geposanui/server.R

library(data.table)
library(DT)
library(gprofiler2)
library(plotly)
library(rclipboard)
library(shiny)

source("init.R")
source("scatter_plot.R")

#' Java script function to replace gene IDs with Ensembl gene links.
js_link <- JS("function(row, data) {
    let id = data[1];
    var name = data[2];
    if (!name) name = 'Unknown';
    let url = `https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=${id}`;
    $('td:eq(1)', row).html(`<a href=\"${url}\" target=\"_blank\">${name}</a>`);
}")

server <- function(input, output) {
    #' Show the customized slider for setting the required number of species.
    output$n_species_slider <- renderUI({
        sliderInput(
            "n_species",
            "Required number of species per gene",
            min = 0,
            max = if (input$species == "all") {
                nrow(species)
            } else {
                length(species_ids_replicative)
            },
            step = 1,
            value = 10
        )
    })

    #' This reactive expression applies all user defined filters as well as the
    #' desired ranking weights to the results.
    results <- reactive({
        # Select the species preset.

        results <- if (input$species == "all") {
            results_all
        } else {
            results_replicative
        }

        # Compute scoring factors and the weighted score.

        total_weight <- 0.0
        results[, score := 0.0]

        for (method in methods) {
            weight <- input[[method$id]]
            total_weight <- total_weight + weight
            column <- method$id
            weighted <- weight * results[, ..column]
            results[, score := score + weighted]
        }

        results[, score := score / total_weight]

        # Exclude genes with too few species.
        results <- results[n_species >= input$n_species]

        # Penalize missing species.
        if (input$penalize) {
            species_count <- if (input$species == "all") {
                nrow(species)
            } else {
                length(species_ids_replicative)
            }

            results <- results[, score := score * n_species / species_count]
        }

        # Apply the cut-off score.
        results <- results[score >= input$cutoff / 100]

        # Order the results based on their score.

        setorder(results, -score, na.last = TRUE)
        results[, rank := .I]
    })

    output$genes <- renderDT({
        method_ids <- sapply(methods, function(method) method$id)
        method_names <- sapply(methods, function(method) method$name)
        columns <- c("rank", "gene", "name", "chromosome", method_ids, "score")
        column_names <- c("", "Gene", "", "Chromosome", method_names, "Score")

        dt <- datatable(
            results()[, ..columns],
            rownames = FALSE,
            colnames = column_names,
            style = "bootstrap",
            extensions = "Scroller",
            options = list(
                rowCallback = js_link,
                columnDefs = list(list(visible = FALSE, targets = 2)),
                deferRender = TRUE,
                scrollY = 200,
                scroller = TRUE
            )
        )

        formatPercentage(dt, c(method_ids, "score"), digits = 1)
    })

    output$synposis <- renderText({
        results <- results()

        sprintf(
            "Found %i candidates including %i/%i verified and %i/%i suggested \
            TPE-OLD genes.",
            results[, .N],
            results[verified == TRUE, .N],
            genes[verified == TRUE, .N],
            results[suggested == TRUE, .N],
            genes[suggested == TRUE, .N]
        )
    })

    output$copy <- renderUI({
        results <- results()

        gene_ids <- results[, gene]
        names <- results[name != "", name]

        genes_text <- paste(gene_ids, collapse = "\n")
        names_text <- paste(names, collapse = "\n")

        splitLayout(
            rclipButton(
                "copy_ids_button",
                "Copy gene IDs",
                genes_text,
                icon = icon("clipboard"),
                width = "100%"
            ),
            rclipButton(
                "copy_names_button",
                "Copy gene names",
                names_text,
                icon = icon("clipboard"),
                width = "100%"
            )
        )
    })

    output$scatter <- renderPlotly({
        results <- results()

        gene_ids <- results[input$genes_rows_selected, gene]
        genes <- genes[id %chin% gene_ids]

        species <- if (input$species == "all") {
            species
        } else {
            species[replicative == TRUE]
        }

        scatter_plot(results, species, genes, distances)
    })

    output$gost <- renderPlotly({
        if (input$enable_gost) {
            result <- gost(results()[, gene], ordered_query = TRUE)
            gostplot(result, capped = FALSE, interactive = TRUE)
        } else {
            NULL
        }
    })
}