I'm using Elm with mdgriffiths/elm-ui, and I've really been enjoying it. Right now, I'm trying to create a centered, wrapped row of elements:
I can get it to this point:
using this code:
button : String -> String -> Element Msg
button label url =
link
[ height (px 150)
, width (px 150)
, Border.width 1
, Background.color (rgb255 255 255 255)
]
{ url = url
, label =
Element.paragraph
[ Font.center ]
[ textEl [] label ]
}
row : Element Msg
row =
Element.wrappedRow
[ Element.spacing 25
, Element.centerX
, Element.centerY
, width (fill |> Element.maximum 600)
, Font.center
]
[ button "A" "/a"
, button "B" "/b"
, button "C" "/c"
, button "D" "/d"
]
But when I try adding Element.centerX to my buttons like this
link
[ Element.centerX
, ...
]
I get this instead:
I've also tried Font.center without success, and I don't know what else I can try.
I'm not sure if I'm missing something I should be using, or if the whole thing needs re-arranging, or if I just need to use the built-in CSS stuff.
Update:
Link to an Ellie with the issues I'm seeing.
https://ellie-app.com/7NpM6SPfhLHa1
This Github issue is useful for this problem. I'm afraid you will have to use some CSS (unless I'm missing something). I've found this before with elm-ui; every now and then it can't quite do what you want and you need a bit of CSS.
This works for me (taken from the post by AlienKevin in the link above). You need to set "marginLeft" and "marginRight" to "auto".
module Main exposing (main)
import Element as E
import Element.Border
import Html.Attributes
box : String -> E.Element msg
box label =
E.paragraph
[ E.width <| E.px 200
, Element.Border.width 1
, E.htmlAttribute (Html.Attributes.style "marginLeft" "auto")
, E.htmlAttribute (Html.Attributes.style "marginRight" "auto")
]
[ E.text label ]
row : E.Element msg
row =
E.wrappedRow []
[ box "A"
, box "B"
, box "C"
]
main =
E.layout [] row
(See here for an Ellie.)
You can also do the following:
Define the following elm-ui classes. I usually setup a UI.elm module for this
centerWrap : Attribute msg
centerWrap =
Html.Attributes.class "centerWrap"
|> htmlAttribute
dontCenterWrap : Attribute msg
dontCenterWrap =
Html.Attributes.class "dontCenterWrap"
|> htmlAttribute
Add the following to your css. Basically says center elements if has centerWrap class but not dontCenterWrap class.
:not(.dontCenterWrap).centerWrap>div.wrp {
justify-content: center !important;
}
Apply the attribute
wrappedRow [ width fill, UI.centerWrap, spaceEvenly ] [...]
Assuming you created a custom element that centerWraps and wanted to disable that you could use UI.dontCenterWrap
centerWrappedRow attr children =
wrappedRow (UI.centerWrap :: attr) children
-- somewhere else
...
centerWrappedRow [UI.dontCenterWrap] [..]
...
Related
I am new to ELM and I want to create a modal without the use of any libraries such as Bootstrap or ELM-UI. I found this simple example online which is also using JSON Decode. Is there a possibility to have the modal work simply without any framework/library and JSON Decode? How can I modify the code to simply get a working modal?
module Main exposing (main)
import Browser
import Html exposing (Html, Attribute, button, div, span, text)
import Html.Events exposing (onClick, on)
import Html.Attributes exposing (class, style)
import Json.Decode as Decode
type alias Model =
{ isVisible : Bool, count : Int }
initialModel : Model
initialModel =
{ isVisible = False, count = 0 }
type Msg
= Show
| Hide
| Increment
| Decrement
update : Msg -> Model -> Model
update msg model =
case msg of
Show ->
{ model | isVisible = True }
Hide ->
{ model | isVisible = False }
Increment ->
{ model | count = model.count + 1 }
Decrement ->
{ model | count = model.count - 1 }
view : Model -> Html Msg
view model =
div []
[ button [ onClick Show ] [ text "Show!" ]
, if model.isVisible then
div
([ class dialogContainerClass
, on "click" (containerClickDecoder Hide)
]
++ dialogContainerStyle
)
[ div dialogContentStyle
[ span [] [ text "Click anywhere outside this dialog to close it!" ]
, span [] [ text "Clicking on anything inside of this dialog works as normal." ]
, div []
[ button [ onClick Decrement ] [ text "-" ]
, text (String.fromInt model.count)
, button [ onClick Increment ] [ text "+" ]
]
]
]
else
div [] []
]
dialogContainerClass : String
dialogContainerClass = "dialog-container-class"
containerClickDecoder : msg -> Decode.Decoder msg
containerClickDecoder closeMsg =
Decode.at [ "target", "className" ] Decode.string
|> Decode.andThen
(\c ->
if String.contains dialogContainerClass c then
Decode.succeed closeMsg
else
Decode.fail "ignoring"
)
dialogContainerStyle : List (Attribute msg)
dialogContainerStyle =
[ style "position" "absolute"
, style "top" "0"
, style "bottom" "0"
, style "right" "0"
, style "left" "0"
, style "display" "flex"
, style "align-items" "center"
, style "justify-content" "center"
, style "background-color" "rgba(33, 43, 54, 0.4)"
]
dialogContentStyle : List (Attribute msg)
dialogContentStyle =
[ style "border-style" "solid"
, style "border-radius" "3px"
, style "border-color" "white"
, style "background-color" "white"
, style "height" "120px"
, style "width" "440px"
, style "display" "flex"
, style "flex-direction" "column"
, style "align-items" "center"
, style "justify-content" "center"
]
main : Program () Model Msg
main =
Browser.sandbox
{ init = initialModel
, view = view
, update = update
}
If I understand your question correctly, the problem you're trying to solve is clicking outside the modal to close it. Decoding the event object to get information about the DOM is a bit of a hack in Elm – I think you're right to try to avoid it, unless necessary. One way to achieve the same thing is to add a click event handler with stop propagation to your modal contents – this stops the click event from firing on the container when it originates from within the modal.
I've put your example code in an Ellie and made some small changes: https://ellie-app.com/b9gDPHgtz2ca1
This solution uses Html.Events.stopPropagationOn, which is like on but does a call to event.stopPropagation(). This function does require you to supply a decoder, so I'm afraid you can't get away from importing Json.Decode, but we are using the simplest possible decoder – Decode.succeed – and only to satisfy the parameters of the function.
I've added a NoOp variant to Msg, as there is nothing to do when the modal is clicked; simply attaching this event handler stops the Hide event from firing when we don't want it to.
Code
module Main exposing (main)
import Browser
import Html exposing (Attribute, Html, button, div, span, text)
import Html.Attributes exposing (class, style)
import Html.Events exposing (on, onClick)
import Json.Decode as Decode
type alias Model =
{ isVisible : Bool, count : Int }
initialModel : Model
initialModel =
{ isVisible = False, count = 0 }
type Msg
= Show
| Hide
| Increment
| Decrement
| NoOp
update : Msg -> Model -> Model
update msg model =
case msg of
Show ->
{ model | isVisible = True }
Hide ->
{ model | isVisible = False }
Increment ->
{ model | count = model.count + 1 }
Decrement ->
{ model | count = model.count - 1 }
NoOp ->
model
view : Model -> Html Msg
view model =
div []
[ button [ onClick Show ] [ text "Show!" ]
, if model.isVisible then
div
(onClick Hide
:: dialogContainerStyle
)
[ div
(onClickStopPropagation NoOp
:: dialogContentStyle
)
[ span [] [ text "Click anywhere outside this dialog to close it!" ]
, span [] [ text "Clicking on anything inside of this dialog works as normal." ]
, div []
[ button [ onClick Decrement ] [ text "-" ]
, text (String.fromInt model.count)
, button [ onClick Increment ] [ text "+" ]
]
]
]
else
div [] []
]
onClickStopPropagation : msg -> Html.Attribute msg
onClickStopPropagation msg =
Html.Events.stopPropagationOn "click" <| Decode.succeed ( msg, True )
dialogContainerStyle : List (Attribute msg)
dialogContainerStyle =
[ style "position" "absolute"
, style "top" "0"
, style "bottom" "0"
, style "right" "0"
, style "left" "0"
, style "display" "flex"
, style "align-items" "center"
, style "justify-content" "center"
, style "background-color" "rgba(33, 43, 54, 0.4)"
]
dialogContentStyle : List (Attribute msg)
dialogContentStyle =
[ style "border-style" "solid"
, style "border-radius" "3px"
, style "border-color" "white"
, style "background-color" "white"
, style "height" "120px"
, style "width" "440px"
, style "display" "flex"
, style "flex-direction" "column"
, style "align-items" "center"
, style "justify-content" "center"
]
main : Program () Model Msg
main =
Browser.sandbox
{ init = initialModel
, view = view
, update = update
}
Disclaimer: I realized this was a maybe stupid question after I finished writing it. Please don't spend too much time reading it. I am very new to Elm, functional programming, and not a UI buff.
I have a view in Elm that returns Html Msg and takes in a model. Using the simple increment demo as en example, I have this typical setup:
module Main exposing (..)
import Browser
import Html exposing (Html, button, div, text)
import Html.Events exposing (onClick)
-- MAIN
main =
Browser.sandbox { init = init, update = update, view = view }
-- MODEL
type alias Model = Int
init : Model
init =
0
-- UPDATE
type Msg
= Increment
| Decrement
update : Msg -> Model -> Model
update msg model =
case msg of
Increment ->
model + 1
Decrement ->
model - 1
-- VIEW
view : Model -> Html Msg
view model =
div []
[ button [ onClick Decrement ] [ text "-" ]
, div [] [ text (String.fromInt model) ]
, button [ onClick Increment ] [ text "+" ]
]
I have a button component that's quite complex which I would like to extract into a separate function. I'm able to do this with normal Html, i.e.
-- VIEW
some_html : Html msg
some_html =
text "FOO"
view : Model -> Html Msg
view model =
div []
[ button [ onClick Decrement ] [ text "-" ]
, div [] [ text (String.fromInt model) ]
, button [ onClick Increment ] [ text "+" ]
, some_html
]
I can also pass the Msg type I've defined and have the "sub-function" call the action:
-- VIEW
make_button : Msg -> Html Msg
make_button msg =
button [ onClick msg ] [ text "-" ]
view : Model -> Html Msg
view model =
div []
[ make_button Decrement
, div [] [ text (String.fromInt model) ]
, button [ onClick Increment ] [ text "+" ]
]
My problem and question is:
I would like to be able to have my make_button function be able to handle multiple actions. One way I have found that works is to pass all possible actions and then a key, i.e.
-- VIEW
make_button : Msg -> Msg -> String -> Html Msg
make_button decr incr which =
if which == "Decrement" then
button [ onClick decr ] [ text "-" ]
else button [ onClick incr ] [ text "+" ]
view : Model -> Html Msg
view model =
div []
[ make_button Decrement Increment "Decrement"
, div [] [ text (String.fromInt model) ]
, make_button Decrement Increment "Increment" -- doesn't matter here.
]
But this becomes cumbersome when the number of actions is large (in my use case I have 20 or so actions).
Should I create a dictionary of sorts? Is there a way this is done? Is this a bad thing to do? Please give me grief.
I am imaging scenarios where many nested child components might want to have the ability to call any Action of the parent component on the fly without this being hard-coded, which is why I decided to still ask the question.
Thanks.
You're definitely over thinking things! The way you would do this is
-- camel case is the convention in Elm ;)
makeButton : Msg -> Html Msg
makeButton msg =
button
[ onClick msg ]
[ text <|
-- an if statement would also work in this case
case msg of
Increment ->
"+"
Decrement ->
"-"
]
view : Model -> Html Msg
view model =
div []
[ makeButton Decrement
, div [] [ text (String.fromInt model) ]
, makeButton Increment
]
I am building my first app in Elm and decided to use Style Elements package instead of CSS.
This is the layout that I am attempting. Its a single page app that does not scroll.
here is some code
view : Model -> Html Msg
view model =
layout Styles.stylesheet <|
pageWrapper
pageWrapper : Element Styles variation Msg
column Page
[ width (percent 100), height (percent 100) ]
[ navMain
, contentArea
]
navMain : Element Styles variation Msg
navMain =
row Navigation
[ spread, padding 10 ]
[ el (Nav Logo) [ width (px 50)] (text "Logo")
, row (Nav Link)
[ padding 15, spacing 10]
[ el (Nav Link) [] (text "About")
, el (Nav Link) [] (text "Services")
, el (Nav Link) [] (text "Team")
, el (Nav Link) [] (text "Location")
, el (Nav Link) [] (text "Contact")
]
]
contentArea : Element Styles variation Msg
contentArea =
-- At this point I thought I would make a row with an el with the image
and a column containing the other two images. And other than creating heights with pixels I don't know how to extend the main content to the bottom of the page.
What are some good example apps I can look at to get a good idea of how to control the layout? I have looked through several, and I feel like I am just missing something very obvious because so far SE has been awesome to work with!
Here's a very basic example:
https://ellie-app.com/k25rby75Da1/1
I've left the heights of the elements undefined below but you should be able to figure that out to suit your needs. I updated the ellie link to a version that I think better approximates the height in your example.
module Main exposing (main)
import Html
import Html.Attributes
import Color
import Style
import Style.Font as Font
import Style.Color as Color
import Element exposing (..)
import Element.Attributes exposing (..)
main =
Html.beginnerProgram
{ model = model
, update = update
, view = view
}
type alias Model =
{ navbar : String
, leftcontent : String
, rightcontent : { top : String, bottom : String }
}
model : Model
model =
{ navbar = "This is the navbar"
, leftcontent = "This is the left column content"
, rightcontent =
{ top = "This is the right top content"
, bottom = "This is the right bottom content"
}
}
update model msg =
model
type MyStyles = Navbar | Left | RightTop | RightBottom | None
stylesheet =
Style.styleSheet
[ Style.style Navbar [ Color.background Color.red ]
, Style.style Left [ Color.background Color.blue ]
, Style.style RightTop [Color.background Color.purple ]
, Style.style RightBottom [Color.background Color.gray ]
]
view model =
Element.viewport stylesheet <|
(column None [] [
row Navbar [] [ text model.navbar ]
, wrappedRow None []
[ column Left [ width (percent 50)] [ text model.leftcontent ]
, wrappedColumn None [ width (percent 50)]
[ el RightTop [ width fill] (text model.rightcontent.top)
, el RightBottom [ width fill ] (text model.rightcontent.bottom)
]
]])
I am referring to this example in http://elm-lang.org/examples/radio-buttons. I don't see anywhere whereby the state of the buttons is being managed.
In my own little Elm project I need to do something like
label []
[ input
[ type_ "radio"
, checked (model.choosenSize == size)
, onClick (SetSize size)
] []
, text (sizeToString size)
]
Without managing the checked attribute, all the radio buttons will remain checked after you click on it.
So what is the magic in the example?
The example you are referring is very simple. It doesn't explicitly manage the state of the buttons. Instead, their state is managed by the browser. In a real application, of course, you would better manage it explicitly. Something like:
view : Model -> Html Msg
view model =
div []
[ fieldset []
[ radio "Small" (model.fontSize == Small) (SwitchTo Small)
, radio "Medium" (model.fontSize == Medium) (SwitchTo Medium)
, radio "Large" (model.fontSize == Large) (SwitchTo Large)
]
, Markdown.toHtml [ sizeToStyle model.fontSize ] model.content
]
radio : String -> Bool -> msg -> Html msg
radio value isChecked msg =
label
[ style [("padding", "20px")]
]
[ input [ type_ "radio", checked isChecked, name "font-size", onClick msg ] []
, text value
]
(I added a Bool argument to radio)
I'm using the demo codebase of elm-mdl as a starting point for my elm project. I have a situation where I need to click a button on one tab (e.g. "tab X") and mutate the state of a different tab (e.g. "tab Y").
Every way I've wired it up so far does not work. This seems like an odd case because the parent of all tabs (e.g. Layout) in the demo codebase is "Demo". It seems in my case that the dependency graph become convoluted because the effect would reach across "Demo" children.
How can this be done? I'm running 0.18.0.
https://github.com/debois/elm-mdl/tree/v8/demo
I've done an example playing around with what I've understand from your question.
I think your issue have to be that you are not passing the model through your tabs , so they are not rendering data related to the current state, instead you should be taking data from the initial model which always keeps inmutable.
Starting from the example code you should have this:
view : Model -> Html Msg
view model =
Tabs.render Mdl
[ 0 ]
model.mdl
[ Tabs.ripple
, Tabs.onSelectTab SelectTab
, Tabs.activeTab model.tab
]
[ Tabs.label
[ Options.center ]
[ Icon.i "info_outline"
, Options.span [ css "width" "4px" ] []
, text "About tabs"
]
, Tabs.label
[ Options.center ]
[ Icon.i "code"
, Options.span [ css "width" "4px" ] []
, text "Example"
]
]
[ case model.tab of
0 ->
tab0 model
_ ->
defaultTab model
]
My working example is here