Question

我有一个扩展，需要聚焦当前窗口才能提交表单。提交此表单可能要花费几秒钟的时间，即使另一个标签调用了chrome.runtime.sendMessage()

，我也不希望该标签切换到下一个表单提交

// content_script.js

if (!Document.visibilityState === ""visible) {
  chrome.runtime.sendMessage("Focus", function(resp) {
    reply_link.click()
    setTimeout(function() {
      // from here, let the background script know it's OK to continue
      // if background.js tries to call another tab from here it is blocked from doing so
    }, 1000)
  })
}


// background.js

chrome.runtime.onMessage.addListener(function(request, sender, sendResponse){
  chrome.tabs.update(sender.tab.id, {"active": true}, function(tab){
    return sendResponse(tab)
  });
  return true
});

Answer 1

发送时间等待同一条消息，以便后台脚本可以管理内部的队列：

content_script.js

chrome.runtime.sendMessage({action: 'focus', wait: 1000}, response => {
  reply_link.click()
});

background.js

const queue = [];

const ACTIONS = {

  focus(task) {
    chrome.tabs.update(task.sender.tab.id, {active: true}, tab => {
      task.response = tab;
      callOrWait(processQueue, task.msg.wait);
    });
    return true;
  },

};

chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
  queue.push({msg, sender, sendResponse});
  return queue.length > 1 || processQueue();
  // returning 'true' postpones the response thus pausing the sender when there is 
  // already a task in the queue and once that completes this one will be processed
});

function processQueue() {
  while (queue.length) {
    const task = queue.shift();
    if ('response' in task) {
      task.sendResponse(task.response);
      continue;
    }
    const action = ACTIONS[task.msg.action];
    if (action && action(task) === true) {
      // this task wants an asynchronous response 
      return true;
    }
  }
}

function callOrWait(fn, wait, ...args) {
  if (wait) {
    setTimeout(fn, wait, ...args);
  } else {
    fn(...args);
  }
}

Chrome扩展程序具有后台脚本，直到制表符操作完成

1 个答案: