selectinput in Shiny R

Question

I can not get the value of select input, I need to generate a cloud of words, but the content of the cloud will depend on the selected option.

The application is loading infinitely. Help me please.

UI.R

fluidPage(
# Application title
titlePanel("Word Cloud"),

sidebarLayout(
# Sidebar with a slider and selection inputs
sidebarPanel(
  selectInput("selection", "Choose a book:",
              choices = c(coletor1,coletor2),
        selected = coletor1),
  actionButton("update", "Change"),
  hr(),
  sliderInput("freq",
              "Minimum Frequency:",
              min = 1,  max = 1000, value = 1),
  sliderInput("max",
              "Maximum Number of Words:",
              min = 1,  max = 100,  value = 100)
),

# Show Word Cloud
mainPanel(
 tabsetPanel(type = "tabs", 
     tabPanel("Plot", plotOutput("plot"))

)

) ) )

Server.R

function(input, output, session) {

# Define a reactive expression for the document term matrix
terms <- reactive({
# Change when the "update" button is pressed...
input$update
# ...but not for anything else
isolate({
  withProgress({
    setProgress(message = "Processing corpus...")
    getTermMatrix(input$selection)
  })
})
})

# Make the wordcloud drawing predictable during a session
wordcloud_rep <- repeatable(wordcloud)

output$plot <- renderPlot({
v <- terms()
wordcloud_rep(names(v), v, scale=c(4,0.5),
              min.freq = input$freq, max.words=input$max,
              colors=brewer.pal(8, "Dark2"))
})
}

Global.R

library(tm)
library(wordcloud)
library(memoise)

library(RPostgreSQL)
con <- dbConnect(PostgreSQL(), user="postgres",      password="123456",dbname="postgres")
coletor1=dbGetQuery(con,"SELECT REPLACE(aux_coletprinc,' ','')          aux_coletprinc  from jabot.detacesso2 where aux_coletprinc ilike '%forz%a%'
")
coletor2=dbGetQuery(con,"SELECT REPLACE(aux_coletprinc,' ','')   aux_coletprinc  from jabot.detacesso2 where aux_coletprinc ilike '%vian%a%'
")

dbDisconnect(con)
list<-c(coletor1,coletor2) 

# Using "memoise" to automatically cache the results
getTermMatrix <- memoise(function(list) {

text <- list

myCorpus = Corpus(VectorSource(text))
myCorpus = tm_map(myCorpus, content_transformer(tolower))

myDTM = TermDocumentMatrix(myCorpus,
          control = list(minWordLength = 1))

m = as.matrix(myDTM)

sort(rowSums(m), decreasing = TRUE)
})

Answer 1

global.R runs before server.R and ui.R . Because of this, there is no input$selection yet.

You just have to define the getTermMatrix function in global.R . There is no need to define a nor the text that is going to be read.

You can do both in server.R , where the input list already exists. Altough, take a better look into your getTermMatrix() function, the book argument is never used.