突出显示文档中的文本得到重复添加

Question

我是angular js 的新手。在这里，我有一个字符串

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged

现在，我在这里尝试突出显示文档中的文本现在，问题就像 ->

在本文中，我通过添加一些 span class 突出显示了 Lorem Ipsum。现在，对于下一次交互，如果 startoffset 和 endoffset 有一个字符串，那只不过是 Ipsum 一直是行业标准。现在， Here 会有这两个重叠，然后突出显示是重叠的。因此，我无法获得确切的文本，因为偏移量发生了变化。

现在，为此我尝试了以下解决方案 ->

const str = 'Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged';

const highlights = [{startOffset: 2, endOffset: 16}, {startOffset: 68, endOffset: 75}, {startOffset: 80, endOffset: 92}];

const result = [];
let currentIndex = 0;

highlights.forEach(h => {
  result.push(str.substring(currentIndex, h.startOffset));
  result.push(`<span class="mark">${str.substring(h.startOffset, h.endOffset)}</span>`);
  currentIndex = h.endOffset;
});

result.push(str.substring(currentIndex, str.length));

document.getElementById('root').innerHTML = result.join('')

现在，在这，它正在解决我的问题，但是如果它重叠，那么在我的字符串中添加了一个重复的文本。如果有一个文本相互重叠，那么它就是分隔文本。但我不想要那种行为。有人能帮我吗？

Answer 1

我不确定我是否正确理解了您的问题，但是如果突出显示的区域像这样重叠，就会出现您的问题？

var highlights = [{startOffset: 2, endOffset: 16}, 
                  {startOffset: 85, endOffset: 100}, 
                  {startOffset: 80, endOffset: 92}];

为此，您必须首先生成不同的区域。

highlights.sort(function (a, b) {return a.startOffset - b.startOffset; }); //first order by the start offset
// highlights looks like this
//[{startOffset: 2, endOffset: 16},
// {startOffset: 80, endOffset: 92},
// {startOffset: 85, endOffset: 100}]

// next merge all overlapping areas

for(var i = 0; i < highlights.length - 1; i++) { //each element but the last, because it can't overlap with the next
    if(highlights[i].endOffset > highlights[i + 1].startOffset) { //if it overlaps with the next
        highlights[i].endOffset = highlights[i].endOffset > highlights[i + 1].endOffset ? 
            highlights[i].endOffset : highlights[i + 1].endOffset; //take the higher end offset of those two as new offset

        highlights.splice(i + 1, 1); //remove next element in list, since it is no longer useful
        i--; //check current element again
    }
}
//output
//[{startOffset: 2, endOffset: 16},
// {startOffset: 80, endOffset: 100}]

之后，您的代码应该可以工作了。