将画布中上传的图像保存到服务器

时间:2019-07-12 10:36:29

标签: javascript jquery html5-canvas

我们正在从json获取蒙版图像并在页面中显示。单击蒙版后,将显示“文件上传”对话框,以便用户上传图像。

enter image description here

要求

一旦用户单击保存按钮,我想将该图像上传到服务器。...但是现在它没有将图像保存在服务器中。...

Codepen:https://codepen.io/kidsdial/pen/pXBRga

脚本

function test(){
var canvas  = document.getElementById("cvs");
var dataURL = canvas.toDataURL();

$.ajax({
  type: "POST",
  url: "upload.php",
  data: { 
     imgBase64: dataURL
  }
}).done(function(o) {
  console.log('saved'); 

});

}

Upload.php

<?php    
define('UPLOAD_DIR', 'uploads/');
imgBase64 = $_POST['img'];
$img = str_replace('data:image/png;base64,', '', $img);
$img = str_replace(' ', '+', $img);
$data = base64_decode($img);
$file = UPLOAD_DIR . uniqid() . '.png';
$success = file_put_contents($file, $data);
print $success ? $file : 'Unable to save the file.';
?> 

以下是代码段:

var target;
const imageUrl = "https://i.imgur.com/RzEm1WK.png";

let jsonData = {
    "layers": [{
        "x": 0,
        "height": 400,
        "layers": [{
            "x": 20,
            "src": "ax0HVTs.png",
            "y": 20,
            "height": 296,
            "width": 429,
            "name": "mask_1"
        }],
        "y": 0,
        "width": 500
    }]
};

const containerElement = $('#container');
const fileUp = $('#fileup');
let mask;

$(function() {

    // Upload image onclick mask image
	
    containerElement.click(function(e) {
        var res = e.target;
        target = res.id;
        if (e.target.getContext) {
            // click only inside Non Transparent part 
            var pixel = e.target.getContext('2d').getImageData(e.offsetX, e.offsetY, 1, 1).data;
            if (pixel[3] === 255) {
                setTimeout(() => {
                    $('#fileup').click();
                }, 20);
            }
        }
    });

    // Fetch mask images from json file

    function getAllSrc(layers) {
        let arr = [];
        layers.forEach(layer => {
            if (layer.src) {
                arr.push({
                    src: layer.src,
                    x: layer.x,
                    y: layer.y,
                    height: layer.height,
                    width: layer.width,
                    name: layer.name
                });
            } else if (layer.layers) {
                let newArr = getAllSrc(layer.layers);
                if (newArr.length > 0) {
                    newArr.forEach(({
                        src,
                        x,
                        y,
                        height,
                        width,
                        name
                    }) => {
                        arr.push({
                            src,
                            x: (layer.x + x),
                            y: (layer.y + y),
                            height,
                            width,
                            name: (name)
                        });
                    });
                }
            }
        });
        return arr;
    }

    function json(data) {
        var width = 0;
        var height = 0;

        let arr = getAllSrc(data.layers);
        let layer1 = data.layers;
        width = layer1[0].width;
        height = layer1[0].height;
        let counter = 0;
        let table = [];

        containerElement.css('width', width + "px").css('height', height + "px").addClass('temp');

        for (let {
                src,
                x,
                y,
                name
            } of arr) {

            var ImagePosition = arr;

            var imageUrl1 = imageUrl;

            var mask = $(".container").mask({
                imageUrl: name.indexOf('mask_') !== -1 ? imageUrl1 : undefined,

                // Mask images
                maskImageUrl: 'https://i.imgur.com/' + src,
                // end

                onMaskImageCreate: function(img) {
                    // Mask image positions
                    img.css({
                        "position": "absolute",
                        "left": x + "px",
                        "top": y + "px"
                    });
                    // end

                },
                id: counter
            });

            ImagePosition.map(function(cur, index) {
                var available = cur.name.includes('mask_');

                if (!available) {
                    $('.masked-img' + index).css('pointer-events', 'none');
                }
            });

            table.push(mask);
            fileup.onchange = function() {

                let mask2 = table[target];
                const newImageLoadedId = mask2.loadImage(URL.createObjectURL(fileup.files[0]));
                document.getElementById('fileup').value = "";                
            };
            counter++;
        }       
        return mask;
    }

    mask = json(jsonData);
}); // end of function

// Image code

(function($) {
    window.JQmasks = [];
    $.fn.mask = function(options) {
        // This is the easiest way to have default options.
        const settings = $.extend({
            // These are the defaults.
            maskImageUrl: undefined,
            imageUrl: undefined,
            scale: 1,
            id: new Date().getUTCMilliseconds().toString(),
            x: 0, // image start position
            y: 0, // image start position
            onMaskImageCreate: function(div) {},
            rotate: 0,
        }, options);

        // Create the image properties
        settings.maskImage = new Image
        settings.image = new Image

        // set the cross-origin attributes
        settings.maskImage.setAttribute('crossOrigin', 'anonymous');
        settings.image.setAttribute('crossOrigin', 'anonymous');

        settings.maskImage.onload = function() {
            // once the mask is loaded, load the image
            container.loadImage(settings.imageUrl, true)
            container.drawMask()
        }

        settings.image.onload = function() {
            // once the image is loaded, render to canvas            
            container.drawImage()
        }

        var container = $(this);

        let prevX = 0,
            prevY = 0,
            draggable = false,
            img,
            canvas,
            context,
            image,
            timeout,
            initImage = false,
            startX = settings.x,
            startY = settings.y,
            scale = settings.scale,
            div;

        container.mousePosition = function(event) {
            return {
                x: event.pageX || event.offsetX,
                y: event.pageY || event.offsetY
            };
        }

        container.selected = function(ev) {
            var pos = container.mousePosition(ev);
            var item = ev.currentTarget;

            JQmasks.forEach(function(el) {
                var id = $(item).attr("id");
                if (el.id == id)
                    el.item.enable();
                else
                    el.item.disable();
            });
        };

        container.enable = function() {
            draggable = true;
            $(canvas).attr("active", "true");
            div.css({
                "z-index": 2
            });
        }

        container.disable = function() {
            draggable = false;
            $(canvas).attr("active", "false");
            div.css({
                "z-index": 1
            });
        }

        container.getImagePosition = function() {
            return {
                x: settings.x,
                y: settings.y,
                scale: settings.scale
            };
        };

        
        container.drawMask = function() {
            if (!settings.maskImage) return true;
            canvas.width = settings.maskImage.width;
            canvas.height = settings.maskImage.height;
            context.save();
            context.beginPath();
            context.globalCompositeOperation = "source-over";
            // draw the masked image after scaling
            if (settings.maskImage)
                context.drawImage(settings.maskImage, 0, 0, settings.maskImage.width, settings.maskImage
                    .height);
            context.restore()
        };

        container.drawImage = function() {
            const img = settings.image

            settings.x = settings.x == 0 && initImage ? (canvas.width - (img.width * settings.scale)) / 2 : settings.x;
            settings.y = settings.y == 0 && initImage ? (canvas.height - (img.height * settings.scale)) / 2 : settings.y;

            context.globalCompositeOperation = 'source-atop';
            context.save();
            context.translate(settings.x + img.width / 2, settings.y + img.height / 2);
            context.rotate(settings.rotate);
            context.scale(settings.scale, settings.scale);
            context.translate(-(settings.x + img.width / 2), -(settings.y + img.height / 2));
            let width = img.width,
                height = img.height;
            if (img)
                context.drawImage(img, settings.x, settings.y, width, height);
            context.restore();
            initImage = false;          
        }

        container.loadImage = function(imageUrl, isMask) {
            if (!imageUrl) return true;
            settings.y = startY;
            settings.x = startX;
            settings.scale = 1;
            settings.rotate = 0;
            prevX = prevY = 0;
            initImage = true;
            settings.image.src = imageUrl; // CHANGED
            if (!isMask)
                container.data('image_set' + settings.id, true)
            return settings.id;
        };
          
        container.loadMaskImage = function(imageUrl, from) {
            // console.log('loading mask image from', imageUrl, from)
            canvas = document.createElement("canvas");
            context = canvas.getContext('2d');
            canvas.setAttribute("draggable", "true");
            canvas.setAttribute("id", settings.id);
            // settings.maskImageUrl = imageUrl;
            settings.maskImage.src = imageUrl // CHANGED

            div = $("<div/>", {
                "class": "masked-img"
            }).append(canvas);
          
            container.append(div);
            if (settings.onMaskImageCreate)
                settings.onMaskImageCreate(div);
        };

        if (settings.maskImageUrl) {
            container.loadMaskImage(settings.maskImageUrl);
        }
        JQmasks.push({
            item: container,
            id: settings.id
        })
        // Edit image
        div.addClass('masked-img' + settings.id);
        div.attr('data-id', settings.id);
        // ends
        return container;
    };
}(jQuery));

//Download image to server 

function test(){
var canvas  = document.getElementById("cvs");
var dataURL = canvas.toDataURL();

$.ajax({
  type: "POST",
  url: "upload.php",
  data: { 
     imgBase64: dataURL
  }
}).done(function(o) {
  console.log('saved'); 

});

}
.container {
	background: silver;
	position: relative;
}

.container img {
	position: absolute;
	top: 0;
	bottom: 250px;
	left: 0;
	right: 0;
	margin: auto;
	z-index: 999;
}

.masked-img {
	overflow: hidden;
	position: relative;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input id="fileup" name="fileup" type="file" style="display:none">
<div id="container" class="container">
</div>

        
<br/>		
<button onclick="test()">Save image to server</button>

这是Pastebin

中的代码

1 个答案:

答案 0 :(得分:1)

主要问题是这里需要一些服务器端语言...当然,您可以(ajax)对base64进行POST,但是服务器上的某些内容必须知道如何处理接收到的POST(ed)数据。

下面是我在上一个项目中使用的PHP(服务器端代码),允许用户上传自己的头像图像。

在我的用例中,我使用ajax POST发送3件事:

  1. 用户图像文件名
  2. 用户图像文件扩展名(png,jpg或gif)
  3. 原始base64编码数据

PHP应该是可以自我解释的,但是如果您有任何疑问,请告诉我。

您可能需要确保在写入映像的文件夹上的权限实际上将允许PHP进程进行写入。有时我不得不调整文件夹权限,仅取决于主机平台配置。

如果它不起作用,您可以将PHP Errors设置为ON,这样它将以有关PHP存在的问题的详细信息进行响应。 (快速的Google搜索应对此有所帮助。)

您可以使用一个已知的文件类型和文件名简化我的示例代码,以进行快速测试。如果您需要帮助,我也许可以通过电子邮件与您联系以获取详细信息和帮助。 (我记得当我处理这个问题时,我非常渴望让它工作-我感到您的痛苦!!!)

已更新了适用于该解决方案的PHP源代码:

if( isset($_POST['imgBase64']) && isset($_POST['imgFileName']) && 
isset($_POST['imgFileType']) ){

    $fname = filter_input(INPUT_POST, 'imgFileName'); // THE FILENAME THE USER CHOSE IS RECEIVED VIA POST
    $img = filter_input(INPUT_POST, 'imgBase64');  // THE BASE64 ENCODING RECEIVED VIA POST
    $imgtype = filter_input(INPUT_POST, 'imgFileType');  // THE FILE TYPE / EXTENSION IS RECEIVED VIA POST

    // STRIP OFF THE BEGINNING OF THE BASE64 DATA, BUT DEPENDS ON THE IMAGE TYPE.  
    // I COULD HAVE SIMPLIFIED THIS BUT USED IF STATEMENTS.
    if ( $imgtype === 'png'){
        $img = str_replace('data:image/png;base64,', '', $img);
    };
    if ( $imgtype === 'jpg' || $imgtype === 'jpeg'){
        $img = str_replace('data:image/jpeg;base64,', '', $img);
    };
    if ( $imgtype === 'gif'){
        $img = str_replace('data:image/gif;base64,', '', $img);
    };

    // REPLACE ALL SPACES IN THE IMAGE DATA WITH PLUS SYMBOL
    $img = str_replace(' ', '+', $img); 
    // CONVERT THE DATA FROM BASE64 ENCODING
    $img = base64_decode($img); 

    // SAVE THE FILE 
    file_put_contents('...path.../'.$fname, $img);


    echo '{"error":false, "message":"Image has been saved successfully!","data":[{"fileName": "'.$fname.'"}]}';
}