Editing Template:Mainimage

<includeonly>[[File:{{#setmainimage:{{{1}}}}}|thumb|right|{{{3|}}}|{{{2}}}]][[Category:Articles with main image override]]</includeonly><noinclude>
<nowiki>[[File:{{#setmainimage:{{{1}}}}}|thumb|right|{{{3|}}}|{{{2}}}]]</nowiki>

==Usage==
<span style="color: #f00; font-size: larger;">'''Please use this template only when necessary, as the default automated selections made by PageImages will usually choose the best image.'''</span>

Include an image into an article and mark it as the main article image, for SEO and social media integration purposes. This ''overrides'' any automated determinations made by [[mw:Extension:PageImages|Extension:PageImages]] when they are used by [[mw:Extension:OpenGraphMeta|Extension:OpenGraphMeta]], but not currently for any other purpose, ie., in the [[mw:Extension:MobileFrontend|MobileFrontend]]. '''Use of this template is not required in order to assign a page image''' - note that ''no image'' has been selected for a page until it has been ''edited at least once'' since PageImages was installed; if you are not seeing good results when sharing or tweeting a page, '''please try making a minor edit to that article before resorting to use of this template'''.
Arguments:
# Image name, without namespace prefix
# Caption
# Optional: Image size

==How to check if a PageImage is assigned==
In your browser of choice, choose to "View source" on the article while viewing it normally. Inside the HTML {{c|head}} element, near the start of the body, will be the {{c|og:image meta property}} tag. If this tag appears in the article's HTML and is non-empty, then an image has been assigned to the page. If you do not believe the image is appropriate, use of this template will override the value already in that tag. Please note that to be useful, any PageImage must be at least 200x200 pixels in size; social media sites will choose a different image if anything smaller is assigned, regardless of the tag's presence. Images larger than 1500 in width will likewise be thumbnailed and are not likely to be optimal for sharing.

An example of what a valid, useful {{c|og:image}} tag will look like:
 <nowiki>&lt;meta property="og:image" content="https://doomwiki.org/w/images/c/c7/BTSXE1.jpg" /&gt;</nowiki>

Note you can also view a report on the complete list of articles with a PageImage assigned at https://doomwiki.org/wiki/Special:PagesWithProp?propname=page_image&propname-other= but this list will eventually grow to the point of not being useful.

==Categorization==
Articles using this template will be added to the hidden {{cat|Articles with main image override}} category.

[[Category:Internal link templates]]
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