Scenario
I am trying to develop a Javascript text highlight function.
It receives in input a text to search inside, an array of tokens to be searched, a class to wrap the found matches:
var fmk = fmk || {};
fmk.highlight = function (target, tokens, cls) {
var token, re;
if (tokens.length > 0) {
token = tokens.pop();
re = new RegExp(token, "gi");
return this.highlight(
target.replace(re, function (matched) {
return "<span class=\"" + cls + "\">" + matched + "</span>";
}), tokens, cls);
}
else { return target; }
};
It is based on a recursive replace that wraps a <span> tag around the found matches.
JsFiddle demo.
Issues
if there are two tokens, and the latter is a substring of the former then only the latter token will be highligthed. In the jsFiddle example try these tokens: 'ab b'.
if the tokens contains a substring of the wrapper sequence (i.e. <span class="[className]"></span>) and another matching token, then the highlight fails and returns a dirty result. In the jsFiddle example try these tokens: 'red ab'.
Note that single character tokens are admitted in the actual application.
Questions
How to avoid these errors? I figured out these approaches:
To pre-process the tokens, removing the tokens that are substrings of others. Disadvantages: it requires O(n^2) searches in the pre-processing phase in case of n tokens; good matches are cut off.
To pre-process the matches BEFORE applying the wrapper, in order to cut off only the substrings matches. Disadvantages: again, further computation required. Anyway, I don't know where to start from implement this inside the replace callback function.
I think the way to handle this is to loop through all descendants of an element, check if it's a text node, and replace the appropriate content wrapped with a span/class.
var MyApp = {};
MyApp.highlighter = (function () {
"use strict";
var checkAndReplace, func,
id = {
container: "container",
tokens: "tokens",
all: "all",
token: "token",
className: "className",
sensitiveSearch: "sensitiveSearch"
};
checkAndReplace = function (node, tokenArr, classNameAll, sensitiveSearchAll) {
var nodeVal = node.nodeValue, parentNode = node.parentNode,
i, j, curToken, myToken, myClassName, mySensitiveSearch,
finalClassName, finalSensitiveSearch,
foundIndex, begin, matched, end,
textNode, span;
for (i = 0, j = tokenArr.length; i < j; i++) {
curToken = tokenArr[i];
myToken = curToken[id.token];
myClassName = curToken[id.className];
mySensitiveSearch = curToken[id.sensitiveSearch];
finalClassName = (classNameAll ? myClassName + " " + classNameAll : myClassName);
finalSensitiveSearch = (typeof sensitiveSearchAll !== "undefined" ? sensitiveSearchAll : mySensitiveSearch);
if (finalSensitiveSearch) {
foundIndex = nodeVal.indexOf(myToken);
} else {
foundIndex = nodeVal.toLowerCase().indexOf(myToken.toLowerCase());
}
if (foundIndex > -1) {
begin = nodeVal.substring(0, foundIndex);
matched = nodeVal.substr(foundIndex, myToken.length);
end = nodeVal.substring(foundIndex + myToken.length, nodeVal.length);
if (begin) {
textNode = document.createTextNode(begin);
parentNode.insertBefore(textNode, node);
}
span = document.createElement("span");
span.className += finalClassName;
span.appendChild(document.createTextNode(matched));
parentNode.insertBefore(span, node);
if (end) {
textNode = document.createTextNode(end);
parentNode.insertBefore(textNode, node);
}
parentNode.removeChild(node);
}
}
};
func = function (options) {
var iterator,
tokens = options[id.tokens],
allClassName = options[id.all][id.className],
allSensitiveSearch = options[id.all][id.sensitiveSearch];
iterator = function (p) {
var children = Array.prototype.slice.call(p.childNodes),
i, cur;
if (children.length) {
for (i = 0; i < children.length; i++) {
cur = children[i];
if (cur.nodeType === 3) {
checkAndReplace(cur, tokens, allClassName, allSensitiveSearch);
} else if (cur.nodeType === 1) {
iterator(cur);
}
}
}
};
iterator(options[id.container]);
};
return func;
})();
window.onload = function () {
var container = document.getElementById("container");
MyApp.highlighter({
container: container,
all: {
className: "highlighter"
},
tokens: [{
token: "sd",
className: "highlight-sd",
sensitiveSearch: false
}, {
token: "SA",
className: "highlight-SA",
sensitiveSearch: true
}]
});
};
DEMO: http://jsfiddle.net/UWQ6r/1/
I set it up so you can change the values in id so that you can use different keys in the {} passed to highlighter.
The two settings in the all object refer to a class being added no matter what, as well as a case sensitive search override. For each token, you specify the token, class, and whether the match should be case sensitive.
References:
nodeType: https://developer.mozilla.org/en-US/docs/DOM/Node.nodeType
childNodes: https://developer.mozilla.org/en-US/docs/DOM/Node.childNodes
substr: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/String/substr
substring: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/String/substring
insertBefore: https://developer.mozilla.org/en-US/docs/DOM/Node.insertBefore
This seems to work for me:
(line 17 in your JsFiddle demo)
Issue 1: var tokens = [['ab','b'].join("|")];
Issue 2: var tokens = ['<span'.replace(/</g,"<")];
All together, then:
var tokens = [[..my tokens..].sort().join("|").replace(/</g,"<")];
(by the way, I did test tokens such as '"', '"s' or 'span' and they seem to work fine. Also, I'm not sure why .sort() is important here but I left it in since I like to stay close to the original code.)
Related
I'm making my Lua engine on CodeMirror (+ luaparser), I changed the show-hint.js addon code a bit, and I want to make sure that the cursor is created on each "$" character, which will be replaced with a void before inserting into the text. I already have an array of all coordinates for cursors, but I can't find an API anywhere on the Internet to create cursors.
ps. Cursors, I mean, those that are created by the combination "Ctrl + LMB"
pick: function(data, i) {
const completion = data.list[i], self = this;
this.cm.operation(function() {
const txt = completion.text;
const indices = [];
let minuses = 0;
for(let i=0; i<txt.length; i++) { // Find "$"
if (txt[i] === "$") {
indices.push(i-minuses);
minuses++;
}
}
completion.text = completion.text.replace('$', ''); // Remove "$"
if (completion.hint)
completion.hint(self.cm, data, completion);
else
self.cm.replaceRange(getText(completion), completion.from || data.from,
completion.to || data.to, "complete");
CodeMirror.signal(data, "pick", completion);
if(indices.length > 0){
for (const indicesKey in indices) {
// TODO: Creating cursors
// Bad try: self.cm.setCursor(data.from.line, data.from.ch+indices[indicesKey]);
}
}
self.cm.scrollIntoView();
});
if (this.options.closeOnPick) {
this.close();
}
}
code
I have built this function to replace a group of characters in a string by a random value from another list within a function:
function replaceExpr(a) {
var expToReplace = 0
var newSent = a
while (expToReplace == 0) {
if (a.search("zx") == -1) {
expToReplace = 1
} else {
var startPos = a.search("zx");
startPos += 2;
var endPos = a.search("xz");
var b = a.substring(startPos, endPos);
var fn = window[b];
if (typeof fn === "function") var newWord = fn();
final = newSent.replace("zx" + b + "xz", newWord);
newSent = final
a = a.replace("zx" + b + "xz", "")
}
}
return final
}
function appearance() {
var list = [
"attractive",
"fit",
"handsome",
"plain",
"short",
"tall",
"skinny",
"well-built",
"unkempt",
"unattractive"
]
return list[Math.floor(Math.random() * list.length)];
}
function personality() {
var list = [
"aggresive",
"absent-minded",
"cautious",
"detached from the real world",
"easygoing",
"focused",
"honest",
"dishonest",
"polite",
"uncivilized"
]
return list[Math.floor(Math.random() * list.length)];
}
An example :
var a = replaceExpr("Theodor is a zxappearancexz man. He seems rather zxpersonalityxz.")
alert(a)
// Theodor is a unattractive man. He seems rather cautious.
Everything works perfectly with the function but I have an issue related to it. As you can see, there's one grammar mistake : it's written "a unattractive" where it should be "an unattractive".
There's a function I usually use to to fix the a\an issue which is :
var AvsAnSimple = (function (root) {
//by Eamon Nerbonne (from http://home.nerbonne.org/A-vs-An), Apache 2.0 license
// finds if a word needs a "a" or "an" before it
var dict = "2h.#2.a;i;&1.N;*4.a;e;i;o;/9.a;e;h1.o.i;l1./;n1.o.o;r1.e.s1./;01.8;12.1a;01.0;12.8;9;2.31.7;4.5.6.7.8.9.8a;0a.0;1;2;3;4;5;6;7;8;9;11; .22; .–.31; .42; .–.55; .,.h.k.m.62; .k.72; .–.82; .,.92; .–.8;<2.m1.d;o;=1.=1.E;#;A6;A1;A1.S;i1;r1;o.m1;a1;r1; .n1;d1;a1;l1;u1;c1.i1.a1.n;s1;t1;u1;r1;i1;a1;s.t1;h1;l1;e1;t1;e1.s;B2.h2.a1.i1;r1;a.á;o1.r1.d1. ;C3.a1.i1.s1.s.h4.a2.i1.s1;e.o1.i;l1.á;r1.o1.í;u2.i;r1.r1.a;o1.n1.g1.j;D7.a1.o1.q;i2.n1.a1.s;o1.t;u1.a1.l1.c;á1. ;ò;ù;ư;E7;U1;R.b1;o1;l1;i.m1;p1;e1;z.n1;a1;m.s1;p5.a1.c;e;h;o;r;u1.l1;o.w1;i.F11. ;,;.;/;0;1;2;3;4;5;6;71.0.8;9;Ae;B.C.D.F.I2.L.R.K.L.M.N.P.Q.R.S.T.B;C1;M.D;E2.C;I;F1;r.H;I3.A1;T.R1. ;U;J;L3.C;N;P;M;O1. ;P1;..R2.A1. ;S;S;T1;S.U2.,;.;X;Y1;V.c;f1.o.h;σ;G7.e1.r1.n1.e;h1.a3.e;i;o;i1.a1.n1.g;o2.f1. ;t1.t1. ;r1.i1.a;w1.a1.r1.r;ú;Hs. ;&;,;.2;A.I.1;2;3;5;7;B1;P.C;D;F;G;H1;I.I6;C.G.N.P.S1.D;T.K1.9;L;M1;..N;O2. ;V;P;R1;T.S1.F.T;V;e2.i1.r;r1.r1.n;o2.n6;d.e1.s;g.k.o2;l.r1;i1.f;v.u1.r;I3;I2;*.I.n1;d1;e1;p1;e1;n1;d2;e1;n1;c1;i.ê.s1;l1;a1;n1;d1;s.J1.i1.a1.o;Ly. ;,;.;1;2;3;4;8;A3. ;P;X;B;C;D;E2. ;D;F1;T.G;H1.D.I1.R;L;M;N;P;R;S1;m.T;U1. ;V1;C.W1.T;Z;^;a1.o1.i1.g;o1.c1.h1.a1;b.p;u1.s1.h1;o.ộ;M15. ;&;,;.1;A1;.1;S./;1;2;3;4;5;6;7;8;Ai;B.C.D.F.G.J.L.M.N.P.R.S.T.V.W.X.Y.Z.B1;S1;T.C;D;E3.P1;S.W;n;F;G;H;I4. ;5;6;T1;M.K;L;M;N;O1.U;P;Q;R;S;T1;R.U2. ;V;V;X;b1.u1.m;f;h;o2.D1.e.U1;..p1.3;s1.c;Ny. ;+;.1.E.4;7;8;:;A3.A1;F.I;S1.L;B;C;D;E3.A;H;S1. ;F1;U.G;H;I7.C.D1. ;K.L.N.O.S.K;L;M1;M.N2.R;T;P1.O1.V1./1.B;R2;J.T.S1;W.T1;L1.D.U1.S;V;W2.A;O1.H;X;Y3.C1.L;P;U;a1.s1.a1.n;t1.h;v;²;×;O5;N1;E.l1;v.n2;c1.e.e1.i;o1;p.u1;i.P1.h2.i1.a;o2.b2;i.o.i;Q1.i1.n1.g1.x;Rz. ;&;,;.1;J./;1;4;6;A3. ;.;F1;T.B1;R.C;D;E3. ;S1.P;U;F;G;H1.S;I2.A;C1. ;J;K;L1;P.M5;1.2.3.5.6.N;O2.H;T2;A.O.P;Q;R1;F.S4;,...?.T.T;U4;B.M.N.S.V;X;c;f1;M1...h2.A;B;ò;S11. ;&;,;.4.E;M;O;T1..3.B;D;M;1;3;4;5;6;8;9;A3. ;8;S2;E.I.B;C3.A1. ;R2.A.U.T;D;E6. ;5;C3;A.O.R.I1.F.O;U;F3;&.H.O1.S.G1;D.H3.2;3;L;I2. ;S1.O.K2.I.Y.L3;A2. ;.;I1. ;O.M3;A1. ;I.U1.R.N5.A.C3.A.B.C.E.F.O.O5. ;A1.I;E;S1;U.V;P7;A7;A.C.D.M.N.R.S.E1. ;I4;C.D.N.R.L1;O.O.U.Y.Q1. ;R;S1;W.T9.A1. ;C;D;F;I;L;M;S;V;U7.B.L.M.N.P.R.S.V;W1.R;X1.M;h1.i1.g1.a1.o;p1.i1.o1;n.t2.B;i1.c1.i;T4.a2.i2.g1.a.s1.c;v1.e1.s;e1.a1.m1.p;u1.i2.l;r;à;Um..1.N1..1.C;/1.1;11. .21.1;L1.T;M1.N;N4.C1.L;D2. .P.K;R1. .a;b2;a.i.d;g1.l;i1.g.l2;i.y.m;no. ;a1.n.b;c;d;e1;s.f;g;h;i2.d;n;j;k;l;m;n;o;p;q;r;s;t;u;v;w;p;r3;a.e.u1.k;s3. ;h;t1;r.t4.h;n;r;t;x;z;í;W2.P1.:4.A1.F;I2.B;N1.H.O1.V;R1.F1.C2.N.U.i1.k1.i1.E1.l1.i;X7;a.e.h.i.o.u.y.Y3.e1.t1.h;p;s;[5.A;E;I;a;e;_2._1.i;e;`3.a;e;i;a7; .m1;a1;r1. .n1;d2; .ě.p1;r1;t.r1;t1;í.u1;s1;s1;i1. .v1;u1;t.d3.a1.s1. ;e2.m1. ;r1. ;i2.c1.h1. ;e1.s1.e2.m;r;e8;c1;o1;n1;o1;m1;i1;a.e1;w.l1;i1;t1;e1;i.m1;p1;e1;z.n1;t1;e1;n1;d.s2;a1. .t4;a1; .e1; .i1;m1;a1;r.r1;u1.t.u1.p1. ;w.f3. ;M;y1.i;h9. ;,;.;C;a1.u1.t1;b.e2.i1.r1;a.r1.m1.a1.n;o4.m2.a1; .m;n8; .b.d.e3; .d.y.g.i.k.v.r1.s1. ;u1.r;r1. ;t1;t1;p1;:.i6;b1;n.e1;r.n2;f2;l1;u1;ê.o1;a.s1;t1;a1;l1;a.r1; .s1; .u.k1.u1. ;l3.c1.d;s1. ;v1.a;ma. ;,;R;b1.a.e1.i1.n;f;p;t1.a.u1.l1.t1.i1.c1.a1.m1.p1.i;×;n6. ;V;W;d1; .t;×;o8;c2;h1;o.u1;p.d1;d1;y.f1; .g1;g1;i.no. ;';,;/;a;b;c1.o;d;e2.i;r;f;g;i;l;m;n;o;r;s;t;u;w;y;z;–;r1;i1;g1;e.t1;r1.s;u1;i.r3. ;&;f;s9.,;?;R;f2.e.o.i1.c1.h;l1. ;p2.3;i1. ;r1.g;v3.a.e.i.t2.A;S;uc; ...b2.e;l;f.k2.a;i;m1;a1. .n3;a3; .n5.a;c;n;s;t;r1;y.e2; .i.i8.c2.o1.r1.p;u1.m;d1;i1.o;g1.n;l1.l;m1;o.n;s1.s;v1.o1;c.r5;a.e.i.l.o.s3. ;h;u1.r2;e.p3;a.e.i.t2.m;t;v.w1.a;xb. ;';,;.;8;b;k;l;m1;a.t;y1. ;y1.l;{1.a;|1.a;£1.8;À;Á;Ä;Å;Æ;É;Ò;Ó;Ö;Ü;à;á;æ;è;é1;t3.a;o;u;í;ö;ü1; .Ā;ā;ī;İ;Ō;ō;œ;Ω;α;ε;ω;ϵ;е;–2.e;i;ℓ;";
function fill(node) {
var kidCount = parseInt(dict, 36) || 0,
offset = kidCount && kidCount.toString(36).length;
node.article = dict[offset] == "." ? "a" : "an";
dict = dict.substr(1 + offset);
for (var i = 0; i < kidCount; i++) {
var kid = node[dict[0]] = {}
dict = dict.substr(1);
fill(kid);
}
}
fill(root);
return {
raw: root,
//Usage example: AvsAnSimple.query("example")
//example returns: "an"
query: function (word) {
var node = root, sI = 0, result, c;
do {
c = word[sI++];
} while ('"‘’“”$\''.indexOf(c) >= 0);//also terminates on end-of-string "undefined".
while (1) {
result = node.article || result;
node = node[c];
if (!node) return result;
c = word[sI++] || " ";
}
}
};
})({})
Now, the problem is that I can't find a way to use this function in conjunction with the replaceExpr. The following obviously wouldn't work because of order precedence :
var a = replaceExpr("Theodor is " + AvsAnSimple(zxappearancexz) + "man. He seems rather " + AvsAnSimple(zxpersonalityxz).")
I just recently started learning javascript so my knowledge is rather limited. Any ideas how I could overcome this?
Thank you!
You could use a regular expression to optionally match the " a " or "an" before your word in the input string and store that matched portion in a variable using the String.match() function, then check if that " a " or " an " exists in your matched string, do the manipulations you need to do and store that manipulated string in a separate variable, then use String.replace() to find that previously matched string again, and replace it wit
your manipulated string. The regular expression you could use for this is /(\san?\s)?(zx\w*zx)/gm
See the regular expression here for more context.
Thank you Joseph! With your help I managed to find something that works by using your regular expression. Here's my function :
function replaceExpr(a) {
var nbExprToReplace = 1;
while (nbExprToReplace == 1) {
if (a.search("zx") == -1) {
nbExprToReplace = 0;
} else {
var currentGroup = a.match(/(\san?\s)?(zx\w*xz)/);
var exprToChange = currentGroup[2];
exprToChange = exprToChange.slice(2,-2);
var exprToChange = window[exprToChange];
if (typeof exprToChange !== "function") {
alert("the keyword is not a recognized function!");
break;
} else {
exprToChange = exprToChange();
var final = exprToChange
};
if (currentGroup[1] === undefined) {
} else {
var newArticle = AvsAnSimple.query(exprToChange);
final = newArticle.concat(" " + final)
};
a = a.replace(currentGroup[0], " " + final);
};
};
return a;
};
I'm trying to write a simple function that iterates through text and replaces any href's it comes across with text instead;
var REPLACE = [
{expression: www.anyhref.com, value: 'website'}
];
function(instance) {
instance = function {
var insteadURL;
insteadURL: = REPLACE.match(function(expression) {
return element.classList.contains(expression);
});
return(
insteadURL ? insteadURL.value : getElementText(expression)
);
}
}
I feel as though I may not be using the match method or the conditional operator properly but from what I understand this should work. But of course it doesn't.
If you're trying to replace links (i guess) in your text, try this regex:
/<a.*?href="www.anyhref.com".*?\/a>/g
Then you would have to add for each href you want to replace an entry in your array.
If you are in DOM context you can do the following:
To iterate through the DOM you can use this function:
function domReplace(node, iterator) {
switch (node && node.nodeType) {
case 1: case 9: case 11: {
const newNode = iterator((node.nodeName || '').toLowerCase(), node);
if (newNode && newNode != node && node.parentNode) {
node.parentNode.insertBefore(newNode, node);
node.parentNode.removeChild(node);
}
for (let child = newNode.firstChild; child; child = child.nextSibling)
domReplace(child, iterator);
} break ;
case 3: {
const newNode = iterator('#text', node);
if (newNode && newNode != node && node.parentNode) {
node.parentNode.insertBefore(newNode, node);
node.parentNode.removeChild(node);
}
} break ;
}
}
Then you can replace a if pattern matches .href with custom text:
domReplace(document, (type, node) => {
if (type == 'a') {
for (let i = 0; i < REPLACE.length; i += 1)
if (~(node.href || '').indexOf(REPLACE[i].expression))
return document.createTextNode(REPLACE[i].value);
return document.createTextNode(node.href);
}
return node;
});
Note you should not give document to domReplace but the right dom node to avoid full page replacement
I have the following function that is supposed to get all elements in a document with the given class:
function getElementByClass(objClass)
{
// This function is similar to 'getElementByID' since there is no inherent function to get an element by it's class
var elements = (ie) ? document.all : document.getElementsByTagName('*');
for (i=0; i<elements.length; i++)
{
alert(elements[i].className);
alert(objClass);
if (elements[i].className==objClass)
{
return elements[i]
}
}
}
When I call this function with:
<script type="text/javascript">document.write(getElementByClass('done'));</script>
Nothing happens. Is there something wrong with the function?
This function does not get all elements with that class name, it gets one. And what is your intent with the way you are calling it? document.write seems like a funny thing to do with a DOM element already on your page.
I hate to just say "use jquery"... but you probably should.
Aside from the missing declaration of ie, this function does work. One problem you will have with it is if you have multiple classes on an element, this function won't work.
document.getElementsByClassName('done');
EDIT:
src: http://robertnyman.com/2008/05/27/the-ultimate-getelementsbyclassname-anno-2008/
/*
Developed by Robert Nyman, http://www.robertnyman.com
Code/licensing: http://code.google.com/p/getelementsbyclassname/
*/
var getElementsByClassName = function (className, tag, elm){
if (document.getElementsByClassName) {
getElementsByClassName = function (className, tag, elm) {
elm = elm || document;
var elements = elm.getElementsByClassName(className),
nodeName = (tag)? new RegExp("\\b" + tag + "\\b", "i") : null,
returnElements = [],
current;
for(var i=0, il=elements.length; i<il; i+=1){
current = elements[i];
if(!nodeName || nodeName.test(current.nodeName)) {
returnElements.push(current);
}
}
return returnElements;
};
}
else if (document.evaluate) {
getElementsByClassName = function (className, tag, elm) {
tag = tag || "*";
elm = elm || document;
var classes = className.split(" "),
classesToCheck = "",
xhtmlNamespace = "http://www.w3.org/1999/xhtml",
namespaceResolver = (document.documentElement.namespaceURI === xhtmlNamespace)? xhtmlNamespace : null,
returnElements = [],
elements,
node;
for(var j=0, jl=classes.length; j<jl; j+=1){
classesToCheck += "[contains(concat(' ', #class, ' '), ' " + classes[j] + " ')]";
}
try {
elements = document.evaluate(".//" + tag + classesToCheck, elm, namespaceResolver, 0, null);
}
catch (e) {
elements = document.evaluate(".//" + tag + classesToCheck, elm, null, 0, null);
}
while ((node = elements.iterateNext())) {
returnElements.push(node);
}
return returnElements;
};
}
else {
getElementsByClassName = function (className, tag, elm) {
tag = tag || "*";
elm = elm || document;
var classes = className.split(" "),
classesToCheck = [],
elements = (tag === "*" && elm.all)? elm.all : elm.getElementsByTagName(tag),
current,
returnElements = [],
match;
for(var k=0, kl=classes.length; k<kl; k+=1){
classesToCheck.push(new RegExp("(^|\\s)" + classes[k] + "(\\s|$)"));
}
for(var l=0, ll=elements.length; l<ll; l+=1){
current = elements[l];
match = false;
for(var m=0, ml=classesToCheck.length; m<ml; m+=1){
match = classesToCheck[m].test(current.className);
if (!match) {
break;
}
}
if (match) {
returnElements.push(current);
}
}
return returnElements;
};
}
return getElementsByClassName(className, tag, elm);
};
if you have posted full source then what is ie in
var elements = (ie) ? document.all : document.getElementsByTagName('*');
try to track error via firebug.
var elements = (ie) is referencing an undefined variable ie
Have you considered using a JavaScript library? Functions like this have been written many times before, painful to waste time on these kinds of things.
You should probably use getElementsByClassName when available.
Since element.classList is not supported in IE 9 and Safari-5, what's an alternative cross-browser solution?
No-frameworks please.
Solution must work in at least IE 9, Safari 5, FireFox 4, Opera 11.5, and Chrome.
Related posts (but does not contain solution):
how to add and remove css class
Add and remove a class with animation
Add remove class?
Here is solution for addClass, removeClass, hasClass in pure javascript solution.
Actually it's from http://jaketrent.com/post/addremove-classes-raw-javascript/
function hasClass(ele,cls) {
return !!ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));
}
function addClass(ele,cls) {
if (!hasClass(ele,cls)) ele.className += " "+cls;
}
function removeClass(ele,cls) {
if (hasClass(ele,cls)) {
var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
ele.className=ele.className.replace(reg,' ');
}
}
Look at these oneliners:
Remove class:
element.classList.remove('hidden');
Add class (will not add it twice if already present):
element.classList.add('hidden');
Toggle class (adds the class if it's not already present and removes it if it is)
element.classList.toggle('hidden');
That's all! I made a test - 10000 iterations. 0.8s.
I just wrote these up:
function addClass(el, classNameToAdd){
el.className += ' ' + classNameToAdd;
}
function removeClass(el, classNameToRemove){
var elClass = ' ' + el.className + ' ';
while(elClass.indexOf(' ' + classNameToRemove + ' ') !== -1){
elClass = elClass.replace(' ' + classNameToRemove + ' ', '');
}
el.className = elClass;
}
I think they'll work in all browsers.
The simplest is element.classList which has remove(name), add(name), toggle(name), and contains(name) methods and is now supported by all major browsers.
For older browsers you change element.className. Here are two helper:
function addClass(element, className){
element.className += ' ' + className;
}
function removeClass(element, className) {
element.className = element.className.replace(
new RegExp('( |^)' + className + '( |$)', 'g'), ' ').trim();
}
One way to play around with classes without frameworks/libraries would be using the property Element.className, which "gets and sets the value of the class attribute of the specified element." (from the MDN documentation).
As #matías-fidemraizer already mentioned in his answer, once you get the string of classes for your element you can use any methods associated with strings to modify it.
Here's an example:
Assuming you have a div with the ID "myDiv" and that you want to add to it the class "main__section" when the user clicks on it,
window.onload = init;
function init() {
document.getElementById("myDiv").onclick = addMyClass;
}
function addMyClass() {
var classString = this.className; // returns the string of all the classes for myDiv
var newClass = classString.concat(" main__section"); // Adds the class "main__section" to the string (notice the leading space)
this.className = newClass; // sets className to the new string
}
Read this Mozilla Developer Network article:
https://developer.mozilla.org/en/DOM/element.className
Since element.className property is of type string, you can use regular String object functions found in any JavaScript implementation:
If you want to add a class, first use String.indexOf in order to check if class is present in className. If it's not present, just concatenate a blank character and the new class name to this property. If it's present, do nothing.
If you want to remove a class, just use String.replace, replacing "[className]" with an empty string. Finally use String.trim to remove blank characters at the start and end of element.className.
Fixed the solution from #Paulpro
Do not use "class", as it is a reserved word
removeClass function
was broken, as it bugged out after repeated use.
`
function addClass(el, newClassName){
el.className += ' ' + newClassName;
}
function removeClass(el, removeClassName){
var elClass = el.className;
while(elClass.indexOf(removeClassName) != -1) {
elClass = elClass.replace(removeClassName, '');
elClass = elClass.trim();
}
el.className = elClass;
}
The solution is to
Shim .classList:
Either use the DOM-shim or use Eli Grey's shim below
Disclaimer: I believe the support is FF3.6+, Opera10+, FF5, Chrome, IE8+
/*
* classList.js: Cross-browser full element.classList implementation.
* 2011-06-15
*
* By Eli Grey, http://eligrey.com
* Public Domain.
* NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
*/
/*global self, document, DOMException */
/*! #source http://purl.eligrey.com/github/classList.js/blob/master/classList.js*/
if (typeof document !== "undefined" && !("classList" in document.createElement("a"))) {
(function (view) {
"use strict";
var
classListProp = "classList"
, protoProp = "prototype"
, elemCtrProto = (view.HTMLElement || view.Element)[protoProp]
, objCtr = Object
, strTrim = String[protoProp].trim || function () {
return this.replace(/^\s+|\s+$/g, "");
}
, arrIndexOf = Array[protoProp].indexOf || function (item) {
var
i = 0
, len = this.length
;
for (; i < len; i++) {
if (i in this && this[i] === item) {
return i;
}
}
return -1;
}
// Vendors: please allow content code to instantiate DOMExceptions
, DOMEx = function (type, message) {
this.name = type;
this.code = DOMException[type];
this.message = message;
}
, checkTokenAndGetIndex = function (classList, token) {
if (token === "") {
throw new DOMEx(
"SYNTAX_ERR"
, "An invalid or illegal string was specified"
);
}
if (/\s/.test(token)) {
throw new DOMEx(
"INVALID_CHARACTER_ERR"
, "String contains an invalid character"
);
}
return arrIndexOf.call(classList, token);
}
, ClassList = function (elem) {
var
trimmedClasses = strTrim.call(elem.className)
, classes = trimmedClasses ? trimmedClasses.split(/\s+/) : []
, i = 0
, len = classes.length
;
for (; i < len; i++) {
this.push(classes[i]);
}
this._updateClassName = function () {
elem.className = this.toString();
};
}
, classListProto = ClassList[protoProp] = []
, classListGetter = function () {
return new ClassList(this);
}
;
// Most DOMException implementations don't allow calling DOMException's toString()
// on non-DOMExceptions. Error's toString() is sufficient here.
DOMEx[protoProp] = Error[protoProp];
classListProto.item = function (i) {
return this[i] || null;
};
classListProto.contains = function (token) {
token += "";
return checkTokenAndGetIndex(this, token) !== -1;
};
classListProto.add = function (token) {
token += "";
if (checkTokenAndGetIndex(this, token) === -1) {
this.push(token);
this._updateClassName();
}
};
classListProto.remove = function (token) {
token += "";
var index = checkTokenAndGetIndex(this, token);
if (index !== -1) {
this.splice(index, 1);
this._updateClassName();
}
};
classListProto.toggle = function (token) {
token += "";
if (checkTokenAndGetIndex(this, token) === -1) {
this.add(token);
} else {
this.remove(token);
}
};
classListProto.toString = function () {
return this.join(" ");
};
if (objCtr.defineProperty) {
var classListPropDesc = {
get: classListGetter
, enumerable: true
, configurable: true
};
try {
objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
} catch (ex) { // IE 8 doesn't support enumerable:true
if (ex.number === -0x7FF5EC54) {
classListPropDesc.enumerable = false;
objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
}
}
} else if (objCtr[protoProp].__defineGetter__) {
elemCtrProto.__defineGetter__(classListProp, classListGetter);
}
}(self));
}
Improved version of emil's code (with trim())
function hasClass(ele,cls) {
return !!ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));
}
function addClass(ele,cls) {
if (!hasClass(ele,cls)) ele.className = ele.className.trim() + " " + cls;
}
function removeClass(ele,cls) {
if (hasClass(ele,cls)) {
var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
ele.className = ele.className.replace(reg,' ');
ele.className = ele.className.trim();
}
}
function addClass(element, classString) {
element.className = element
.className
.split(' ')
.filter(function (name) { return name !== classString; })
.concat(classString)
.join(' ');
}
function removeClass(element, classString) {
element.className = element
.className
.split(' ')
.filter(function (name) { return name !== classString; })
.join(' ');
}
Just in case if anyone would like to have prototype functions built for elements, this is what I use when I need to manipulate classes of different objects:
Element.prototype.addClass = function (classToAdd) {
var classes = this.className.split(' ')
if (classes.indexOf(classToAdd) === -1) classes.push(classToAdd)
this.className = classes.join(' ')
}
Element.prototype.removeClass = function (classToRemove) {
var classes = this.className.split(' ')
var idx =classes.indexOf(classToRemove)
if (idx !== -1) classes.splice(idx,1)
this.className = classes.join(' ')
}
Use them like:
document.body.addClass('whatever') or document.body.removeClass('whatever')
Instead of body you can also use any other element (div, span, you name it)
add css classes: cssClassesStr += cssClassName;
remove css classes: cssClassStr = cssClassStr.replace(cssClassName,"");
add attribute 'Classes': object.setAttribute("class", ""); //pure addition of this attribute
remove attribute: object.removeAttribute("class");
A easy to understand way:
// Add class
DOMElement.className += " one";
// Example:
// var el = document.body;
// el.className += " two"
// Remove class
function removeDOMClass(element, className) {
var oldClasses = element.className,
oldClassesArray = oldClasses.split(" "),
newClassesArray = [],
newClasses;
// Sort
var currentClassChecked,
i;
for ( i = 0; i < oldClassesArray.length; i++ ) {
// Specified class will not be added in the new array
currentClassChecked = oldClassesArray[i];
if( currentClassChecked !== className ) {
newClassesArray.push(currentClassChecked);
}
}
// Order
newClasses = newClassesArray.join(" ");
// Apply
element.className = newClasses;
return element;
}
// Example:
// var el = document.body;
// removeDOMClass(el, "two")
https://gist.github.com/sorcamarian/ff8db48c4dbf4f5000982072611955a2