如何检查图片是否上传？AJAX PHP

Question

我正试图开发一个web应用程序，在那里你可以创建帖子，并有一个(只是一个)图像，但你不需要有一个，它也可以只是一个文本帖子。这只是一个个人项目，试图使php和ajax变得更好，所以我可能做错了.我想要做的是将表单数据提交给一个php函数，这个函数将决定是否上传它，那么我想要做的是，如果它成功地将图像名发送到另一个函数，将post插入到数据库中，但是如果图像上传没有成功地显示错误。此外，如果它不是成功的，但错误是‘没有图片上传’，继续继续并创建文章无论如何。

这是我到目前为止所拥有的

The jQuery

   $(".new-post").submit(function (e) {

    e.preventDefault();

    $.ajax({
        type: "post",
        url: "includes/image-upload.php",
        data: new FormData(this),
        processData: false,
        contentType: false,
        error: function (response) {
            console.log(response);
        },
        success: function (response) {
            var body = $("#post-body").val();
            $.ajax({
                type: "post",
                url: "create-post-feed.php",
                data: {
                    body: body,
                    image: response
                },
                error: function (response) {
                    console.log(response);
                },
                success: function (response) {
                    //                        console.log(response);
                    $('section.feed').prepend(response);
                    $('article.post p').each(function () {
                        $(this).html(linkHashtags($(this).html()));
                    });
                    $('article.post p').each(function () {
                        $(this).html(linkatsymbols($(this).html()));
                    });
                    revealPosts();
                }
            });
        }
    });

});

在进行了一些研究之后，我发现如果这是一个错误，我必须将它作为JSON发送回来，然后在jQuery中检查结果。但是我还没有开始工作..。

<?php

require_once('../dbconnect.php');
include_once( INCLUDES_PATH .'functions.php');

function uploadFile ($file_field = null, $check_image = false, $random_name = false) {

//Config Section 
$user_id = $_SESSION['user_id'];
//check if directory exist if not create it
if (!file_exists(HOME_PATH ."users/user_".$user_id)) {
    mkdir(HOME_PATH ."users/user_".$user_id, 0777, true);
}
if (!file_exists(HOME_PATH ."users/user_".$user_id."/posts")) {
    mkdir(HOME_PATH ."users/user_".$user_id."/posts", 0777, true);
}
//Set file upload path
$path = "../users/user_".$user_id."/posts/"; //with trailing slash
//Set max file size in bytes
$max_size = 1000000;
//Set default file extension whitelist
$whitelist_ext = array('jpeg','jpg','png','gif');
//Set default file type whitelist
$whitelist_type = array('image/jpeg', 'image/jpg', 'image/png','image/gif');

//The Validation
// Create an array to hold any output
$out = array('error'=>null);

if (!$file_field) {
    $out['error'][] = "Please specify a valid form field name";           
}

if (!$path) {
    $out['error'][] = "Please specify a valid upload path";               
}

if (count($out['error'])>0) {
    return $out;
}

//Make sure that there is a file
if((!empty($_FILES[$file_field])) && ($_FILES[$file_field]['error'] == 0)) {

    // Get filename
    $file_info = pathinfo($_FILES[$file_field]['name']);
    $name = $file_info['filename'];
    $ext = $file_info['extension'];

    //Check file has the right extension           
    if (!in_array($ext, $whitelist_ext)) {
        $out['error'][] = "Invalid file Extension";
    }

    //Check that the file is of the right type
    if (!in_array($_FILES[$file_field]["type"], $whitelist_type)) {
        $out['error'][] = "Invalid file Type";
    }

    //Check that the file is not too big
    if ($_FILES[$file_field]["size"] > $max_size) {
        $out['error'][] = "File is too big";
    }

    //If $check image is set as true
    if ($check_image) {
        if (!getimagesize($_FILES[$file_field]['tmp_name'])) {
            $out['error'][] = "Uploaded file is not a valid image";
        }
    }

    //Create full filename including path
    if ($random_name) {
        // Generate random filename
        $tmp = str_replace(array('.',' '), array('',''), microtime());

    if (!$tmp || $tmp == '') {
        $out['error'][] = "File must have a name";
    }     
        $newname = $tmp.'.'.$ext;                                
    } else {
        $newname = $name.'.'.$ext;
    }

    //Check if file already exists on server
    if (file_exists($path.$newname)) {
        $out['error'][] = "A file with this name already exists";
    }

    if (count($out['error'])>0) {
        //The file has not correctly validated
        return $out;
    } 
    if (move_uploaded_file($_FILES[$file_field]['tmp_name'], $path.$newname)) {
        echo $newname;
    } else {
        $out['error'][] = "Server Error!";
    }
 } else {
    $out['error'][] = "No file uploaded";
    return $out;
 }      
}

$file = uploadFile('file', true, true);

if (is_array($file['error'])) {
echo json_encode($file['error']);
}

die();

真正感谢任何帮助或评论，如何使它更好的BTW，这目前的工作，唯一的问题是，帖子总是创建，无论图片上传与否。

通常我至少会在同一天得到答案..。这个问题有那么糟吗？我听说编辑的XD会帮你解决这个问题

Answer 1

你说你想做的和你实际做的不一样。在您的代码中，您正在尝试两个AJAX调用：(1)上传图像，(2)保存post。

为什么不在一个电话里同时做两件事呢？这样，您就不必等待上传图片(或无)的响应才能创建新的帖子。

$(".new-post").submit(function (e) {
    e.preventDefault();
    $.ajax({
        type: "post",
        url: "create-post-feed.php",
        data: new FormData(this), // send post information including selected file
        processData: false,
        contentType: false,
        error: function (response) {
            console.log(response);
        },
        success: function (response) {
            // etc
        }
    });
});

然后在create-post-feed.php中，将image-upload.php中的逻辑与当前代码合并。我通常是这样做的：

// validate post

// validate image (if any)

// if no errors:

    // upload image (if any) and retrieve filename

// if no errors:

    // save post (with filename if any); if it fails, delete image (if any)

// send response