## Advanced usage

Jekyll SEO Tag is designed to implement SEO best practices by default and to be the right fit for most sites right out of the box. If for some reason, you need more control over the output, read on:

### Disabling `<title>` output

If for some reason, you don't want the plugin to output `<title>` tags on each page, simply invoke the plugin within your template like so:

<!-- {% raw %} -->
```
{% seo title=false %}
```
<!-- {% endraw %} -->

### Disabling `<link rel="canonical">` output

If you're using another plugin to generate canonical URLs (such as [jekyll-polyglot](https://github.com/untra/polyglot) for multilingual sites), you can disable the canonical URL output:

<!-- {% raw %} -->
```
{% seo canonical=false %}
```
<!-- {% endraw %} -->

This will prevent the plugin from outputting the `<link rel="canonical">` tag, while still outputting all other SEO tags including the `<meta property="og:url">` tag.

### Author information

Author information is used to propagate the `creator` field of Twitter summary cards. This should be an author-specific, not site-wide Twitter handle (the site-wide username be stored as `site.twitter.username`).

*TL;DR: In most cases, put `author: [your Twitter handle]` in the document's front matter, for sites with multiple authors. If you need something more complicated, read on.*

There are several ways to convey this author-specific information. Author information is found in the following order of priority:

1. An `author` object, in the documents's front matter, e.g.:

  ```yml
  author:
    twitter: benbalter
  ```

2. An `author` object, in the site's `_config.yml`, e.g.:

  ```yml
  author:
    twitter: benbalter
  ```

3. `site.data.authors[author]`, if an author is specified in the document's front matter, and a corresponding key exists in `site.data.authors`. E.g., you have the following in the document's front matter:

  ```yml
  author: benbalter
  ```

  And you have the following in `_data/authors.yml`:

  ```yml
  benbalter:
    picture: /img/benbalter.png
    twitter: jekyllrb

  potus:
    picture: /img/potus.png
    twitter: whitehouse
  ```

  In the above example, the author `benbalter`'s Twitter handle will be resolved to `@jekyllrb`. This allows you to centralize author information in a single `_data/authors` file for site with many authors that require more than just the author's username.

  *Pro-tip: If `authors` is present in the document's front matter as an array (and `author` is not), the plugin will use the first author listed, as Twitter supports only one author.*

4. An author in the document's front matter (the simplest way), e.g.:

  ```yml
  author: benbalter
  ```

5. An author in the site's `_config.yml`, e.g.:

  ```yml
  author: benbalter
  ```

#### Setting author url

Starting from August 6, 2021 [Google recommends](https://developers.google.com/search/updates) to set the `author.url` property. This property helps Google to disambiguate the correct author of the article.

You can set it the same way as the other author properties. For example, you can put it in an `author` object, in the site's `_config.yml`, e.g.:

  ```yml
  author:
    name: My Name
    url: https://example.com/
  ```

### Customizing description length

By default, the description is limited to the first 100 words of the full content.

You can adjust this limit at the page level, by using the `seo_description_max_words` page property:

```yml
  seo_description_max_words: 200
```

You can also set a default site-wide value for all pages using [Front Matter defaults](https://jekyllrb.com/docs/configuration/front-matter-defaults/) in your `_config.yml` file:

```yml
defaults:
  - scope:
      path: ""
    values:
      seo_description_max_words: 200
```


### Customizing JSON-LD output

The following options can be set for any particular page. While the default options are meant to serve most users in the most common circumstances, there may be situations where more precise control is necessary.

* `seo`
  * `name` - If the name of the thing that the page represents is different from the page title. (i.e.: "Frank's Café" vs "Welcome to Frank's Café")
  * `type` - The type of things that the page represents. This must be a [Schema.org type](https://schema.org/docs/schemas.html), and will probably usually be something like [`BlogPosting`](https://schema.org/BlogPosting), [`NewsArticle`](https://schema.org/NewsArticle), [`Person`](https://schema.org/Person), [`Organization`](https://schema.org/Organization), etc.
  * `links` - An array of other URLs that represent the same thing that this page represents. For instance, Jane's bio page might include links to Jane's GitHub and Twitter profiles.
  * `date_modified` - Manually specify the `dateModified` field in the JSON-LD output to override Jekyll's own `dateModified`.
  This field will take **first priority** for the `dateModified` JSON-LD output and the article modification time for Open Graph (`article:modified_time`). This is useful when the file timestamp does not match the true time that the content was modified. A user may also install [Last Modified At](https://github.com/gjtorikian/jekyll-last-modified-at) which will offer an alternative way of providing for the `dateModified` field.

### Customizing image output

For most users, setting `image: [path-to-image]` on a per-page basis should be enough. If you need more control over how images are represented, the `image` property can also be an object, with the following options:

* `path` - The relative path to the image. Same as `image: [path-to-image]`
* `height` - The height of the Open Graph (`og:image`) image
* `width` - The width of the Open Graph (`og:image`) image
* `alt` - The alternative image text for Open Graph (`og:image:alt`) and Twitter (`twitter:image:alt`)

You can use any of the above, optional properties, like so:

```yml
image:
  path: /img/twitter.png
  height: 100
  width: 100
  alt: Twitter Logo
```

### Setting a default image

You can define a default image using [Front Matter defaults](https://jekyllrb.com/docs/configuration/front-matter-defaults/), to provide a default Twitter Card or OGP image to all of your posts and pages.

Here is a very basic example, that you are encouraged to adapt to your needs:

```yml
defaults:
  - scope:
      path: ""
    values:
      image: /assets/images/default-card.png
```

### SmartyPants Titles

Titles will be processed using [Jekyll's `smartify` filter](https://jekyllrb.com/docs/liquid/filters/). This will use SmartyPants to translate plain ASCII punctuation into "smart" typographic punctuation. This will not render or strip any Markdown you may be using in a page title.

### Setting customized Canonical URL

You can set custom Canonical URL for a page by specifying canonical_url option in page front matter.
E.g., you have the following in the page's front matter:
```yml
layout: post
title: Title of Your Post
canonical_url: 'https://github.com/jekyll/jekyll-seo-tag/'
```

Which will generate canonical_url with specified link in canonical_url.
```html
<link rel="canonical" href="https://github.com/jekyll/jekyll-seo-tag/" />
```

If no canonical_url option was specified, then uses page url for generating canonical_url.
E.g., you have not specified canonical_url in front matter:
```yml
layout: post
title: Title of Your Post
```

Which will generate following canonical_url:
```html
<link rel="canonical" href="https://example.com/title-of-your-post" />
```

### Customizing title modifier for paginated pages

You can override the default title modifier for paginated pages from `Page %{current} of %{total} for ` to a string of your
choice by setting a `seo_paginator_message` key in your `_config.yml`.

For example:

```yml
seo_paginator_message: "%<current>s / %<total>s | "
```

While the value can be any string text, we recommend using a Ruby string-template containing the variables `current` and `total`
similar to the example above, to incorporate the current page-number and total number of paginated pages in the title.

### Adding a page title category

You can optionally add a page category to its title.
This is useful for indicating to the users that some pages are logically grouped or are of a specific kind.

For example page front matter including:

```yml
title: "my page"
title_category: "category"
```

And `_config.yml` including:

```yml
title: "my site"
```

Will generate `my page | category | my site` as the page's main `<title>` tag
and `my page | category` as all other page's title declarations like `og:title`.
