### Run Eww Daemon and Open Widget

Source: https://github.com/elkowar/eww/blob/master/docs/src/eww.md

Start the Eww daemon and then open a widget by its name. Ensure the Eww binary is in your PATH or run from its directory.

```bash
./eww daemon
./eww open <window_name>
```

--------------------------------

### Build Eww for X11

Source: https://github.com/elkowar/eww/blob/master/docs/src/eww.md

Build the Eww project in release mode with X11 features enabled. Ensure you have the necessary prerequisites installed.

```bash
cargo build --release --no-default-features --features x11
```

--------------------------------

### Build Eww for Wayland

Source: https://github.com/elkowar/eww/blob/master/docs/src/eww.md

Build the Eww project in release mode with Wayland features enabled. This is for Wayland environments. Ensure you have the necessary prerequisites installed.

```bash
cargo build --release --no-default-features --features=wayland
```

--------------------------------

### JSON Access Example

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Demonstrates accessing fields within a JSON structure stored in a variable. Supports dot notation, bracket notation with string keys, and bracket notation with numeric indices.

```lisp
json_variable.field_name
```

```lisp
json_variable["field_name"]
```

```lisp
json_variable[12]
```

--------------------------------

### Conditional Expression

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Example of a conditional expression (ternary operator). It evaluates a condition and returns one of two values based on the boolean result.

```lisp
condition ? 'value' : 'other value'
```

--------------------------------

### Navigate to Build Directory

Source: https://github.com/elkowar/eww/blob/master/docs/src/eww.md

Change the current directory to the release build output directory.

```bash
cd target/release
```

--------------------------------

### Navigate to Eww Directory

Source: https://github.com/elkowar/eww/blob/master/docs/src/eww.md

Change the current directory to the cloned Eww repository.

```bash
cd eww
```

--------------------------------

### Make Eww Executable

Source: https://github.com/elkowar/eww/blob/master/docs/src/eww.md

Grant execute permissions to the Eww binary.

```bash
chmod +x ./eww
```

--------------------------------

### Invoke a custom widget

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Demonstrates how to call the custom greeter widget within a window definition.

```lisp
(defwindow example
           ; ... values omitted
  (greeter :text "Say hello!"
           :name "Tim"))
```

--------------------------------

### Open windows with specific IDs

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Use the --id flag with the open command to spawn multiple instances of the same window configuration.

```bash
eww open my_bar --screen 0 --id primary
eww open my_bar --screen 1 --id secondary
```

```bash
eww open-many my_config:primary my_config:secondary
```

--------------------------------

### Use a wrapper widget

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Shows how to pass a button as a child to the labeled-container widget.

```lisp
(labeled-container :name "foo"
  (button :onclick "notify-send hey ho"
    "click me"))
```

--------------------------------

### Include external configuration files

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Use the include directive to import contents from another yuck file into the current configuration.

```lisp
(include "./path/to/your/file.yuck")
```

--------------------------------

### Define a window with arguments

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Define window arguments in the defwindow block to allow for dynamic configuration based on input parameters. These arguments are constant once the window is opened.

```lisp
(defwindow my_bar [arg1 ?arg2]
          :geometry (geometry
                       :x      "0%"
                       :y      "6px"
                       :width  "100%"
                       :height { arg1 == "small" ? "30px" : "40px" }
                       :anchor "top center")
          :stacking   "bg"
          :windowtype "dock"
          :reserve    (struts :distance "50px" :side "top")
    (my_widget :arg2 arg2))
```

--------------------------------

### Create a wrapper widget with children

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Uses the children placeholder to allow a custom widget to accept and render child elements.

```lisp
(defwidget labeled-container [name]
  (box :class "container"
    name
    (children)))
```

--------------------------------

### Pass arguments to windows

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Provide arguments to windows using the --arg flag during the open or open-many commands.

```bash
eww open my_bar --id primary --arg arg1=some_value --arg arg2=another_value
```

```bash
# Please note that `--arg` option must be given after all the windows names
eww open-many my_bar:primary --arg primary:arg1=some_value --arg primary:arg2=another_value
```

--------------------------------

### Define a top-level window

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Use the defwindow macro to specify window properties like geometry, monitor, and content.

```lisp
(defwindow example
           :monitor 0
           :geometry (geometry :x "0%"
                               :y "20px"
                               :width "90%"
                               :height "30px"
                               :anchor "top center")
           :stacking "fg"
           :reserve (struts :distance "40px" :side "top")
           :windowtype "dock"
           :wm-ignore false
  "example content")
```

--------------------------------

### Clone Eww Repository

Source: https://github.com/elkowar/eww/blob/master/docs/src/eww.md

Clone the Eww project repository from GitHub to your local machine.

```bash
git clone https://github.com/elkowar/eww
```

--------------------------------

### Define a custom greeter widget

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Defines a widget with an optional text attribute and a required name attribute.

```lisp
(defwidget greeter [?text name]
  (box :orientation "horizontal"
       :halign "center"
    text
    (button :onclick "notify-send 'Hello' 'Hello, ${name}'"
      "Greet")))
```

--------------------------------

### View Eww Logs

Source: https://github.com/elkowar/eww/blob/master/docs/src/troubleshooting.md

This command displays the current logs for the Eww application, useful for diagnosing issues.

```bash
eww logs
```

--------------------------------

### Open GTK Debugger

Source: https://github.com/elkowar/eww/blob/master/docs/src/working_with_gtk.md

Run this command in your terminal to open the GTK debugger for Eww. Use it to inspect and debug styling issues.

```bash
eww inspector
```

--------------------------------

### Apply arguments across multiple windows

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Apply arguments to multiple windows simultaneously or target specific windows by name in open-many.

```bash
eww open-many my_bar:primary my_bar:secondary --arg gui_size="small"
```

```bash
eww open-many my_primary_bar --arg my_primary_bar:screen=0
```

--------------------------------

### Debug Eww Widget Structure

Source: https://github.com/elkowar/eww/blob/master/docs/src/troubleshooting.md

This command provides detailed information about your widget's structure and other debugging data.

```bash
eww debug
```

--------------------------------

### Inspect Eww State

Source: https://github.com/elkowar/eww/blob/master/docs/src/troubleshooting.md

Use this command to view the current state of all variables managed by Eww.

```bash
eww state
```

--------------------------------

### Time Formatting with Timezone

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Demonstrates formatting a UNIX timestamp into a human-readable string using a specified format and timezone. Refer to chrono's documentation for format strings and timezones.

```lisp
formattime(unix_timestamp, "%Y-%m-%d %H:%M:%S", "America/New_York")
```

--------------------------------

### Environment Variable Access

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Shows how to retrieve the value of an environment variable using the get_env function.

```lisp
get_env("MY_VARIABLE")
```

--------------------------------

### Byte Formatting (IEC)

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Formats a byte count into a human-readable string using IEC units (KiB, MiB, GiB). Supports negative byte counts and an option for compact output.

```lisp
formatbytes(bytes, false, "iec")
```

```lisp
formatbytes(bytes, true, "iec")
```

--------------------------------

### Generate widgets from JSON using for-element

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Use the for-element to iterate over a JSON array and dynamically create widgets within a container.

```lisp
(defvar my-json "[1, 2, 3]")

; Then, inside your widget, you can use
(box
  (for entry in my-json
    (button :onclick "notify-send 'click' 'button ${entry}'"
      entry)))
```

--------------------------------

### Byte Formatting (SI)

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Formats a byte count into a human-readable string using SI units (KB, MB, GB). Supports negative byte counts and an option for compact output.

```lisp
formatbytes(bytes, false, "si")
```

```lisp
formatbytes(bytes, true, "si")
```

--------------------------------

### Basic Expression Language Usage

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Demonstrates embedding expressions within strings and conditional attribute values. Expressions can perform math, string interpolation, and conditional logic.

```lisp
(box
  "Some math: ${12 + foo * 10}"
  (button :class {button_active ? "active" : "inactive"}
          :onclick "toggle_thing"
    {button_active ? "disable" : "enable"}))
```

--------------------------------

### Manually Reload Eww

Source: https://github.com/elkowar/eww/blob/master/docs/src/troubleshooting.md

If hot reloading is not functioning, use this command to manually reload the Eww configuration.

```bash
eww reload
```

--------------------------------

### Render specific children by index

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Uses the nth attribute of the children placeholder to place specific child elements into different containers.

```lisp
(defwidget two-boxes []
  (box
    (box :class "first" (children :nth 0))
    (box :class "second" (children :nth 1))))
```

--------------------------------

### Define and use a literal widget

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Use the literal widget to render a dynamically generated Yuck widget tree from a string variable. Note that this operation is computationally expensive and should be used sparingly.

```lisp
(defvar variable_containing_yuck
  "(box (button 'foo') (button 'bar'))")

; Then, inside your widget, use:
(literal :content variable_containing_yuck)
```

--------------------------------

### Define a listening variable

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Listening variables run a script once and update the variable value whenever the script outputs a new line. This is highly efficient for monitoring continuous data streams.

```lisp
(deflisten foo :initial "whatever"
  `tail -F /tmp/some_file`)
```

--------------------------------

### jq Function Usage

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Illustrates using the jq function to process JSON data with jq-compatible filters. The 'r' flag can be used for raw output.

```lisp
jq(json_value, ".field | .subfield")
```

```lisp
jq(json_value, ".field | .subfield", ["r"])
```

--------------------------------

### Kill Eww Daemon

Source: https://github.com/elkowar/eww/blob/master/docs/src/troubleshooting.md

Use this command to stop the Eww daemon. Re-open your window with the `--debug` flag afterwards for additional log output.

```bash
eww kill
```

--------------------------------

### Regex Match Operator

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Illustrates the regex match operator (=~). The left-hand side is the regex pattern, and the right-hand side is the string to test against. Supports Rust regex syntax.

```lisp
workspace.name =~ '^special:.+$'
```

--------------------------------

### Time Formatting without Timezone

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Shows formatting a UNIX timestamp using the system's local timezone. Uses chrono's documentation for format string details.

```lisp
formattime(unix_timestamp, "%Y-%m-%d %H:%M:%S")
```

--------------------------------

### Define a basic variable

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Basic variables require manual updates via the eww update command and do not change automatically.

```lisp
(defvar foo "initial value")
```

--------------------------------

### Safe Access Operator

Source: https://github.com/elkowar/eww/blob/master/docs/src/expression_language.md

Shows the Safe Access operator (?.) for accessing object fields or array elements. It returns null if the left-hand side is null or an empty string, preventing errors.

```lisp
object.field?.nested_field
```

```lisp
array[index]?.[nested_index]
```

--------------------------------

### Define a polling variable

Source: https://github.com/elkowar/eww/blob/master/docs/src/configuration.md

Polling variables execute a shell script at a specified interval. The :run-while property can be used to conditionally enable or disable the polling process.

```lisp
(defvar time-visible false)   ; for :run-while property of below variable
                              ; when this turns true, the polling starts and
                              ; var gets updated with given interval

(defpoll time :interval "1s"
              :initial "initial-value"  ; optional, defaults to poll at startup
              :run-while time-visible   ; optional, defaults to 'true'
  `date +%H:%M:%S`)
```

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