[英]How to insert text into the textarea at the current cursor position?
我想创建一个简单的函数,将文本添加到用户光标位置的文本区域中。 它需要是一个干净的功能。 只是基础知识。 我可以弄清楚其余的。
使用输入元素的selectionStart
/ selectionEnd
属性(也适用于<textarea>
)
function insertAtCursor(myField, myValue) {
//IE support
if (document.selection) {
myField.focus();
sel = document.selection.createRange();
sel.text = myValue;
}
//MOZILLA and others
else if (myField.selectionStart || myField.selectionStart == '0') {
var startPos = myField.selectionStart;
var endPos = myField.selectionEnd;
myField.value = myField.value.substring(0, startPos)
+ myValue
+ myField.value.substring(endPos, myField.value.length);
} else {
myField.value += myValue;
}
}
这个片段可以在几行 jQuery 1.9+ 中帮助你:http: //jsfiddle.net/4MBUG/2/
$('input[type=button]').on('click', function() {
var cursorPos = $('#text').prop('selectionStart');
var v = $('#text').val();
var textBefore = v.substring(0, cursorPos);
var textAfter = v.substring(cursorPos, v.length);
$('#text').val(textBefore + $(this).val() + textAfter);
});
https://developer.mozilla.org/en-US/docs/Web/API/HTMLInputElement/setRangeText
我不确定浏览器对此的支持。
在 Chrome 81 中测试。
function typeInTextarea(newText, el = document.activeElement) { const [start, end] = [el.selectionStart, el.selectionEnd]; el.setRangeText(newText, start, end, 'select'); } document.getElementById("input").onkeydown = e => { if (e.key === "Enter") typeInTextarea("lol"); }
<input id="input" /> <br/><br/> <div>Press Enter to insert "lol" at caret.</div> <div>It'll replace a selection with the given text.</div>
Erik Pukinskis 回答的纯 JS 修改:
function typeInTextarea(newText, el = document.activeElement) { const start = el.selectionStart const end = el.selectionEnd const text = el.value const before = text.substring(0, start) const after = text.substring(end, text.length) el.value = (before + newText + after) el.selectionStart = el.selectionEnd = start + newText.length el.focus() } document.getElementById("input").onkeydown = e => { if (e.key === "Enter") typeInTextarea("lol"); }
<input id="input" /> <br/><br/> <div>Press Enter to insert "lol" at caret.</div>
在 Chrome 47、81 和 Firefox 76 中测试。
如果您想在输入同一字段时更改当前选定文本的值(用于自动完成或类似效果),请将document.activeElement
作为第一个参数传递。
这不是最优雅的方法,但它非常简单。
示例用法:
typeInTextarea('hello');
typeInTextarea('haha', document.getElementById('some-id'));
为了正确的Javascript
HTMLTextAreaElement.prototype.insertAtCaret = function (text) {
text = text || '';
if (document.selection) {
// IE
this.focus();
var sel = document.selection.createRange();
sel.text = text;
} else if (this.selectionStart || this.selectionStart === 0) {
// Others
var startPos = this.selectionStart;
var endPos = this.selectionEnd;
this.value = this.value.substring(0, startPos) +
text +
this.value.substring(endPos, this.value.length);
this.selectionStart = startPos + text.length;
this.selectionEnd = startPos + text.length;
} else {
this.value += text;
}
};
一个简单的解决方案,适用于 firefox、chrome、opera、safari 和 edge,但可能不适用于旧的 IE 浏览器。
var target = document.getElementById("mytextarea_id")
if (target.setRangeText) {
//if setRangeText function is supported by current browser
target.setRangeText(data)
} else {
target.focus()
document.execCommand('insertText', false /*no UI*/, data);
}
setRangeText
函数允许您用提供的文本替换当前选择,或者如果没有选择,则在光标位置插入文本。 据我所知,它仅受 Firefox 支持。
对于其他浏览器,“insertText”命令仅影响当前聚焦的 html 元素,并且具有与setRangeText
相同的行为
部分灵感来自这篇文章
我喜欢简单的javascript ,而且我通常有jQuery 。 这是我根据mparkuk 提出的:
function typeInTextarea(el, newText) {
var start = el.prop("selectionStart")
var end = el.prop("selectionEnd")
var text = el.val()
var before = text.substring(0, start)
var after = text.substring(end, text.length)
el.val(before + newText + after)
el[0].selectionStart = el[0].selectionEnd = start + newText.length
el.focus()
}
$("button").on("click", function() {
typeInTextarea($("textarea"), "some text")
return false
})
这是一个演示: http ://codepen.io/erikpukinskis/pen/EjaaMY?editors=101
Rab 的回答效果很好,但不适用于 Microsoft Edge,所以我也为 Edge 添加了一个小的改编:
https://jsfiddle.net/et9borp4/
function insertAtCursor(myField, myValue) {
//IE support
if (document.selection) {
myField.focus();
sel = document.selection.createRange();
sel.text = myValue;
}
// Microsoft Edge
else if(window.navigator.userAgent.indexOf("Edge") > -1) {
var startPos = myField.selectionStart;
var endPos = myField.selectionEnd;
myField.value = myField.value.substring(0, startPos)+ myValue
+ myField.value.substring(endPos, myField.value.length);
var pos = startPos + myValue.length;
myField.focus();
myField.setSelectionRange(pos, pos);
}
//MOZILLA and others
else if (myField.selectionStart || myField.selectionStart == '0') {
var startPos = myField.selectionStart;
var endPos = myField.selectionEnd;
myField.value = myField.value.substring(0, startPos)
+ myValue
+ myField.value.substring(endPos, myField.value.length);
} else {
myField.value += myValue;
}
}
如果用户在插入文本后没有触摸输入,则永远不会触发 'input' 事件,并且 value 属性不会反映更改。 因此,在以编程方式插入文本后触发输入事件很重要。 聚焦领域是不够的。
以下是Snorvarg 的答案副本,最后带有输入触发器:
function insertAtCursor(myField, myValue) {
//IE support
if (document.selection) {
myField.focus();
sel = document.selection.createRange();
sel.text = myValue;
}
// Microsoft Edge
else if(window.navigator.userAgent.indexOf("Edge") > -1) {
var startPos = myField.selectionStart;
var endPos = myField.selectionEnd;
myField.value = myField.value.substring(0, startPos)+ myValue
+ myField.value.substring(endPos, myField.value.length);
var pos = startPos + myValue.length;
myField.focus();
myField.setSelectionRange(pos, pos);
}
//MOZILLA and others
else if (myField.selectionStart || myField.selectionStart == '0') {
var startPos = myField.selectionStart;
var endPos = myField.selectionEnd;
myField.value = myField.value.substring(0, startPos)
+ myValue
+ myField.value.substring(endPos, myField.value.length);
} else {
myField.value += myValue;
}
triggerEvent(myField,'input');
}
function triggerEvent(el, type){
if ('createEvent' in document) {
// modern browsers, IE9+
var e = document.createEvent('HTMLEvents');
e.initEvent(type, false, true);
el.dispatchEvent(e);
} else {
// IE 8
var e = document.createEventObject();
e.eventType = type;
el.fireEvent('on'+e.eventType, e);
}
}
归功于 plainjs.com的 triggerEvent 函数
更多关于w3schools.com上的 oninput 事件
我在为聊天创建表情符号选择器时发现了这一点。 如果用户只是选择几个表情符号并点击“发送”按钮,则用户永远不会触摸输入字段。 检查 value 属性时,它始终为空,即使插入的表情符号 unicode 在输入字段中可见。 事实证明,如果用户不触摸该字段,则“输入”事件永远不会触发,解决方案是像这样触发它。 花了很长时间才弄清楚这个……希望它能节省一些时间。
function insertAtCaret(text) { const textarea = document.querySelector('textarea') textarea.setRangeText( text, textarea.selectionStart, textarea.selectionEnd, 'end' ) } setInterval(() => insertAtCaret('Hello'), 3000)
<textarea cols="60">Stack Overflow Stack Exchange Starbucks Coffee</textarea>
下面的代码是 Dmitriy Kubyshkin 对包https://github.com/grassator/insert-text-at-cursor的 TypeScript 改编。
/**
* Inserts the given text at the cursor. If the element contains a selection, the selection
* will be replaced by the text.
*/
export function insertText(input: HTMLTextAreaElement | HTMLInputElement, text: string) {
// Most of the used APIs only work with the field selected
input.focus();
// IE 8-10
if ((document as any).selection) {
const ieRange = (document as any).selection.createRange();
ieRange.text = text;
// Move cursor after the inserted text
ieRange.collapse(false /* to the end */);
ieRange.select();
return;
}
// Webkit + Edge
const isSuccess = document.execCommand("insertText", false, text);
if (!isSuccess) {
const start = input.selectionStart;
const end = input.selectionEnd;
// Firefox (non-standard method)
if (typeof (input as any).setRangeText === "function") {
(input as any).setRangeText(text);
} else {
if (canManipulateViaTextNodes(input)) {
const textNode = document.createTextNode(text);
let node = input.firstChild;
// If textarea is empty, just insert the text
if (!node) {
input.appendChild(textNode);
} else {
// Otherwise we need to find a nodes for start and end
let offset = 0;
let startNode = null;
let endNode = null;
// To make a change we just need a Range, not a Selection
const range = document.createRange();
while (node && (startNode === null || endNode === null)) {
const nodeLength = node.nodeValue.length;
// if start of the selection falls into current node
if (start >= offset && start <= offset + nodeLength) {
range.setStart((startNode = node), start - offset);
}
// if end of the selection falls into current node
if (end >= offset && end <= offset + nodeLength) {
range.setEnd((endNode = node), end - offset);
}
offset += nodeLength;
node = node.nextSibling;
}
// If there is some text selected, remove it as we should replace it
if (start !== end) {
range.deleteContents();
}
// Finally insert a new node. The browser will automatically
// split start and end nodes into two if necessary
range.insertNode(textNode);
}
} else {
// For the text input the only way is to replace the whole value :(
const value = input.value;
input.value = value.slice(0, start) + text + value.slice(end);
}
}
// Correct the cursor position to be at the end of the insertion
input.setSelectionRange(start + text.length, start + text.length);
// Notify any possible listeners of the change
const e = document.createEvent("UIEvent");
e.initEvent("input", true, false);
input.dispatchEvent(e);
}
}
function canManipulateViaTextNodes(input: HTMLTextAreaElement | HTMLInputElement) {
if (input.nodeName !== "TEXTAREA") {
return false;
}
let browserSupportsTextareaTextNodes;
if (typeof browserSupportsTextareaTextNodes === "undefined") {
const textarea = document.createElement("textarea");
textarea.value = "1";
browserSupportsTextareaTextNodes = !!textarea.firstChild;
}
return browserSupportsTextareaTextNodes;
}
发布修改功能供自己参考。 此示例从<select>
对象插入一个选定项目,并将插入符号放在标记之间:
//Inserts a choicebox selected element into target by id
function insertTag(choicebox,id) {
var ta=document.getElementById(id)
ta.focus()
var ss=ta.selectionStart
var se=ta.selectionEnd
ta.value=ta.value.substring(0,ss)+'<'+choicebox.value+'>'+'</'+choicebox.value+'>'+ta.value.substring(se,ta.value.length)
ta.setSelectionRange(ss+choicebox.value.length+2,ss+choicebox.value.length+2)
}
/**
* Usage "foo baz".insertInside(4, 0, "bar ") ==> "foo bar baz"
*/
String.prototype.insertInside = function(start, delCount, newSubStr) {
return this.slice(0, start) + newSubStr + this.slice(start + Math.abs(delCount));
};
$('textarea').bind("keydown keypress", function (event) {
var val = $(this).val();
var indexOf = $(this).prop('selectionStart');
if(event.which === 13) {
val = val.insertInside(indexOf, 0, "<br>\n");
$(this).val(val);
$(this).focus();
}
});
扩展阿德里亚诺的答案,我们也可以考虑光标结束这将使“替换文本”工作
$('input[type=button]').on('click', function() {
var cursorStart = $('#text').prop('selectionStart');
var cursorEnd = $('#text').prop('selectionEnd');
var v = $('#text').val();
var textBefore = v.substring(0,cursorStart);
var textAfter = v.substring(cursorEnd);
$('#text').val(textBefore + $(this).val() + textAfter);
});
将其更改为getElementById(myField)
:
function insertAtCursor(myField, myValue) {
// IE support
if (document.selection) {
document.getElementById(myField).focus();
sel = document.selection.createRange();
sel.text = myValue;
}
// MOZILLA and others
else if (document.getElementById(myField).selectionStart || document.getElementById(myField).selectionStart == '0') {
var startPos = document.getElementById(myField).selectionStart;
var endPos = document.getElementById(myField).selectionEnd;
document.getElementById(myField).value =
document.getElementById(myField).value.substring(0, startPos)
+ myValue
+ document.getElementById(myField).value.substring(endPos, document.getElementById(myField).value.length);
} else {
document.getElementById(myField).value += myValue;
}
}
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