js文本差异比较
算法是网上找的算法。。只是自己做了比较的效果
上代码直接
<!doctype html>
<html>
<head>
<title>文本比较工具</title>
<style type="text/css">
.text textarea {
resize: none;
background: none repeat scroll 0 0 transparent;
border: 0 none;
width: 97%;
height: 500px;
overflow-y: scroll;
position: absolute;
left: 0;
top: 0;
z-index: 2;
font-size: 18px;
white-space: pre-wrap;
word-wrap: break-word;
word-break: break-all;
border: 1px solid red;
}
.text {
overflow-y: scroll;
white-space: pre-wrap;
word-wrap: break-word;
word-break: break-all;
width: 50%;
float: left;
text-align: left;
z-index: 1;
font-size: 18px;
position: relative;
min-height: 510px;
}
.add {
color: red;
}
.delete {
color: blue;
text-decoration: line-through;
}
.button {
width: 100%;
line-height: 30px;
font-size: 30px;
border: 1px solid green;
padding: 10px;
cursor: pointer;
text-align: center;
}
#result-box {
padding: 20px;
border: 1px solid blue;
}
.compare-box:after{
content: "";
display:block;
clear: both;
}
#result{
font-size: 20px;
}
</style>
</head>
<body>
<div id="result-box">
<pre id="result"></pre>
</div>
<div class="compare-box">
<div class="text left-box">
<textarea id="edit_textarea_1"></textarea>
</div>
<div class="text right-box">
<textarea id="edit_textarea_2"></textarea>
</div>
</div>
<div class="button">比较</div>
<script type="text/javascript">
function textchange() {
var op = eq({ value1: document.getElementById("edit_textarea_1").value, value2: document.getElementById("edit_textarea_2").value });
document.getElementById("result").innerHTML = op.value2 + "\r\n";
}
function eq(op) {
if (!op) {
return op;
}
if (!op.eq_min) {
op.eq_min = 3;
}
if (!op.eq_index) {
op.eq_index = 5;
}
if (!op.value1 || !op.value2) {
return op;
}
var ps = {
v1_i: 0,
v1_new_value: "",
v2_i: 0,
v2_new_value: ""
};
while (ps.v1_i < op.value1.length && ps.v2_i < op.value2.length) {
if (op.value1[ps.v1_i] == op.value2[ps.v2_i]) {
//ps.v1_new_value += op.value1[ps.v1_i].replace(/</g,"<").replace(">",">");
ps.v2_new_value += op.value2[ps.v2_i].replace(/</g, "<").replace(">", ">");
ps.v1_i += 1;
ps.v2_i += 1;
//值2增加的部分
if (ps.v1_i >= op.value1.length) {
ps.v2_new_value += "<span class='add'>" + op.value2.substr(ps.v2_i).replace(/</g, "<").replace(">", ">") + "</span>";
break;
}
//值1删除的部分
if (ps.v2_i >= op.value2.length) {
//ps.v1_new_value += "<span style='" + op.value1_style + "'>值1多的" + op.value1.substr(ps.v1_i).replace(/</g,"<").replace(">",">") + "</span>";
ps.v2_new_value += "<span class='delete'>" + op.value1.substr(ps.v1_i).replace(/</g, "<").replace(">", ">") + "</span>";
break;
}
} else {
ps.v1_index = ps.v1_i + 1;
ps.v1_eq_length = 0;
ps.v1_eq_max = 0;
ps.v1_start = ps.v1_i + 1;
while (ps.v1_index < op.value1.length) {
if (op.value1[ps.v1_index] == op.value2[ps.v2_i + ps.v1_eq_length]) {
ps.v1_eq_length += 1;
} else if (ps.v1_eq_length > 0) {
if (ps.v1_eq_max < ps.v1_eq_length) {
ps.v1_eq_max = ps.v1_eq_length;
ps.v1_start = ps.v1_index - ps.v1_eq_length;
}
ps.v1_eq_length = 0;
break;//只寻找最近的
}
ps.v1_index += 1;
}
if (ps.v1_eq_max < ps.v1_eq_length) {
ps.v1_eq_max = ps.v1_eq_length;
ps.v1_start = ps.v1_index - ps.v1_eq_length;
}
ps.v2_index = ps.v2_i + 1;
ps.v2_eq_length = 0;
ps.v2_eq_max = 0;
ps.v2_start = ps.v2_i + 1;
while (ps.v2_index < op.value2.length) {
if (op.value2[ps.v2_index] == op.value1[ps.v1_i + ps.v2_eq_length]) {
ps.v2_eq_length += 1;
} else if (ps.v2_eq_length > 0) {
if (ps.v2_eq_max < ps.v2_eq_length) {
ps.v2_eq_max = ps.v2_eq_length;
ps.v2_start = ps.v2_index - ps.v2_eq_length;
}
ps.v1_eq_length = 0;
break;//只寻找最近的
}
ps.v2_index += 1;
}
if (ps.v2_eq_max < ps.v2_eq_length) {
ps.v2_eq_max = ps.v2_eq_length;
ps.v2_start = ps.v2_index - ps.v2_eq_length;
}
if (ps.v1_eq_max < op.eq_min && ps.v1_start - ps.v1_i > op.eq_index) {
ps.v1_eq_max = 0;
}
if (ps.v2_eq_max < op.eq_min && ps.v2_start - ps.v2_i > op.eq_index) {
ps.v2_eq_max = 0;
}
if ((ps.v1_eq_max == 0 && ps.v2_eq_max == 0)) {
//两个值的字不同
//ps.v1_new_value += "<span style='" + op.value1_style + "'>不同的" + op.value1[ps.v1_i].replace(/</g,"<").replace(">",">") + "</span>";
ps.v2_new_value += "<span class='delete'>" + op.value1[ps.v1_i].replace(/</g, "<").replace(">", ">") + "</span>";
ps.v2_new_value += "<span class='add'>" + op.value2[ps.v2_i].replace(/</g, "<").replace(">", ">") + "</span>";
ps.v1_i += 1;
ps.v2_i += 1;
if (ps.v1_i >= op.value1.length) {
//值2增加的部分
ps.v2_new_value += "<span class='add'>" + op.value2.substr(ps.v2_i).replace(/</g, "<").replace(">", ">") + "</span>";
break;
}
if (ps.v2_i >= op.value2.length) {
//值1删除的部分
//ps.v1_new_value += "<span style='" + op.value1_style + "'>值1多的" + op.value1.substr(ps.v1_i).replace(/</g,"<").replace(">",">") + "</span>";
ps.v2_new_value += "<span class='delete'>" + op.value1.substr(ps.v1_i).replace(/</g, "<").replace(">", ">") + "</span>";
break;
}
//值1删除的
} else if (ps.v1_eq_max > ps.v2_eq_max) {
//ps.v1_new_value += "<span style='" + op.value1_style + "'>值1删除的" + op.value1.substr(ps.v1_i, ps.v1_start - ps.v1_i).replace(/</g,"<").replace(">",">") + "</span>";
ps.v2_new_value += "<span class='delete'>" + op.value1.substr(ps.v1_i, ps.v1_start - ps.v1_i).replace(/</g, "<").replace(">", ">") + "</span>";
ps.v1_i = ps.v1_start;
} else {
//值2增加的
ps.v2_new_value += "<span class='add'>" + op.value2.substr(ps.v2_i, ps.v2_start - ps.v2_i).replace(/</g, "<").replace(">", ">") + "</span>";
ps.v2_i = ps.v2_start;
}
}
}
op.value1 = ps.v1_new_value;
op.value2 = ps.v2_new_value;
//有多个连着修改的放在一起
var addRule = /<span class='add'>((?!<span).)+<\/span>/g;
var deleteRule = /<span class='delete'>((?!<span).)+<\/span>/g;
var allRule = /(<span class='delete'>((?!<span).)+<\/span><span class='add'>((?!<span).)+<\/span>){2,}/g;
op.value2 = op.value2.replace(allRule, function (str) {
var beforText = "", afterText = "";
var beforeMatch = str.match(deleteRule);
for (var i = 0; i < beforeMatch.length; i++) {
var m = beforeMatch[i].match(deleteRule);
beforText += RegExp.$1;
}
var afterMatch = str.match(addRule);
for (var i = 0; i < afterMatch.length; i++) {
var m = afterMatch[i].match(addRule);
afterText += RegExp.$1;
}
return "<span class='delete'>" + beforText + "</span><span class='add'>" + afterText + "</span>";
});
return op;
}
window.onload = function () {
document.getElementsByClassName("button")[0].addEventListener("click", textchange);
}
</script>
</body>
</html>
