mirror of
https://github.com/denoland/deno.git
synced 2024-11-14 16:33:45 -05:00
58 lines
1.6 KiB
Markdown
58 lines
1.6 KiB
Markdown
# Fetch data
|
|
|
|
## Concepts
|
|
|
|
- Like browsers, Deno implements web standard APIs such as
|
|
[fetch](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API).
|
|
- Deno is secure by default, meaning explicit permission must be granted to
|
|
access the network.
|
|
- See also: Deno's [permissions](../getting_started/permissions.md) model.
|
|
|
|
## Overview
|
|
|
|
When building any sort of web application developers will usually need to
|
|
retrieve data from somewhere else on the web. This works no differently in Deno
|
|
than in any other JavaScript application, just call the the `fetch()` method.
|
|
For more information on fetch read the
|
|
[MDN documentation](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API).
|
|
|
|
The exception with Deno occurs when running a script which makes a call over the
|
|
web. Deno is secure by default which means access to IO (Input / Output) is
|
|
prohibited. To make a call over the web Deno must be explicitly told it is ok to
|
|
do so. This is achieved by adding the `--allow-net` flag to the `deno run`
|
|
command.
|
|
|
|
## Example
|
|
|
|
**Command:** `deno run --allow-net fetch.ts`
|
|
|
|
```js
|
|
/**
|
|
* Output: JSON Data
|
|
*/
|
|
const json = fetch("https://api.github.com/users/denoland");
|
|
|
|
json.then((response) => {
|
|
return response.json();
|
|
}).then((jsonData) => {
|
|
console.log(jsonData);
|
|
});
|
|
|
|
/**
|
|
* Output: HTML Data
|
|
*/
|
|
const text = fetch("https://deno.land/");
|
|
|
|
text.then((response) => {
|
|
return response.text();
|
|
}).then((textData) => {
|
|
console.log(textData);
|
|
});
|
|
|
|
/**
|
|
* Output: Error Message
|
|
*/
|
|
const error = fetch("https://does.not.exist/");
|
|
|
|
error.catch((error) => console.log(error.message));
|
|
```
|