https://github.com/jg-l/metadata_fetch
A dart library for extracting metadata in web pages. Supports Open Graph, Meta, Twitter Cards, and Structured Data (Json-LD)
https://github.com/jg-l/metadata_fetch
dart extract-metadata flutter meta metadata opengraph parse structured-data twitter-cards
Last synced: about 1 month ago
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A dart library for extracting metadata in web pages. Supports Open Graph, Meta, Twitter Cards, and Structured Data (Json-LD)
- Host: GitHub
- URL: https://github.com/jg-l/metadata_fetch
- Owner: jg-l
- License: bsd-3-clause
- Created: 2020-02-19T18:39:05.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2024-09-10T03:22:05.000Z (over 1 year ago)
- Last Synced: 2025-10-23T07:31:56.713Z (5 months ago)
- Topics: dart, extract-metadata, flutter, meta, metadata, opengraph, parse, structured-data, twitter-cards
- Language: Dart
- Homepage:
- Size: 55.7 KB
- Stars: 45
- Watchers: 1
- Forks: 74
- Open Issues: 18
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# Metadata Fetch
A dart library for extracting metadata in web pages. Supports OpenGraph, Meta, Twitter Cards, and Structured Data (Json-LD)
Available on Pub Dev:
[Pub](https://pub.dev/packages/metadata_fetch)
## Metadata Structure
```yaml
Metadata:
- title
- description
- image
- url
```
## Usage
### Extract Metadata for a given URL
```dart
import 'package:metadata_fetch/metadata_fetch.dart';
main() async {
final myURL = 'https://flutter.dev';
// Use the `MetadataFetch.extract()` function to fetch data from the url
var data = await MetadataFetch.extract(myURL);
print(data.title) // Flutter - Beautiful native apps in record time
print(data.description) // Flutter is Google's UI toolkit for crafting beautiful...
print(data.image) // https://flutter.dev/images/flutter-logo-sharing.png
print(data.url) // https://flutter.dev/
var dataAsMap = data.toMap();
}
```
### Parsing Manually
#### Get aggregated Metadata from a document
This method prioritizes Open Graph data, followed by Twitter Card, JSON-LD and finally falls back to HTML metadata.
```dart
import 'package:metadata_fetch/metadata_fetch.dart';
import 'package:http/http.dart' as http;
void main () async {
final myURL = 'https://flutter.dev';
// makes a call
var response = await http.get(myURL);
// Convert Response to a Document. The utility function `MetadataFetch.responseToDocument` is provided or you can use own decoder/parser.
var document = MetadataFetch.responseToDocument(response);
// get aggregated metadata
var data = MetadataParser.parse(document);
print(data);
}
```
#### Manually specify which Metadata parser to use
```dart
import 'package:metadata_fetch/metadata_fetch.dart';
import 'package:http/http.dart' as http;
void main () async {
final myURL = 'https://flutter.dev';
// Makes a call
var response = await http.get(myURL);
// Convert Response to a Document. The utility function `responseToDocument` is provided or you can use own decoder/parser.
var document = responseToDocument(response);
// Get OpenGraph Metadata
var ogData = MetadataParser.OpenGraph(document);
print(ogData);
// Get Html metadata
var htmlData = MetadataParser.HtmlMeta(document);
print(htmlData);
// Get Structured Data
var structuredData = MetadataParser.JsonLdSchema(document);
print(structuredData);
// Get Twitter Cards Data
var twitterCardData = MetadataParser.TwitterCard(document);
print(twitterCardData);
}
```
#### Provide a fallback url when manually parsing
If the parsers cannot extract a URL from the document, you may optionally provide a URL in `MetadataFetch.parse()`.
This URL will be added in the final `Metadata` structure, and is used to resolve images with relative URLs (non-absolute URLs).
```dart
import 'package:metadata_fetch/metadata_fetch.dart';
import 'package:http/http.dart' as http;
void main () async {
final myURL = 'https://flutter.dev';
// makes a call
var response = await http.get(myURL);
// Convert Response to a Document. The utility function `MetadataFetch.responseToDocument` is provided or you can use own decoder/parser.
var document = MetadataFetch.responseToDocument(response);
// get aggregated metadata, supplying a fallback URL
// Used for images with relative URLs
var data = MetadataParser.parse(document, url:myURL);
print(data);
}
```
## Credit
This library is inspired by [open_graph_parser](https://github.com/Patte1808/open_graph_parser).
However this one tries to be more general.
## Roadmap
- Weighted or Preferred Metadata. Can assign custom weights for each parser to provide a fallback priority sytem
- Improve Documentation
## Questions, Bugs, and Feature Requests
Please forward all queries about this project to the [issue tracker](https://github.com/jg-l/metadata_fetch/issues).