kminevskiy
Hey folks,
Does anyone know what could cause the following behavior: I have a live view template and in it I conditionally render a form (based on the value inside the socket assigns).
<%= if length(@users) > 0 do %>
...
<% end %>
When the length changes, it used to render a form, but now nothing happens. If I prepend that first line with, say, a tag <p><%= length(@users) %></p> Everything (showing the form dynamically based on the length of @users list) works as expected. I am pretty sure the code worked as is a few weeks ago before I updated to the latest Live View (but I’m not even sure it’s an issue with Live View), among other packages. Am I missing some new behavior introduced recently or is there something else I’m not doing correctly?
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benwilson512
If you updated live view, make sure to
rm -rf node_modules && npm installagain, sometimes it doesn’t pick up changes.Most Liked
NobbZ
You shouldn’t to length like this. This will always iterate and count the full list.
Use something like
match?([_|_], @users)instead.PJUllrich
This might not help in this particular case, but I recently learned that a template gets rendered and send over the websocket connection every time the socket assigns are changed when it isn’t in the .leex format, so when it is a .eex file. Just changing all file formats to .leex reduced the websocket traffic by a lot! So, whenever you do
<%= render "my_template.html", assigns %>inside a template, make sure thatmy_templateis of the format .leexcarterbryden
I had a similar issue with conditional rendering with liveview. I posted an issue but I just haven’t had enough time to create a reproduction repo publically (client project). In my case it seemed like it might be related to a nested liveview inside a conditional in a liveview template. Still don’t have a fix for it, I just changed the way I was rendering things to work around needing the if statement. I’ll post here if I do figure it out.