我设置了一个按钮,单击该按钮将通过获取发布数据并创建警报。但是,我首先检查以确保某些输入不为空。如果输入元素没有值,我尝试返回一个字符串,告诉我哪个输入元素值是空的。当我这样做时,会出现“ Uncaught TypeError:postData(...)。then not a function”错误。我也查看了Uncaught TypeError: $.get(...).then is not a function,但无法弄清楚。任何帮助将不胜感激。谢谢!
document.getElementById("sbmForm").onclick = function () {postData(`/projectInfo`)
.then(result => alert(JSON.stringify(result))) // JSON-string from `response.json()` call
.catch(error => alert(error))};
function postData(url = ``) {
// get form data from local storage
var data = {};
var unqVal = document.getElementById("unq_num").innerHTML;
unqVal = "--??**" + unqVal;
// keys that can not be empty
var notEmpty = ["comp_name", "compaddr_str_num", "compaddr_str_nam", "compaddr_city",
"compaddr_state", "compaddr_zipcode", "proj_name", "projaddr_str_num", "projaddr_str_nam",
"projaddr_city", "projaddr_state", "projaddr_zipcode", "contact_fname", "contact_date"];
/* get all keys and values from local storage and store them in dict to send to server */
var keys = Object.keys(localStorage);
var i;
for (i=0; i < keys.length; i++){
var val = localStorage.getItem(keys[i]);
// if unq val is in string, add it to the data
var indexOf = keys[i].indexOf(unqVal);
if (indexOf != -1){
var keyNU = keys[i].substring(0, indexOf);
// if value is in array
if (notEmpty.includes(keyNU)){
// if value is empty
if (!val){
alert(keyNU + " cannot be empty!");
/**** ERROR OCCURS HERE *****/
return keyNU + " cannot be empty!";
}
}
data[keys[i]] = val;
}
}
// Default options are marked with *
return fetch(url, {
method: "POST",
headers: {
"Content-Type": "application/json",
},
body: JSON.stringify(data), // body data type must match "Content-Type" header
})
.then(response => response.json()); // parses response to JSON
};
答案 0 :(得分:2)
当检测到“错误”时,您将返回字符串值而不是promise。 then
方法仅在promise上存在。
将您的function
更改为async
,以便默认情况下返回promise
。
async function postData(url = ``){}
然后在需要更改时抛出错误(将被catch
方法捕获)
/**** ERROR OCCURS HERE *****/
return keyNU + " cannot be empty!";
收件人
throw new Error(keyNU + " cannot be empty!");
最后,为您提取内容:
//fetch returns a promise, so use await
const res = await fetch(url, {
method: "POST",
headers: {
"Content-Type": "application/json",
},
body: JSON.stringify(data), // body data type must match "Content-Type" header
});
//res.json() returns a promise, so use await
return await res.json();