[英]Display a selected image from upload in Shiny UI
我希望能够通过文件输入上传多个图像并显示在UI中选择的单个图像
用户界面
library(shiny)
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
fileInput("file","Upload the file", multiple = TRUE), # fileinput() function is used to get the file upload contorl option
uiOutput("selectfile")
),
mainPanel(
uiOutput('images')
)
)
)
服务器
server <- function(input,output) {
## Side bar select input widget coming through renderUI()
# Following code displays the select input widget with the list of file loaded by the user
output$selectfile <- renderUI({
if(is.null(input$file)) {return()}
list(hr(),
helpText("Select the files for which you need to see data and summary stats"),
selectInput("Select", "Select", choices=input$file$name)
)
})
output$images <- renderImage({
if(is.null(input$file)) {return(NULL)}
for (i in 1:nrow(input$file))
{
if(input$file$name[i] == input$Select){
list(src=input$file$datapath[i],
alt= "error")
print(input$file$name[i])
print(input$file$datapath[i])
}
}
})
}
使用此解决方案,数据路径和名称的打印为我显示了正确的答案,但是在尝试渲染图像后,我仍然遇到相同的错误:“警告:基本名称错误:预期为字符向量参数”。
这是使用base64编码的解决方案。
library(shiny)
library(base64enc)
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
fileInput("file", "Upload the file", multiple = TRUE),
uiOutput("selectfile")
),
mainPanel(
uiOutput('image')
)
)
)
server <- function(input,output) {
output$selectfile <- renderUI({
req(input$file)
list(hr(),
helpText("Select the files for which you need to see data and summary stats"),
selectInput("Select", "Select", choices=input$file$name)
)
})
output$image <- renderUI({
req(input$Select)
i <- which(input$file$name == input$Select)
if(length(i)){
base64 <- dataURI(file = input$file$datapath[i], mime = input$file$type[i])
tags$img(src = base64, alt= "error")
}
})
}
shinyApp(ui, server)
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