using get_template_part() inside a widget and passing variables

Indeed, get_template_part is meant to be used in themes only, though that would include widgets inside your theme. Looking at the source code of the function you’ll see that the main reason for this is that get_template_part does some extra theme related stuff before it calls locate_template in a non-default way.

That said you should have no problem calling it from a widget, so the issue most likely is that your loop.php is not in the place where WP is looking for it.

Refer to this answer for passing a variable to a template.

Related Posts:

  1. How can I use the built in WordPress “browse link” functionality?
  2. Code for Recent Posts Widget
  3. Prevent widgets removal
  4. Is there a way to add more tags to the tag cloud?
  5. Modify recent post sidebar to show post thumbs with out plugins
  6. Why Can’t wp_editor Be Used in a Custom Widget?
  7. How to listen to color changes on the color picker?
  8. Add New Footer Widget Area with Limited Options?
  9. Add div class to only one widget
  10. Updating to Version 4.5 bumped my “main sidebar” widget out of place
  11. How can I delete all inactive widgets?
  12. Call sidebar from a template
  13. Adding classes to dynamic sidebar
  14. Widget Area: Modify $param[‘xy’] from widget-$n
  15. Need help adding additional controls to a custom widget
  16. Why do none of my widgets have a title?
  17. Widget area inside a widget
  18. Defer Code in Widgets – Page Speed
  19. How to limit wp_get_archives to show months for the X years only
  20. Bolding specific word(s)/parts of widget title
  21. Adding a widget to a string of HTML
  22. Pass variables from one widget to another widget
  23. Remove the widgets tab from theme customizer
  24. Remove/Add widgets from/to the Available Widgets pool
  25. Check if widget is active
  26. Radio buttons in widget not saving
  27. How can I apply css styling to the current day in the calendar widget
  28. AJAX Contact Form Issue
  29. Including PHP files doesn’t work outside of Localhost
  30. Is there an official email form widget or block?
  31. Widget html code error
  32. Display sidebar only if it has content
  33. Post-specific widgets in WordPress ‘Twenty Fourteen’ theme
  34. Display custom widget, added as a shortcode in the correct place
  35. Dynamic sidebar based on category
  36. Show posts from one category with thumbnail and description on latest
  37. Get posts after today (upcoming events)
  38. How to pass data from page to widget functions?
  39. Adding a rich text editor to a widget – specifically CKEditor
  40. Enqueue script/style if certain widget has certain value
  41. How to display/register widget only on post pages in custom plugin
  42. Is it possible to display tag cloud widget by category?
  43. Widgets not saving values
  44. Widget page is missing from menu and default widgets are not showing
  45. wp_editor in widget breaks after save (no buttons and visual tab broken)
  46. How to use a dropdown to populate a list of post from CPT
  47. Fire on widgets_init only on dashboard
  48. Access Customizer widget instance form
  49. Registering a stylesheet inside my WordPress widget
  50. How to position custom dashboard widgets on side column
  51. One register_sidebar function works, the other doesn’t?
  52. WordPress widget title coding
  53. Text Widget in Footer for just 1 page template
  54. Modify WordPress widgets Screen
  55. How to change color of registered widget areas in admin?
  56. Filter Text from sidebar widget?
  57. How to filter widget(s) based on a specific category landing page
  58. How do I remove/reset all current widgets from the database?
  59. Search transients through widget
  60. what is the difference between these two types of widget form method
  61. Change the background color of my theme widgets
  62. Change Woocommerce Product Categories Widget ‘Title’ based on Product Category
  63. How to allow editing of text in sidebar?
  64. Creating a dynamic class name in my custom widget
  65. Want to add more option in “Sexy Login”
  66. WordPress Local to Live and The Missing Widgets!
  67. Extending the WordPress Recent Posts Widget
  68. delete widget upon uninstall
  69. How to paste widget to a specific page
  70. How do I find out which
  71. Unable to see Widget Submenu under Appearance with Class Based WP_Widget
  72. An archive widget, coming from nowhere on my posts and pages
  73. custom widget not saved to sidebar
  74. When editing in block editor, the post/article gets under the floating widgets
  75. Make widget with media upload repeatable
  76. I accidentally added a widget area called sidebar 1
  77. wp_registered_widgets doesn’t contains my widgets
  78. How Can I Replicate & Register a Widget from the Child Theme
  79. How to retrieve category ID’s from widget settings?
  80. My plugin works in home page, but doesn’t work in post page
  81. Can I use wp_widget_rss_output to show my site’s feed in the dashboard?
  82. How can I add widgets to the category page?
  83. How to create another widgets.php page
  84. Remove default WordPress widgets
  85. widget that will do shortcodes that user inputs
  86. Widget dynamically add new input field
  87. How to show widget in frontend?
  88. Widget Development – Displaying dropdown content
  89. WordPress function breaks widget’s markup?
  90. Registering multiple copies of a widget
  91. page url in shortcode
  92. iframe/embed vid in text widget loads outside container and moves around when scrolling the page?
  93. menu in different page in different style
  94. Add text to Text Widget using Javascript
  95. Widget logic not working
  96. Subpages menu on sidebar plus widgets
  97. Widgets in PHP files?
  98. Text Widget Not Working
  99. Widget block editor: Unable to collect checkbox values inside widget update() method
  100. Theme Widget Area Defaults