clean up tbl.R, add method for creating a dummy tbl from a tibble

DESCRIPTION

@@ -13,7 +13,10 @@ License: MIT + file LICENSE
 VignetteBuilder: knitr
 Depends: 
     R (>= 3.3)
-Imports: 
+Imports:
+    assertthat,
+    DBI (>= 0.3.0),
+    methods,
     utils,
     httr (>= 1.3),
     jsonlite,
@@ -23,9 +26,11 @@ Imports:
     rappdirs,
     dbplyr,
     dplyr,
+    purrr,
     tidyselect (>= 0.2.4)
 Suggests:
     knitr,
+    DBItest,
     testthat
 Roxygen: list(markdown=TRUE)
 RoxygenNote: 6.1.0.9000

R/#AzureDataExplorer.R#

@@ -1,16 +0,0 @@
-.onLoad <- function(libname, pkgname)
-{
-    config_dir <- config_dir()
-    if(!dir.exists(config_dir))
-        dir.create(config_dir, recursive=TRUE)
-
-    add_methods()
-    invisible(NULL)
-}
-
-
-config_dir <- function()
-{
-    rappdirs::user_config_dir(appname="AzureDataExplorer", appauthor="AzureR", roaming=FALSE)
-}
-c

R/#az_kusto.R#

@@ -1,12 +0,0 @@
-#' @export
-az_data_explorer <- R6::R6Class("az_data_explorer", inherit=AzureRMR::az_resource,
-                                public=list(
-    get_ade_cluster=function(tenant=NULL)
-    {
-        clus_name <- sub(".kusto.windows.net$", "", httr::parse_url(self$properties$queryUri)$host)
-        if(is.null(tenant))
-            tenant <- self$properties$trustedExternalTenants[[1]]$value
-        ade_cluster(clus_name, tenant=tenant)
-    }
-))
-

R/.#az_kusto.R

@@ -1 +0,0 @@
-alex@alex-XPS-13-9343.5633:1506128837

R/dbi.R

@@ -0,0 +1,88 @@
+#' Driver for Azure Data Explorer
+#'
+#' @keywords internal
+#' @export
+#' @import DBI
+#' @import methods
+setClass("AzureDataExplorerDriver", contains = "DBIDriver")
+
+#' @export
+#' @rdname AzureDataExplorer-class
+setMethod("dbUnloadDriver", "AzureDataExplorerDriver", function(drv, ...)
+{
+    TRUE
+})
+
+setMethod("show", "AzureDataExplorerDriver", function(object){
+    cat("<AzureDataExplorerDriver>\n")
+})
+
+AzureDataExplorer <- function()
+{
+    new("AzureDataExplorerDriver")
+}
+
+#' AzureDataExplorer connection class.
+#'
+#' @export
+#' @keywords internal
+setClass("AzureDataExplorerConnection",
+         contains = "DBIConnection",
+         slots = list(
+             host = "character",
+             ptr = "externalptr"
+         ))
+
+#' @param drv An object created by AzureDataExplorer
+#' @rdname AzureDataExplorer
+#' @export
+#' @examples
+#' \dontrun{
+#' db <- dbConnect(AzureDataExplorer::AzureDataExplorer())
+#' dbWriteTable(db, "mtcars", mtcars)
+#' dbGetQuery(db, "mtcars | where cyl == 4")
+#' }
+setMethod("dbConnect", "AzureDataExplorerDriver", function(drv, ...)
+{
+    new("AzureDataExplorerConnection", host=host, ...)
+})
+
+#' AzureDataExplorer results class
+#'
+#' @keywords internal
+#' @export
+setClass("AzureDataExplorerResult",
+         contains="DBIResult",
+         slots = list(ptr = "externalptr")
+         )
+
+#' Send a query to AzureDataExplorer.
+#'
+#' @export
+#' @examples
+#'
+setMethod("dbSendQuery", "AzureDataExplorerConnection", function(conn, statement, ...)
+{
+    # TODO
+    new("AzureDataExplorerResult", ...)
+})
+
+#' @export
+setMethod("dbClearResult", "AzureDataExplorerResult", function(res, ...)
+{
+    # TODO: free resources
+    TRUE
+})
+
+#' Retrieve records from query
+#' @export
+setMethod("dbFetch", "AzureDataExplorerResult", function(res, n = -1, ...)
+{
+    #TODO
+})
+
+#' @export
+setMethod("dbHasCompleted", "AzureDataExplorerResult", function(res, ...)
+{
+    #TODO
+})

R/tbl.R

@@ -4,90 +4,32 @@ tbl <- function(object, ...)
     UseMethod("tbl")
 }
 
-new_tbl <- function(data) {
-  structure(data, class = "tbl")
-}
-
-
-#' @export
-tbl.ade_database <- function(object, table, ...)
+tbl_ade <- function(object, table, ...)
 {
-    out <- list(tbl=table, db=object)
-    class(out) <- "tbl"
-    out
+    ops <- list(x = table, vars = names(table))
+    dplyr::make_tbl("ade", db = object, ops = ops)
 }
 
-
-
-#' @export
-select.tbl <- function(.data, ...)
+#' Create a dummy tbl from a data frame.
+#' Useful for testing KQL generation without a remote connection.
+tbl.tbl_df <- function(table, object=simulate_ade())
 {
-    dots <- quos(...)
-    add_op_single("select", .data, dots = dots)
-    ## grps <- group_vars(.data)
-    ## vars <- unique(c(grps, select_vars(names(.data), ...)))
-    ## if(length(vars) == 0)
-    ##     stop("No variables selected", call.=FALSE)
-
-    ## arglst <- list(.data, varsToKeep=vars)
-    ## arglst <- doExtraArgs(arglst, .data, enexpr(.rxArgs), .outFile)
-
-    ## on.exit(deleteIfTbl(.data))
-    ## # need to use rxImport on non-Xdf data sources because of bugs in rxDataStep (?)
-    ## output <- callRx("rxDataStep", arglst)
-    ## simpleRegroup(output, grps)
-}
-
-
-#' @export
-add_op_single <- function(name, .data, dots = list(), args = list()) {
-  .data$ops <- op_single(name, x = .data$ops, dots = dots, args = args)
-  .data
+    tbl_ade(object, table)
 }
 
 #' @export
-op_single <- function(name, x, dots = list(), args = list()) {
+tbl.ade_database_endpoint <- function(object, table, ...)
+{
+    tbl_ade(object, table)
+}
+
+simulate_ade <- function()
+{
   structure(
-    list(
-      name = name,
-      x = x,
-      dots = dots,
-      args = args
-    ),
-    class = c(paste0("op_", name), "op_single", "op")
+      list(
+          db = "local_df",
+          cluster = "local_df"
+      ),
+    class = "ade_database_endpoint"
   )
 }
-
-#' @export
-show_query.tbl <- function(x, ...){
-    qry <- kql_build(x, con=x$src, ...)
-    kql_render(qry, con = x$src, ...)
-}
-
-#' @export
-kql_render <- function(query, con = NULL, ...)
-{
-    UseMethod("kql_render")
-}
-
-#' @export
-kql_render.tbl <- function(query, con = query$con, ...)
-{
-    q <- kql_build(query$ops, con = con, ...)
-}
-
-#' @export
-kql_build <- function(op, con = NULL, ...) {
-    UseMethod("kql_build")
-}
-
-#' @export
-kql_build.tbl <- function(op, con = NULL, ...){
-    q <- kql_build(op$ops, con = con, ...)
-}
-
-#' @export
-sql_build.op_select <- function(op, con, ...) {
-  vars <- tidyselect::vars_select(op_vars(op$x), !!! op$dots, .include = op_grps(op$x))
-  select_query(sql_build(op$x, con), ident(vars))
-}