[英]How to insert text into the textarea at the current cursor position?
我想創建一個簡單的函數,將文本添加到用戶光標位置的文本區域中。 它需要是一個干凈的功能。 只是基礎知識。 我可以弄清楚其余的。
使用輸入元素的selectionStart
/ selectionEnd
屬性(也適用於<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;
}
}
這個片段可以在幾行 jQuery 1.9+ 中幫助你: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
我不確定瀏覽器對此的支持。
在 Chrome 81 中測試。
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 回答的純 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 中測試。
如果您想在輸入同一字段時更改當前選定文本的值(用於自動完成或類似效果),請將document.activeElement
作為第一個參數傳遞。
這不是最優雅的方法,但它非常簡單。
示例用法:
typeInTextarea('hello');
typeInTextarea('haha', document.getElementById('some-id'));
為了正確的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;
}
};
一個簡單的解決方案,適用於 firefox、chrome、opera、safari 和 edge,但可能不適用於舊的 IE 瀏覽器。
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
函數允許您用提供的文本替換當前選擇,或者如果沒有選擇,則在光標位置插入文本。 據我所知,它僅受 Firefox 支持。
對於其他瀏覽器,“insertText”命令僅影響當前聚焦的 html 元素,並且具有與setRangeText
相同的行為
部分靈感來自這篇文章
我喜歡簡單的javascript ,而且我通常有jQuery 。 這是我根據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
})
這是一個演示: http ://codepen.io/erikpukinskis/pen/EjaaMY?editors=101
Rab 的回答效果很好,但不適用於 Microsoft Edge,所以我也為 Edge 添加了一個小的改編:
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;
}
}
如果用戶在插入文本后沒有觸摸輸入,則永遠不會觸發 'input' 事件,並且 value 屬性不會反映更改。 因此,在以編程方式插入文本后觸發輸入事件很重要。 聚焦領域是不夠的。
以下是Snorvarg 的答案副本,最后帶有輸入觸發器:
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);
}
}
歸功於 plainjs.com的 triggerEvent 函數
更多關於w3schools.com上的 oninput 事件
我在為聊天創建表情符號選擇器時發現了這一點。 如果用戶只是選擇幾個表情符號並點擊“發送”按鈕,則用戶永遠不會觸摸輸入字段。 檢查 value 屬性時,它始終為空,即使插入的表情符號 unicode 在輸入字段中可見。 事實證明,如果用戶不觸摸該字段,則“輸入”事件永遠不會觸發,解決方案是像這樣觸發它。 花了很長時間才弄清楚這個……希望它能節省一些時間。
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>
下面的代碼是 Dmitriy Kubyshkin 對包https://github.com/grassator/insert-text-at-cursor的 TypeScript 改編。
/**
* 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;
}
發布修改功能供自己參考。 此示例從<select>
對象插入一個選定項目,並將插入符號放在標記之間:
//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();
}
});
擴展阿德里亞諾的答案,我們也可以考慮光標結束這將使“替換文本”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);
});
將其更改為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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