Question

我已经将自己的方法pushLocalStorage（）创建到我的background.js中，以便于将对象附加到对象数组中。它的目的是简单地从调用者获取数据，如果密钥存在，则将数据对象推送到先前迭代中存储的现有数组。如果密钥不存在，则创建一个新的数组indice。

第一个对象的创建工作正常。第二次插入成功完成但插入数组的长度而不是对象。最后，第三个和任何后续插入失败，因为数据不再是数组而是字符串，我的代码在插入数据之前验证数据是否为数组。请参阅代码后的示例日志记录：

这是我的代码：

else if (request.method == 'pushLocalStorage')      
{
    var key; 
    var data;
    var stored;

    // if key isn't sent from caller, quit with error.
    if ( 'undefined' == typeof(request.key) )
    {
        sendResponse({success: 0,error: 'Key value was not sent from caller.'});
    }

    // if the key isn't a string type then quit with error.
    if ( 'string' != typeof(request.key) )
    {
        sendResponse({success: 0,error: 'Expected key passed from caller to be a ' + 
                                        'string but it was a(n) ' + typeof(request.key) + ' instead'});
    }

    // if data value isn't sent from caller, quit with error.
    if ( 'undefined' == typeof(request.data) )
    {
        sendResponse({success: 0,error: 'Data value was not sent from caller.'});
    }

    key    = request.key;
    data   = request.data;
    stored = localStorage.getItem(key); // attempt to retrieve existing store named by 'key'

    // Now if stored isn't null or undefined...
    if ( 'undefined' != typeof(stored) && stored != null )
    {
        // parse it back into a valid data structure from JSON
        stored = JSON.parse(stored);

        // if stored exists (should be an Array object)
        if ( stored.length )
        {
            // stored should be an array of objects so...
            for ( var i = 0 ; stored.length < i ; i++ )
            {
                // make sure not to push dupe tickets into the array. In this case, replace
                // the existing ticket with the new.
                if ( data.id === stored[i].id )
                {
                    stored[i] = data;

                    // save the data to localStorage (do not push but overwrite)
                    localStorage.setItem(key,JSON.stringify(stored));
                    test = JSON.parse(localStorage.getItem(key));
                    sendResponse({success: 1,data: test});
                    return;
                }
            }

            // save the stored object back to localStorage after pushing the new data to it.
            localStorage.setItem(key,stored.push(JSON.stringify(data)));
            test = JSON.parse(localStorage.getItem(key));
            sendResponse({success: 1,data: test});
        }
        else
        {
            console.log(' data would be: %o and stored was: %o', data,stored);
            sendResponse({success: 0, error: 'Attempt to coerce object into array not allowed.'});
        }
    }
    else
    {
        console.debug(' Creating new array to be stored.');
        stored = new Array(data);
        stored = JSON.stringify(stored);

        localStorage.setItem(key,stored);

        test = localStorage.getItem(key);
        test = JSON.parse(test);
        console.log('setItem.' + key + ',' + stored + '\nThe stored obj was: %o and the localStored.getItem after storage was: %o',test,localStorage.getItem(key));
        sendResponse({success: 1,data: test});
    }
}

在Chrome控制台中，我得到以下内容：

Object  
localstorage push! [Object]:  
Object
localstorage push! [Object]:
Object
localstorage push! [Object]:
Object
localstorage push! [Object]:
Object
localstorage push! 2:  
Object
localstorage push! [Object]: 
Object
localstorage push! 2:
Object
localstorage push failed: Attempt to coerce object into array not allowed. 
Object
localstorage push failed: Attempt to coerce object into array not allowed.
Object
localstorage push! [Object]:
Object
localstorage push! 2:
Object
localstorage push failed: Attempt to coerce object into array not allowed.

因此，在尝试了几种不同的编码功能的方法之后，似乎没有任何工作。我是在咆哮错误的树还是我只编写了一个糟糕的实现？

TIA

编辑：

修复完成代码：

if (request.method == 'pushLocalStorage')       
{
    var key; 
    var data;
    var stored;

    // if key isn't sent from caller, quit with error.
    if ( 'undefined' == typeof(request.key) )
    {
        sendResponse({success: 0,error: 'Key value was not sent from caller.'});
    }

    // if the key isn't a string type then quit with error.
    if ( 'string' != typeof(request.key) )
    {
        sendResponse({success: 0,error: 'Expected key passed from caller to be a ' + 
                                        'string but it was a(n) ' + typeof(request.key) + ' instead'});
    }

    // if data value isn't sent from caller, quit with error.
    if ( 'undefined' == typeof(request.data) )
    {
        sendResponse({success: 0,error: 'Data value was not sent from caller.'});
    }

    key    = request.key;
    data   = request.data;
    stored = localStorage.getItem(key); // attempt to retrieve existing store named by 'key'

    // Now if stored isn't null or undefined...
    if ( 'undefined' != typeof(stored) && stored != null )
    {
        // parse it back into a valid data structure from JSON
        stored = JSON.parse(stored);

        // if stored exists (should be an Array object)
        if ( stored.length )
        {
            // stored should be an array of objects so...
            for ( var i = 0 ; i < stored.length ; i++ )
            {
                // make sure not to push dupe tickets into the array. In this case, replace
                // the existing ticket with the new.
                if ( data.id === stored[i].id )
                {
                    stored[i] = data;

                    // purge the item...
                    localStorage.removeItem(key);

                    // save the data to localStorage.
                    localStorage.setItem(key,JSON.stringify(stored));

                    data = JSON.parse(localStorage.getItem(key));
                    sendResponse({success: 1,data: data});
                    return;
                }
            }

            // save the stored object back to localStorage after pushing the new data to it.
            stored.push(data);
            localStorage.setItem(key,JSON.stringify(stored));
            data = JSON.parse(localStorage.getItem(key));
            sendResponse({success: 1,data: data});
        }
        else
        {
            sendResponse({success: 0, error: 'Attempt to coerce object into array not allowed.'});
        }
    }

Answer 1

好的。弄清楚了。当我应该一直在摇摆时，我正在挣扎：

错：

localStorage.setItem(key,stored.push(JSON.stringify(data)));

右：

stored.push(data);
localStorage.setItem(key,JSON.stringify(stored));

test = JSON.parse(localStorage.getItem(key));
sendResponse({success: 1,data: test});

问题是我试图将字符串化的值推送到数组对象中。是的，不能那样做。一旦我修好了，一切都很好。

chrome扩展：将JSON数据追加（推送）到localStorage（）

1 个答案: