Detect how to display pdf files

Closes: #1099

modules/restserver/src/main/templates/index.html

@@ -43,8 +43,21 @@
              // this is required for transitioning; elm fails to parse the account
              account["requireSecondFactor"] = false;
          }
+
+         // hack to guess if the browser can display PDFs natively. It
+         // seems that almost all browsers allow to query the
+         // navigator.mimeTypes array, except firefox.
+         var ua = navigator.userAgent.toLowerCase();
+         var pdfSupported = false;
+         if (ua.indexOf("firefox") > -1) {
+             pdfSupported = ua.indexOf("mobile") == -1;
+         } else {
+             pdfSupported = "application/pdf" in navigator.mimeTypes;
+         }
+
          var elmFlags = {
              "account": account,
+             "pdfSupported": pdfSupported,
              "config": {{{flagsJson}}}
          };
         </script>

modules/webapp/src/main/elm/Comp/ItemCard.elm

@@ -22,6 +22,7 @@ import Api.Model.ItemLight exposing (ItemLight)
 import Comp.LinkTarget exposing (LinkTarget(..))
 import Data.Direction
 import Data.Fields
+import Data.Flags exposing (Flags)
 import Data.Icons as Icons
 import Data.ItemSelection exposing (ItemSelection)
 import Data.ItemTemplate as IT
@@ -150,8 +151,8 @@ update ddm msg model =
 --- View2
 
 
-view2 : Texts -> ViewConfig -> UiSettings -> Model -> ItemLight -> Html Msg
-view2 texts cfg settings model item =
+view2 : Texts -> ViewConfig -> UiSettings -> Flags -> Model -> ItemLight -> Html Msg
+view2 texts cfg settings flags model item =
     let
         isCreated =
             item.state == "created"
@@ -221,7 +222,7 @@ view2 texts cfg settings model item =
                , metaDataContent2 texts settings item
                , notesContent2 settings item
                , fulltextResultsContent2 item
-               , previewMenu2 texts settings cfg model item (currentAttachment model item)
+               , previewMenu2 texts settings flags cfg model item (currentAttachment model item)
                , selectedDimmer
                ]
         )
@@ -475,8 +476,8 @@ previewImage2 cfg settings cardAction model item =
         ]
 
 
-previewMenu2 : Texts -> UiSettings -> ViewConfig -> Model -> ItemLight -> Maybe AttachmentLight -> Html Msg
-previewMenu2 texts settings cfg model item mainAttach =
+previewMenu2 : Texts -> UiSettings -> Flags -> ViewConfig -> Model -> ItemLight -> Maybe AttachmentLight -> Html Msg
+previewMenu2 texts settings flags cfg model item mainAttach =
     let
         pageCount =
             Maybe.andThen .pageCount mainAttach
@@ -489,11 +490,7 @@ previewMenu2 texts settings cfg model item mainAttach =
             Data.UiSettings.fieldHidden settings f
 
         mkAttachUrl attach =
-            if settings.nativePdfPreview then
-                cfg.attachUrl attach
-
-            else
-                cfg.attachUrl attach ++ "/view"
+            Data.UiSettings.pdfUrl settings flags (cfg.attachUrl attach)
 
         attachUrl =
             Maybe.map mkAttachUrl mainAttach

modules/webapp/src/main/elm/Comp/ItemCardList.elm

@@ -169,19 +169,19 @@ type alias ViewConfig =
     }
 
 
-view2 : Texts -> ViewConfig -> UiSettings -> Model -> Html Msg
-view2 texts cfg settings model =
+view2 : Texts -> ViewConfig -> UiSettings -> Flags -> Model -> Html Msg
+view2 texts cfg settings flags model =
     div
         [ classList
             [ ( "ds-item-list", True )
             , ( "ds-multi-select-mode", isMultiSelectMode cfg )
             ]
         ]
-        (List.map (viewGroup2 texts model cfg settings) model.results.groups)
+        (List.map (viewGroup2 texts model cfg settings flags) model.results.groups)
 
 
-viewGroup2 : Texts -> Model -> ViewConfig -> UiSettings -> ItemLightGroup -> Html Msg
-viewGroup2 texts model cfg settings group =
+viewGroup2 : Texts -> Model -> ViewConfig -> UiSettings -> Flags -> ItemLightGroup -> Html Msg
+viewGroup2 texts model cfg settings flags group =
     div [ class "ds-item-group" ]
         [ div
             [ class "flex py-1 mt-2 mb-2 flex flex-row items-center"
@@ -206,12 +206,12 @@ viewGroup2 texts model cfg settings group =
                 []
             ]
         , div [ class "grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 2xl:grid-cols-4 gap-2" ]
-            (List.map (viewItem2 texts model cfg settings) group.items)
+            (List.map (viewItem2 texts model cfg settings flags) group.items)
         ]
 
 
-viewItem2 : Texts -> Model -> ViewConfig -> UiSettings -> ItemLight -> Html Msg
-viewItem2 texts model cfg settings item =
+viewItem2 : Texts -> Model -> ViewConfig -> UiSettings -> Flags -> ItemLight -> Html Msg
+viewItem2 texts model cfg settings flags item =
     let
         currentClass =
             if cfg.current == Just item.id then
@@ -228,7 +228,7 @@ viewItem2 texts model cfg settings item =
                 |> Maybe.withDefault Comp.ItemCard.init
 
         cardHtml =
-            Comp.ItemCard.view2 texts.itemCard vvcfg settings cardModel item
+            Comp.ItemCard.view2 texts.itemCard vvcfg settings flags cardModel item
     in
     Html.map (ItemCardMsg item) cardHtml
 

modules/webapp/src/main/elm/Comp/ItemDetail/Model.elm

@@ -100,7 +100,6 @@ type alias Model =
     , sentMailsOpen : Bool
     , attachMeta : Dict String Comp.AttachmentMeta.Model
     , attachMetaOpen : Bool
-    , pdfNativeView : Maybe Bool
     , attachModal : Maybe ConfirmModalValue
     , addFilesOpen : Bool
     , addFilesModel : Comp.Dropzone.Model
@@ -236,7 +235,6 @@ emptyModel =
     , sentMailsOpen = False
     , attachMeta = Dict.empty
     , attachMetaOpen = False
-    , pdfNativeView = Nothing
     , attachModal = Nothing
     , addFilesOpen = False
     , addFilesModel = Comp.Dropzone.init []
@@ -316,7 +314,6 @@ type Msg
     | SentMailsResp (Result Http.Error SentMails)
     | AttachMetaClick String
     | AttachMetaMsg String Comp.AttachmentMeta.Msg
-    | TogglePdfNativeView Bool
     | RequestDeleteAttachment String
     | DeleteAttachConfirmed String
     | RequestDeleteSelected

modules/webapp/src/main/elm/Comp/ItemDetail/SingleAttachment.elm

@@ -85,12 +85,8 @@ view texts flags settings model pos attach =
                 , style "max-height" "calc(100vh - 140px)"
                 , style "min-height" "500px"
                 ]
-                [ iframe
-                    [ if Maybe.withDefault settings.nativePdfPreview model.pdfNativeView then
-                        src fileUrl
-
-                      else
-                        src (fileUrl ++ "/view")
+                [ embed
+                    [ src <| Data.UiSettings.pdfUrl settings flags fileUrl
                     , class "absolute h-full w-full top-0 left-0 mx-0 py-0"
                     , id "ds-pdf-view-iframe"
                     ]
@@ -254,18 +250,6 @@ attachHeader texts settings model _ attach =
                                 , classList [ ( "hidden", not attach.converted ) ]
                                 ]
                           }
-                        , { icon =
-                                if Maybe.withDefault settings.nativePdfPreview model.pdfNativeView then
-                                    "fa fa-toggle-on"
-
-                                else
-                                    "fa fa-toggle-off"
-                          , label = texts.renderPdfByBrowser
-                          , attrs =
-                                [ onClick (TogglePdfNativeView settings.nativePdfPreview)
-                                , href "#"
-                                ]
-                          }
                         , { icon =
                                 if isAttachMetaOpen model attach.id then
                                     "fa fa-toggle-on"

modules/webapp/src/main/elm/Comp/ItemDetail/Update.elm

@@ -913,19 +913,6 @@ update key flags inav settings msg model =
                 Nothing ->
                     resultModel model
 
-        TogglePdfNativeView default ->
-            resultModel
-                { model
-                    | pdfNativeView =
-                        case model.pdfNativeView of
-                            Just flag ->
-                                Just (not flag)
-
-                            Nothing ->
-                                Just (not default)
-                    , attachmentDropdownOpen = False
-                }
-
         DeleteAttachConfirmed attachId ->
             let
                 cmd =

modules/webapp/src/main/elm/Comp/UiSettingsForm.elm

@@ -28,6 +28,7 @@ import Data.DropdownStyle as DS
 import Data.Fields exposing (Field)
 import Data.Flags exposing (Flags)
 import Data.ItemTemplate as IT exposing (ItemTemplate)
+import Data.Pdf exposing (PdfMode)
 import Data.TagOrder
 import Data.UiSettings exposing (ItemPattern, Pos(..), UiSettings)
 import Dict exposing (Dict)
@@ -50,7 +51,8 @@ type alias Model =
     , searchPageSizeModel : Comp.IntField.Model
     , tagColors : Dict String Color
     , tagColorModel : Comp.ColorTagger.Model
-    , nativePdfPreview : Bool
+    , pdfMode : PdfMode
+    , pdfModeModel : Comp.FixedDropdown.Model PdfMode
     , itemSearchNoteLength : Maybe Int
     , searchNoteLengthModel : Comp.IntField.Model
     , searchMenuFolderCount : Maybe Int
@@ -122,7 +124,8 @@ init flags settings =
             Comp.ColorTagger.init
                 []
                 Data.Color.all
-      , nativePdfPreview = settings.nativePdfPreview
+      , pdfMode = settings.pdfMode
+      , pdfModeModel = Comp.FixedDropdown.init Data.Pdf.allModes
       , itemSearchNoteLength = Just settings.itemSearchNoteLength
       , searchNoteLengthModel =
             Comp.IntField.init
@@ -169,7 +172,6 @@ type Msg
     = SearchPageSizeMsg Comp.IntField.Msg
     | TagColorMsg Comp.ColorTagger.Msg
     | GetTagsResp (Result Http.Error TagList)
-    | TogglePdfPreview
     | NoteLengthMsg Comp.IntField.Msg
     | SearchMenuFolderMsg Comp.IntField.Msg
     | SearchMenuTagMsg Comp.IntField.Msg
@@ -185,6 +187,7 @@ type Msg
     | ToggleSideMenuVisible
     | TogglePowerSearch
     | UiLangMsg (Comp.FixedDropdown.Msg UiLanguage)
+    | PdfModeMsg (Comp.FixedDropdown.Msg PdfMode)
 
 
 
@@ -290,15 +293,6 @@ update sett msg model =
             in
             ( model_, nextSettings )
 
-        TogglePdfPreview ->
-            let
-                flag =
-                    not model.nativePdfPreview
-            in
-            ( { model | nativePdfPreview = flag }
-            , Just { sett | nativePdfPreview = flag }
-            )
-
         GetTagsResp (Ok tl) ->
             let
                 categories =
@@ -463,6 +457,22 @@ update sett msg model =
                 Just { sett | uiLang = newLang }
             )
 
+        PdfModeMsg lm ->
+            let
+                ( m, sel ) =
+                    Comp.FixedDropdown.update lm model.pdfModeModel
+
+                newMode =
+                    Maybe.withDefault model.pdfMode sel
+            in
+            ( { model | pdfModeModel = m, pdfMode = newMode }
+            , if newMode == model.pdfMode then
+                Nothing
+
+              else
+                Just { sett | pdfMode = newMode }
+            )
+
 
 
 --- View2
@@ -516,6 +526,13 @@ settingFormTabs texts flags _ model =
             , style = DS.mainStyle
             , selectPlaceholder = texts.basics.selectPlaceholder
             }
+
+        pdfModeCfg =
+            { display = texts.pdfMode
+            , icon = \_ -> Nothing
+            , style = DS.mainStyle
+            , selectPlaceholder = texts.basics.selectPlaceholder
+            }
     in
     [ { name = "general"
       , title = texts.general
@@ -689,13 +706,14 @@ settingFormTabs texts flags _ model =
       , info = Nothing
       , body =
             [ div [ class "mb-4" ]
-                [ MB.viewItem <|
-                    MB.Checkbox
-                        { tagger = \_ -> TogglePdfPreview
-                        , label = texts.browserNativePdfView
-                        , value = model.nativePdfPreview
-                        , id = "uisetting-pdfpreview-toggle"
-                        }
+                [ label [ class S.inputLabel ] [ text texts.browserNativePdfView ]
+                , Html.map PdfModeMsg
+                    (Comp.FixedDropdown.viewStyled2
+                        pdfModeCfg
+                        False
+                        (Just model.pdfMode)
+                        model.pdfModeModel
+                    )
                 ]
             , div [ class "mb-4" ]
                 [ MB.viewItem <|

modules/webapp/src/main/elm/Data/Flags.elm

@@ -41,6 +41,7 @@ type alias Config =
 
 type alias Flags =
     { account : Maybe AuthResult
+    , pdfSupported : Bool
     , config : Config
     }
 

modules/webapp/src/main/elm/Data/Pdf.elm

@@ -0,0 +1,67 @@
+module Data.Pdf exposing (PdfMode(..), allModes, asString, detectUrl, fromString, serverUrl)
+
+{-| Makes use of the fact, that docspell uses a `/view` suffix on the
+path to provide a browser independent PDF view.
+-}
+
+import Data.Flags exposing (Flags)
+import Html exposing (..)
+import Html.Attributes exposing (..)
+
+
+type PdfMode
+    = Detect
+    | Native
+    | Server
+
+
+allModes : List PdfMode
+allModes =
+    [ Detect, Native, Server ]
+
+
+asString : PdfMode -> String
+asString mode =
+    case mode of
+        Detect ->
+            "detect"
+
+        Native ->
+            "native"
+
+        Server ->
+            "server"
+
+
+fromString : String -> Maybe PdfMode
+fromString str =
+    case String.toLower str of
+        "detect" ->
+            Just Detect
+
+        "native" ->
+            Just Native
+
+        "server" ->
+            Just Server
+
+        _ ->
+            Nothing
+
+
+serverUrl : String -> String
+serverUrl url =
+    if String.endsWith "/" url then
+        url ++ "view"
+
+    else
+        url ++ "/view"
+
+
+detectUrl : Flags -> String -> String
+detectUrl flags url =
+    if flags.pdfSupported then
+        url
+
+    else
+        serverUrl url

modules/webapp/src/main/elm/Data/UiSettings.elm

@@ -20,6 +20,7 @@ module Data.UiSettings exposing
     , fieldVisible
     , merge
     , mergeDefaults
+    , pdfUrl
     , posFromString
     , posToString
     , storedUiSettingsDecoder
@@ -34,7 +35,9 @@ import Api.Model.Tag exposing (Tag)
 import Data.BasicSize exposing (BasicSize)
 import Data.Color exposing (Color)
 import Data.Fields exposing (Field)
+import Data.Flags exposing (Flags)
 import Data.ItemTemplate exposing (ItemTemplate)
+import Data.Pdf exposing (PdfMode)
 import Data.UiTheme exposing (UiTheme)
 import Dict exposing (Dict)
 import Html exposing (Attribute)
@@ -57,7 +60,7 @@ force default settings.
 type alias StoredUiSettings =
     { itemSearchPageSize : Maybe Int
     , tagCategoryColors : List ( String, String )
-    , nativePdfPreview : Bool
+    , pdfMode : Maybe String
     , itemSearchNoteLength : Maybe Int
     , itemDetailNotesPosition : Maybe String
     , searchMenuFolderCount : Maybe Int
@@ -91,7 +94,7 @@ storedUiSettingsDecoder =
     Decode.succeed StoredUiSettings
         |> P.optional "itemSearchPageSize" maybeInt Nothing
         |> P.optional "tagCategoryColors" (Decode.keyValuePairs Decode.string) []
-        |> P.optional "nativePdfPreview" Decode.bool False
+        |> P.optional "pdfMode" maybeString Nothing
         |> P.optional "itemSearchNoteLength" maybeInt Nothing
         |> P.optional "itemDetailNotesPosition" maybeString Nothing
         |> P.optional "searchMenuFolderCount" maybeInt Nothing
@@ -121,7 +124,7 @@ storedUiSettingsEncode value =
     Encode.object
         [ ( "itemSearchPageSize", maybeEnc Encode.int value.itemSearchPageSize )
         , ( "tagCategoryColors", Encode.dict identity Encode.string (Dict.fromList value.tagCategoryColors) )
-        , ( "nativePdfPreview", Encode.bool value.nativePdfPreview )
+        , ( "pdfMode", maybeEnc Encode.string value.pdfMode )
         , ( "itemSearchNoteLength", maybeEnc Encode.int value.itemSearchNoteLength )
         , ( "itemDetailNotesPosition", maybeEnc Encode.string value.itemDetailNotesPosition )
         , ( "searchMenuFolderCount", maybeEnc Encode.int value.searchMenuFolderCount )
@@ -146,14 +149,15 @@ storedUiSettingsEncode value =
 {-| Settings for the web ui. These fields are all mandatory, since
 there is always a default value.
 
-When loaded from local storage, all optional fields can fallback to a
-default value, converting the StoredUiSettings into a UiSettings.
+When loaded from local storage or the server, all optional fields can
+fallback to a default value, converting the StoredUiSettings into a
+UiSettings.
 
 -}
 type alias UiSettings =
     { itemSearchPageSize : Int
     , tagCategoryColors : Dict String Color
-    , nativePdfPreview : Bool
+    , pdfMode : PdfMode
     , itemSearchNoteLength : Int
     , itemDetailNotesPosition : Pos
     , searchMenuFolderCount : Int
@@ -219,7 +223,7 @@ defaults : UiSettings
 defaults =
     { itemSearchPageSize = 60
     , tagCategoryColors = Dict.empty
-    , nativePdfPreview = False
+    , pdfMode = Data.Pdf.Detect
     , itemSearchNoteLength = 0
     , itemDetailNotesPosition = Bottom
     , searchMenuFolderCount = 3
@@ -259,7 +263,10 @@ merge given fallback =
                 |> Dict.map (\_ -> Maybe.withDefault Data.Color.Grey)
             )
             fallback.tagCategoryColors
-    , nativePdfPreview = given.nativePdfPreview
+    , pdfMode =
+        given.pdfMode
+            |> Maybe.andThen Data.Pdf.fromString
+            |> Maybe.withDefault fallback.pdfMode
     , itemSearchNoteLength =
         choose given.itemSearchNoteLength fallback.itemSearchNoteLength
     , itemDetailNotesPosition =
@@ -313,7 +320,7 @@ toStoredUiSettings settings =
     , tagCategoryColors =
         Dict.map (\_ -> Data.Color.toString) settings.tagCategoryColors
             |> Dict.toList
-    , nativePdfPreview = settings.nativePdfPreview
+    , pdfMode = Just (Data.Pdf.asString settings.pdfMode)
     , itemSearchNoteLength = Just settings.itemSearchNoteLength
     , itemDetailNotesPosition = Just (posToString settings.itemDetailNotesPosition)
     , searchMenuFolderCount = Just settings.searchMenuFolderCount
@@ -407,6 +414,19 @@ cardPreviewSize2 settings =
             "max-h-80"
 
 
+pdfUrl : UiSettings -> Flags -> String -> String
+pdfUrl settings flags originalUrl =
+    case settings.pdfMode of
+        Data.Pdf.Detect ->
+            Data.Pdf.detectUrl flags originalUrl
+
+        Data.Pdf.Native ->
+            originalUrl
+
+        Data.Pdf.Server ->
+            Data.Pdf.serverUrl originalUrl
+
+
 
 --- Helpers
 

modules/webapp/src/main/elm/Messages/Comp/UiSettingsForm.elm

@@ -13,9 +13,11 @@ module Messages.Comp.UiSettingsForm exposing
 
 import Data.Color exposing (Color)
 import Data.Fields exposing (Field)
+import Data.Pdf exposing (PdfMode)
 import Messages.Basics
 import Messages.Data.Color
 import Messages.Data.Fields
+import Messages.Data.PdfMode
 
 
 type alias Texts =
@@ -53,6 +55,7 @@ type alias Texts =
     , fieldsInfo : String
     , fieldLabel : Field -> String
     , templateHelpMessage : String
+    , pdfMode : PdfMode -> String
     }
 
 
@@ -127,6 +130,7 @@ for example `{{corrOrg|corrPerson|-}}` would render the organization
 and if that is not present the person. If both are absent a dash `-`
 is rendered.
 """
+    , pdfMode = Messages.Data.PdfMode.gb
     }
 
 
@@ -203,4 +207,5 @@ verknüpft werden, bis zur ersten die einen Wert enthält. Zum Beispiel:
 oder, wenn diese leer ist, die Person. Sind beide leer wird ein `-`
 dargestellt.
 """
+    , pdfMode = Messages.Data.PdfMode.de
     }

modules/webapp/src/main/elm/Messages/Data/PdfMode.elm

@@ -0,0 +1,39 @@
+{-
+   Copyright 2020 Eike K. & Contributors
+
+   SPDX-License-Identifier: AGPL-3.0-or-later
+-}
+
+
+module Messages.Data.PdfMode exposing
+    ( de
+    , gb
+    )
+
+import Data.Pdf exposing (PdfMode(..))
+
+
+gb : PdfMode -> String
+gb st =
+    case st of
+        Detect ->
+            "Detect automatically"
+
+        Native ->
+            "Use the browser's native PDF view"
+
+        Server ->
+            "Use cross-browser fallback"
+
+
+de : PdfMode -> String
+de st =
+    case st of
+        Detect ->
+            "Automatisch ermitteln"
+
+        Native ->
+            "Browsernative Darstellung"
+
+        Server ->
+            "Browserübergreifende Ersatzdarstellung"

modules/webapp/src/main/elm/Page/Home/View2.elm

@@ -460,7 +460,7 @@ searchStats texts _ settings model =
 
 
 itemCardList : Texts -> Flags -> UiSettings -> Model -> List (Html Msg)
-itemCardList texts _ settings model =
+itemCardList texts flags settings model =
     let
         previewUrl attach =
             Api.attachmentPreviewURL attach.id
@@ -489,6 +489,7 @@ itemCardList texts _ settings model =
         (Comp.ItemCardList.view2 texts.itemCardList
             itemViewCfg
             settings
+            flags
             model.itemListModel
         )
     , loadMore texts settings model

modules/webapp/src/main/elm/Page/Share/Results.elm

@@ -9,6 +9,7 @@ module Page.Share.Results exposing (view)
 
 import Api
 import Comp.ItemCardList
+import Data.Flags exposing (Flags)
 import Data.ItemSelection
 import Data.UiSettings exposing (UiSettings)
 import Html exposing (..)
@@ -18,8 +19,8 @@ import Page exposing (Page(..))
 import Page.Share.Data exposing (Model, Msg(..))
 
 
-view : Texts -> UiSettings -> String -> Model -> Html Msg
-view texts settings shareId model =
+view : Texts -> UiSettings -> Flags -> String -> Model -> Html Msg
+view texts settings flags shareId model =
     let
         viewCfg =
             { current = Nothing
@@ -32,5 +33,5 @@ view texts settings shareId model =
     in
     div []
         [ Html.map ItemListMsg
-            (Comp.ItemCardList.view2 texts.itemCardList viewCfg settings model.itemListModel)
+            (Comp.ItemCardList.view2 texts.itemCardList viewCfg settings flags model.itemListModel)
         ]

modules/webapp/src/main/elm/Page/Share/View.elm

@@ -63,7 +63,7 @@ viewContent texts flags versionInfo uiSettings shareId model =
 
 
 mainContent : Texts -> Flags -> UiSettings -> String -> Model -> Html Msg
-mainContent texts _ settings shareId model =
+mainContent texts flags settings shareId model =
     div
         [ id "content"
         , class "h-full flex flex-col"
@@ -76,7 +76,7 @@ mainContent texts _ settings shareId model =
             [ text <| Maybe.withDefault "" model.verifyResult.name
             ]
         , Menubar.view texts model
-        , Results.view texts settings shareId model
+        , Results.view texts settings flags shareId model
         ]