Expressify reactive examples (#1078)

Co-authored-by: Garrick Aden-Buie <[email protected]>

Author: Gordon Shotwell

shiny/api-examples/Progress/app-express.py

@@ -0,0 +1,21 @@
+import asyncio
+
+from shiny import reactive
+from shiny.express import input, render, ui
+
+ui.input_action_button("button", "Compute")
+
+
+@render.text
+@reactive.event(input.button)
+async def compute():
+    with ui.Progress(min=1, max=15) as p:
+        p.set(message="Calculation in progress", detail="This may take a while...")
+
+        for i in range(1, 15):
+            p.set(i, message="Computing")
+            await asyncio.sleep(0.1)
+            # Normally use time.sleep() instead, but it doesn't yet work in Pyodide.
+            # https://github.com/pyodide/pyodide/issues/2354
+
+    return "Done computing!"

shiny/api-examples/Value/app-core.py

@@ -1,24 +1,24 @@
 from shiny import App, Inputs, Outputs, Session, reactive, render, ui
 
-app_ui = ui.page_fluid(
-    ui.input_action_button("minus", "-1"),
-    " ",
-    ui.input_action_button("plus", "+1"),
-    ui.br(),
+app_ui = ui.page_sidebar(
+    ui.sidebar(
+        ui.input_action_button("minus", "-1"),
+        ui.input_action_button("plus", "+1"),
+    ),
     ui.output_text("value"),
 )
 
 
 def server(input: Inputs, output: Outputs, session: Session):
     val = reactive.Value(0)
 
-    @reactive.Effect
+    @reactive.effect
     @reactive.event(input.minus)
     def _():
         newVal = val.get() - 1
         val.set(newVal)
 
-    @reactive.Effect
+    @reactive.effect
     @reactive.event(input.plus)
     def _():
         newVal = val.get() + 1

shiny/api-examples/Value/app-express.py

@@ -0,0 +1,28 @@
+from shiny import reactive
+from shiny.express import input, render, ui
+
+val = reactive.Value(0)
+
+
+@reactive.effect
+@reactive.event(input.minus)
+def _():
+    newVal = val.get() - 1
+    val.set(newVal)
+
+
+@reactive.effect
+@reactive.event(input.plus)
+def _():
+    newVal = val.get() + 1
+    val.set(newVal)
+
+
+with ui.sidebar():
+    ui.input_action_button("minus", "-1")
+    ui.input_action_button("plus", "+1")
+
+
+@render.text
+def value():
+    return str(val.get())

shiny/api-examples/calc/app-core.py

@@ -4,16 +4,18 @@
 from shiny import App, Inputs, Outputs, Session, reactive, render, ui
 
 app_ui = ui.page_fluid(
-    ui.input_action_button("first", "Invalidate first (slow) computation"),
-    " ",
-    ui.input_action_button("second", "Invalidate second (fast) computation"),
-    ui.br(),
-    ui.output_ui("result"),
+    ui.card(
+        ui.layout_columns(
+            ui.input_action_button("first", "Invalidate first (slow) computation"),
+            ui.input_action_button("second", "Invalidate second (fast) computation"),
+        ),
+        ui.output_text_verbatim("result"),
+    )
 )
 
 
 def server(input: Inputs, output: Outputs, session: Session):
-    @reactive.Calc
+    @reactive.calc
     def first():
         input.first()
         p = ui.Progress()
@@ -23,12 +25,12 @@ def first():
         p.close()
         return random.randint(1, 1000)
 
-    @reactive.Calc
+    @reactive.calc
     def second():
         input.second()
         return random.randint(1, 1000)
 
-    @render.ui
+    @render.text
     def result():
         return first() + second()
 

shiny/api-examples/calc/app-express.py

@@ -0,0 +1,32 @@
+import random
+import time
+
+from shiny import reactive
+from shiny.express import input, render, ui
+
+
+@reactive.calc
+def first():
+    input.first()
+    p = ui.Progress()
+    for i in range(30):
+        p.set(i / 30, message="Computing, please wait...")
+        time.sleep(0.1)
+    p.close()
+    return random.randint(1, 1000)
+
+
+@reactive.calc
+def second():
+    input.second()
+    return random.randint(1, 1000)
+
+
+with ui.card():
+    with ui.layout_columns():
+        ui.input_action_button("first", "Invalidate first (slow) computation")
+        ui.input_action_button("second", "Invalidate second (fast) computation")
+
+    @render.text
+    def result():
+        return first() + second()

shiny/api-examples/effect/app-express.py

@@ -0,0 +1,15 @@
+from shiny import reactive
+from shiny.express import input, ui
+
+ui.input_action_button("show", "Show modal dialog")
+
+
+@reactive.effect
+@reactive.event(input.show)
+def show_important_message():
+    m = ui.modal(
+        "This is a somewhat important message.",
+        easy_close=True,
+        footer=None,
+    )
+    ui.modal_show(m)

shiny/api-examples/invalidate_later/app-core.py

@@ -2,16 +2,11 @@
 
 from shiny import App, Inputs, Outputs, Session, reactive, render, ui
 
-app_ui = ui.page_fluid(ui.output_ui("value"))
+app_ui = ui.page_fluid(ui.output_text("value"))
 
 
 def server(input: Inputs, output: Outputs, session: Session):
-    @reactive.Effect
-    def _():
-        reactive.invalidate_later(0.5)
-        print("Random int: ", random.randint(0, 10000))
-
-    @render.ui
+    @render.text
     def value():
         reactive.invalidate_later(0.5)
         return "Random int: " + str(random.randint(0, 10000))

shiny/api-examples/invalidate_later/app-express.py

@@ -0,0 +1,10 @@
+import random
+
+from shiny import reactive
+from shiny.express import render
+
+
+@render.text
+def value():
+    reactive.invalidate_later(0.5)
+    return "Random int: " + str(random.randint(0, 10000))

shiny/api-examples/isolate/app-express.py

@@ -0,0 +1,23 @@
+import matplotlib.pyplot as plt
+import numpy as np
+
+from shiny import reactive
+from shiny.express import input, render, ui
+
+ui.input_slider("n", "Number of observations", min=0, max=1000, value=500)
+ui.input_action_button("go", "Go!", class_="btn-success")
+
+
+@render.plot(alt="A histogram")
+def plot():
+    # Take a reactive dependency on the action button...
+    input.go()
+
+    # ...but don't take a reactive dependency on the slider
+    with reactive.isolate():
+        np.random.seed(19680801)
+        x = 100 + 15 * np.random.randn(input.n())
+
+    fig, ax = plt.subplots()
+    ax.hist(x, bins=30, density=True)
+    return fig

shiny/api-examples/poll/app-core.py

@@ -89,9 +89,8 @@ def stock_quotes() -> pd.DataFrame:
 # === Define the Shiny UI and server ===============================
 
 app_ui = ui.page_fluid(
-    ui.row(
-        ui.column(
-            8,
+    ui.layout_columns(
+        ui.card(
             ui.markdown(
                 """
                 # `shiny.reactive.poll` demo
@@ -100,11 +99,14 @@ def stock_quotes() -> pd.DataFrame:
                 case, an in-memory sqlite3) with the help of `shiny.reactive.poll`.
                 """
             ),
-            class_="mb-3",
+            ui.input_selectize(
+                "symbols", "Filter by symbol", [""] + SYMBOLS, multiple=True
+            ),
+            ui.output_data_frame("table"),
+            fill=False,
         ),
-    ),
-    ui.input_selectize("symbols", "Filter by symbol", [""] + SYMBOLS, multiple=True),
-    ui.output_ui("table"),
+        col_widths=[8, 4],
+    )
 )
 
 
@@ -115,13 +117,9 @@ def filtered_quotes():
             df = df[df["symbol"].isin(input.symbols())]
         return df
 
-    @render.ui
+    @render.data_frame
     def table():
-        return ui.HTML(
-            filtered_quotes().to_html(
-                index=False, classes="table font-monospace w-auto"
-            )
-        )
+        return filtered_quotes()
 
 
 app = App(app_ui, server)