = results | []; context = context | document; var origContext = context; // judge if (context. nodeType! = 1 & context. nodeType! = 9) {return [];} // whether the expression is a string if (! Selector | typeof selector! = "String") {return results;} // set: Seed set // checkSet: Copy of seed set // extra: Save the remaining parallel expression, note: The parallel expression // ret is returned. The data type is json, which contains the set and expr attributes. set is the seed set, and expr is the remaining block expression. // cur: the link character of the block expression is as follows: +> ~ If not, the default value is space "" // pop: The last variable of the pop-up array // parts: stores the currently split block expression array var m, set, checkSet, extra, ret, cur, pop, I, prune = true, contextXML = Sizzle. isXML (context), parts = [], soFar = selector; // Reset the position of the chunker regexp (start from head) // you can specify a parallel expression, the end is now. Save the remaining parallel expressions in extra. // For example, # info. p, div. red> ado export chunker.exe c (""); m = chunker.exe c (soFar); if (m) {soFar = m [3]; parts. push (m [1]);/ /Based on the preceding chunker regular expression, if there is a parallel expression, the value of m [2] After exec is "," if (m [2]) {// m [3] is the remaining parallel expression extra = m [3]; break ;}}while (m); // It will be cut as follows: // parts ["# info ",". p "], extra: div. red> a // determine whether there is a location pseudo class origPOS, such as: frist,: last, etc. if there is a location pseudo class, search from left to right for if (parts. length> 1 & origPOS.exe c (selector) {if (parts. length = 2 & Expr. relative [parts [0]) {set = posProcess (parts [0] + parts [1], context, seed);} else {set = Expr. Relative [parts [0]? [Context]: Sizzle (parts. shift (), context); while (parts. length) {selector = parts. shift (); if (Expr. relative [selector]) {selector + = parts. shift () ;}set = posProcess (selector, set, seed );}}} else {// Take a shortcut cut and set the context if the root selector is an ID // (but not if it'll be faster if the inner selector is an ID) // here we mainly modify the context. If the expression starts with the ID type and the last expression is not the ID type, // all the queries, use sizzle. se Lector. find has only the last node, and other nodes can adopt the relationship to determine // The reason why only the first node is id can modify the context, and the last node cannot be ID, because getElementById only exists in the document // This method does not exist in the element. If the last element is ID, an error is reported. // then, the context is changed to the node where the ID is located, to improve efficiency // For example: $ ("# info. p "); then the automatic modification is as follows: $ (". p ", $ (" # info "); if (! Seed & parts. length> 1 & context. nodeType = 9 &&! ContextXML & Expr. match. ID. test (parts [0]) &! Expr. match. ID. test (parts [parts. length-1]) {// call the find method to query the first element in parts and return a temporary result. // if the preceding # info. p will be directly queried # info, and the returned result ret = Sizzle. find (parts. shift (), context, contextXML); // modify contextcontext = ret. expr? Sizzle. filter (ret. expr, ret. set) [0]: ret. set [0];} if (context) {// because the search is performed from right to left, obtain the last element of the array and call parts. pop (); // call the find method to query ret = seed? {Expr: parts. pop (), set: makeArray (seed)}: Sizzle. find (parts. pop (), parts. length = 1 & (parts [0] = "~ "| Parts [0] ===" + ") & context. parentNode? Context. parentNode: context, contextXML); // filter the result set = ret. expr? Sizzle. filter (ret. expr, ret. set): ret. set; if (parts. length> 0) {checkSet = makeArray (set);} else {prune = false;} // continue to the left part of the last element in the block expression. If yes, call link regular expression judgment // such as 1. div. red> p, so p has already been queried. Now the element in parts is ['div. red', '>']; // 2. div. red p, and p has been queried above. Now the element in parts is ['div. red']; while (parts. length) {// retrieve the last element, that is, '>'. If this is the second case, it is 'div. red 'cur = parts. pop (); pop = cur; // whether there is a link symbol. if it is a space, if (! Expr. relative [cur]) {// query whether the cur type exists. For example, in the second case, assign the cur value to "", and then the pop value is div. redcur = "";} else {// retrieve the upper-level element. In the first case, you need to retrieve the last element, which is div. redpop = parts. pop () ;}// if pop is empty, then the default value is entif (pop = null) {pop = context ;}// call the link regular expression judgment, pop is the expression of the element on the left, checkSet is the element to be filtered, and cur is the relational character. // one point to emphasize here is that some people will find that it is called directly and there is no return value, // how can the filtered results be returned? // Here, the javascript function is used to pass values to the array. Modify the checkSet value in the called function. // use the checkSet value later, will also change Expr. relative [cur] (checkSet, pop, contextXML) ;}} else {checkSet = parts = [] ;}} if (! CheckSet) {checkSet = set;} if (! CheckSet) {Sizzle. error (cur | selector);} if (toString. call (checkSet) = "[object Array]") {if (! Prune) {results. push. apply (results, checkSet);} else if (context & context. nodeType = 1) {for (I = 0; checkSet [I]! = Null; I ++) {if (checkSet [I] & (checkSet [I] = true | checkSet [I]. nodeType = 1 & Sizzle. contains (context, checkSet [I]) {results. push (set [I]) ;}} else {for (I = 0; checkSet [I]! = Null; I ++) {if (checkSet [I] & checkSet [I]. nodeType = 1) {results. push (set [I]) ;}}} else {makeArray (checkSet, results);} if (extra) {// a parallel expression exists and Sizzle (extra, origContext, results, seed); // sort the results to remove duplicates and merge the Sizzle. uniqueSort (results);} return results ;};

Jquery source code analysis

The understanding of objects and prototypes will be very helpful.
But it is better to look at the source code after getting familiar with jquery, which will be helpful for understanding and easy to understand.

It is better to look at $. fn. init from the core of jquery and then look at other $. extend.

JQuery Source Code cannot be understood. Why is there a book explaining jQuery source code?

I don't know if there are any books, but there are some source code analysis articles on the Internet. I recommend one for you:
Www.cnblogs.com/..3.html