Syntax

Evidence flavored Markdown extends markdown with additional functionality.

Markdown

Evidence supports almost all Markdown syntax. See Markdown Reference.

# Evidence uses Markdown

Markdown can be used to write expressively in text.
- it supports lists,
- **bolding**, _italics_ and `inline code`,
- links to [external sites](https://google.com) and other [Evidence pages](/another/page)

## Images 🖼️

Evidence looks for images in your `static` folder, e.g. `static/my-logo.png`.
![Company Logo](my-logo.png)

SQL

Markdown code fences in Evidence run SQL queries and return data. The SQL dialect matches the database you're connecting to. More on Queries.

```orders_by_month
select 
    date_trunc('month', order_datetime) as order_month,
    count(*) as number_of_orders,
    sum(sales) as sales_usd
from orders
group by 1, order by 1 desc
```

Components

Evidence has a built in component library to create charts and other visual elements. More on Components.

<LineChart 
    data = {orders_by_month}    
    y = sales_usd 
    title = 'Sales by Month, USD' 
/>

Expressions

Curly braces execute JavaScript expressions.

2 + 2 = {2 + 2} 
<!-- Result: 2 + 2 = 4 -->

There are {orders.length} months of data.  
<!-- Result: There are 36 months of data. -->

There were {orders_by_month[0].number_of_orders} orders last month. 
<!-- Result: There were 3634 orders last month. -->

Loops

Create repeating elements by looping through data. More on Loops.

{#each orders_by_month as month}

- There were <Value data={month} column=number_of_orders/> orders in <Value data={month} />. 

{/each}

If / Else

Control what is displayed using data through if and else statements. More on If / Else.

{#if orders_by_month[0].sales_usd > orders_by_month[1].sales_usd} 

Sales are up month-over-month.

{:else} 

Sales are down vs last month. See [category detail](/sales-by-category).

{/if}

Page Variables

There are a number of variables available to access information about the current page. These are particularly useful when creating templated pages and filters. They use the syntax {$...}

The current page path is: {$page.path} 
<!-- Result: The current page path is: /core-concepts/syntax/ -->

Code Fences in Other Languages

It can be useful to include code that isn't SQL, eg for documentation or examples.

If a code fence is named one of the reserved language names, such as python or r, the code fence will render a code block. The code is not executed.

```python
names = ["Alice", "Bob", "Charlie"]
for name in names:
    print("Hello, " + name)
```