[英]Cannot Pass Callback Function On Mouseup Event - JavaScript
I'm trying to pass a callback function as an argument in a previous function that is triggered by a mouseup in a chrome extension. 我试图将回调函数作为参数传递给chrome扩展程序中的mouseup触发的先前函数。 So basically I'm aiming to trigger the quickTranslate function right after the lwsGetText finishes running.
因此,基本上我的目标是在lwsGetText完成运行后立即触发quickTranslate函数。 But I can't figure out how to do this since the function lwsGetText is triggered by a mouseup.
但是由于函数lwsGetText是由mouseup触发的,所以我不知道该怎么做。 Here's my code:
这是我的代码:
Content Script (js) 内容脚本(js)
(function () {
// Holds text being selected in browser
var lwsSelectedText = '';
// Adds pop-up to current webpage
function lwsAddContent(callback) {
// Get body tag
var body = document.getElementsByTagName('body');
// add invisible div
document.body.innerHTML += '<div id="myModal" class="modal"><div class="modal-content"><span class="close">×</span><div id="lwsSpanishDiv"><p id="lwsSpanishTitle">Spanish</p><textarea id="lwsSpanishTextArea">Hello</textarea></div><div id="lwsEnglishDiv"><p id="lwsEnglishTitle">English</p><textarea id="lwsEnglishTextArea">Hello 2</textarea></div></div></div>';
callback(lwsSetUpTextGetter);
}
// Make the pop-up visible and set up close button
function lwsActivateContent(callback) {
var modal = document.getElementById('myModal');
// Get the textarea
var txtarea = document.getElementById("myTxtArea");
// Get the <span> element that closes the modal
var span = document.getElementsByClassName("close")[0];
span.onclick = function () {
modal.style.display = "none";
}
callback(quickTranslate);
}
// Initialize ability to select and grab text from browser
function lwsSetUpTextGetter(callback) {
//Set the onmouseup function to lwsGetText
document.onmouseup = lwsGetText;
//Handling clicking outside webpage?
if (!document.all) document.captureEvents(Event.MOUSEUP);
}
//Gets selected text
function lwsGetText(callback,e) {
// Get access to spanish text area
var spanishText = document.getElementById('lwsSpanishTextArea');
//Get text
lwsSelectedText = (document.all) ? document.selection.createRange().text : document.getSelection();
//if nothing is selected, do nothing
if (lwsSelectedText != '') {
// test: does browser grab text correctly?
alert(lwsSelectedText);
// Set spanish text area content to the selected text from browser
spanishText.value = lwsSelectedText;
// --Error Here--
callback();
}
}
function quickTranslate() {
alert("Quick Translate");
var url = "https://translate.yandex.net/api/v1.5/tr.json/translate",
keyAPI = "trnsl.1.1.20130922T110455Z.4a9208e68c61a760.f819c1db302ba637c2bea1befa4db9f784e9fbb8";
var englishTextArea = document.getElementById('lwsEnglishTextArea');
var spanishTextArea = document.getElementById('lwsSpanishTextArea');
englishTextArea.value = 'Working...';
var xhr = new XMLHttpRequest(),
textAPI = spanishTextArea.value,
langAPI = 'en';
data = "key=" + keyAPI + "&text=" + textAPI + "&lang=" + langAPI;
xhr.open("POST", url, true);
xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhr.send(data);
xhr.onreadystatechange = function () {
if (this.readyState == 4 && this.status == 200) {
var res = this.responseText;
var json = JSON.parse(res);
if (json.code == 200) {
englishTextArea.value = json.text[0];
}
else {
englishTextArea.value = "Error Code: " + json.code;
}
}
}
}
// When document ready
$(document).ready(function () {
lwsAddContent(lwsActivateContent);
});
})();
If someone could help me figure out how to implement the quickTranslate function as a callback function, that would be awesome! 如果有人可以帮助我弄清楚如何将quickTranslate函数实现为回调函数,那就太好了! Thanks!
谢谢!
As you know the event handler you're assigning takes one parameter, the event. 如您所知,您要分配的事件处理程序采用一个参数,即事件。 However you can create a closure around the "callback" variable by doing something like:
但是,您可以通过执行以下操作来围绕“回调”变量创建一个闭包:
function lwsGetText(callback) {
return function (e) {
// Get access to spanish text area
var spanishText = document.getElementById('lwsSpanishTextArea');
//Get text
lwsSelectedText = (document.all) ? document.selection.createRange().text : document.getSelection();
//if nothing is selected, do nothing
if (lwsSelectedText != '') {
// test: does browser grab text correctly?
alert(lwsSelectedText);
// Set spanish text area content to the selected text from browser
spanishText.value = lwsSelectedText;
// --Error Here--
callback();
}
};
}
You would then pass the value quickTranslate as the "callback" parameter when you set the handler, not sure how you're doing that so here is a guess: 然后,在设置处理程序时,您需要将值quickTranslate传递为“回调”参数,不确定执行该操作的方式,所以这里是一个猜测:
myElement.addEventListener("mouseup", lwsGetText(quickTranslate));
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