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using MyEpiSite.Business.Rendering;
using System;
using System.Configuration;
using System.Web;
using System.Web.Mvc;
namespace MyEpiSite.Helpers
{
public static class PictureHelper
{
public static IHtmlString Picture(this HtmlHelper helper, string imageUrl, ImageType imageType, string cssClass = "")
{
if (imageUrl == null)
{
return new MvcHtmlString(string.Empty);
}
//create picture element
var pictureElement = new TagBuilder("picture");
if (imageType.SrcSetWidths != null)
{
//if jpg, also add webp source element
if (imageUrl.EndsWith(".jpg"))
{
var webpSourceElement = GetSourceElement(imageUrl, imageType, "webp");
pictureElement.InnerHtml += webpSourceElement.ToString(TagRenderMode.SelfClosing);
}
//add source element to picture element
var sourceElement = GetSourceElement(imageUrl, imageType);
pictureElement.InnerHtml += sourceElement.ToString(TagRenderMode.SelfClosing);
}
//create img element
var imgElement = new TagBuilder("img");
imgElement.Attributes.Add("src", imageUrl + GetQueryString(imageType, imageType.DefaultImgWidth));
if (!string.IsNullOrEmpty(cssClass))
{
imgElement.Attributes.Add("class", cssClass);
}
//add img element to picture element
pictureElement.InnerHtml += imgElement.ToString(TagRenderMode.SelfClosing);
return new MvcHtmlString(pictureElement.ToString());
}
private static TagBuilder GetSourceElement(string imageUrl, ImageType imageType, string format = "")
{
var sourceElement = new TagBuilder("source");
if (!string.IsNullOrEmpty(format))
{
//add type attribute
sourceElement.Attributes.Add("type", "image/" + format);
}
//add srcset attribute
var srcset = string.Empty;
foreach (var width in imageType.SrcSetWidths)
{
srcset += imageUrl + GetQueryString(imageType, width, format) + " " + width + "w, ";
}
sourceElement.Attributes.Add("srcset", srcset);
//add sizes attribute
var sizes = string.Empty;
foreach (var size in imageType.SrcSetSizes)
{
sizes += size + ", ";
}
sourceElement.Attributes.Add("sizes", sizes);
return sourceElement;
}
private static string GetQueryString(ImageType imageType, int? imageWidth, string format = "")
{
var qs = "?";
if (!string.IsNullOrEmpty(format))
{
qs += $"format={format}&"; //format needs to be added before quality
}
qs += $"quality={imageType.Quality}&width={imageWidth}";
if (imageType.HeightRatio > 0)
{
qs += $"&mode=crop&heightratio={imageType.HeightRatio}";
}
bool.TryParse(ConfigurationManager.AppSettings["ImageProcessorDebug"], out var showDebugInfo);
if (showDebugInfo)
{
qs += GetInfoQueryString(imageType, imageWidth, format);
}
return qs;
}
private static string GetInfoQueryString(ImageType imageType, int? imageWidth, string format)
{
if (string.IsNullOrEmpty(format))
{
format = "origin";
}
var height = Convert.ToInt32(imageWidth * imageType.HeightRatio);
var watermark = $"format:%20{format}%20width:%20{imageWidth}" + (height > 0 ? $"%20height:%20{height}" : "");
var fontsize = imageWidth > 800 ? 35 : 17;
var textX = imageWidth / 2 - 150;
textX = textX < 0 ? 10 : textX;
return $"&watermark={watermark}&color=FF2D31&fontsize={fontsize}&textposition={textX},{Convert.ToInt32(height / 2)}";
}
}
}
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