render Image not outputting Shiny - shiny

Question

output$plot <- renderImage({
outfile <- tempfile(fileext = '.png')
png(outfile, width = 400, height = 300)
venn.diagram(
x = list(
T = T,
I = I
),
main = "Venn Diagram ",
filename =outfile, output=TRUE,
lwd = 2,na = "remove",
fill = c("orange", "blue"),
alpha = c(0.5,0.5),
label.col = "black",
cex=1.5,
fontface = "plain",
cat.col = c("cornflowerblue", "pink"),
cat.cex = 1.5,
cat.fontfamily = "serif",
cat.fontface = "plain",
cat.dist = c(0.05, 0.05),
cat.pos = c(-20, 14),
cat.default.pos = "text",
scaled = FALSE
)
dev.off()
list(src = outfile,
contentType = 'image/png',
width = 400,
height = 300,
alt = "This is alternate text")
}, deleteFile = TRUE)
I was trying plot a venn diagram using this code. But it only displays This is alternate text and not outputting any image on the app, Any Idea ?

Answer 1

Try to create a reactive graph as shown below
output$plot <- renderImage({
vennd <- reactive({venn.diagram(
x = list(
T = T,
I = I
),
main = "Venn Diagram ",
filename =outfile, output=TRUE,
lwd = 2,na = "remove",
fill = c("orange", "blue"),
alpha = c(0.5,0.5),
label.col = "black",
cex=1.5,
fontface = "plain",
cat.col = c("cornflowerblue", "pink"),
cat.cex = 1.5,
cat.fontfamily = "serif",
cat.fontface = "plain",
cat.dist = c(0.05, 0.05),
cat.pos = c(-20, 14),
cat.default.pos = "text",
scaled = FALSE
)
})
outfile <- tempfile(fileext = '.png')
png(outfile, width = 400, height = 300)
vennd()
dev.off()
list(src = outfile,
contentType = 'image/png',
width = 400,
height = 300,
alt = "This is alternate text")
}, deleteFile = TRUE)

Answer 2

output$plot <- renderImage({
vennd <- reactive({venn.diagram(
x = list(
T = T,
I = I
),
main = "",
filename =outfile, output=TRUE,
lwd = 2,na = "remove",imagetype="png",
fill = c("orange", "blue"),
alpha = c(0.5,0.5),
label.col = "black",
cex=1.5,
fontface = "plain",
cat.col = c("cornflowerblue", "pink"),
cat.cex = 1.5,
cat.fontfamily = "serif",
cat.fontface = "plain",
cat.dist = c(0.05, 0.05),
cat.pos = c(-20, 14),
cat.default.pos = "text",
scaled = FALSE
)
})
outfile <- tempfile(fileext = '.png')
png(outfile, width = 500, height = 500,type="cairo")
vennd()
dev.off()
list(src = outfile,
contentType = 'image/png',
width = 500,
height = 500,
alt = "This is alternate text")
}, deleteFile = TRUE)
Need to add imagetype="png" and type="cairo" thank you #YBS