Using Template Tag Functions in a block

  • Resolved Martin Taylor

    (@docdunning)


    3 years, 12 months ago

    Reporting an issue when using a template tag function in a WP block.

    I’ve created a custom block that uses tablepress_print_table() to display a table, according to some parameters that the user enters for the block. This is an alternative to the shortcode that TablePress provides.

    If I add the block to a post/page in the editor, it works fine and displays the table as expected. Now I publish the post and it looks good on the front end.

    Problem – when I then go to edit the post/page, WordPress crashes “Fatal error: Uncaught Error: Call to undefined function tablepress_print_table() …”

    After some investigation, I’ve found that WP invokes the block more than once when it starts up the editor. I added some code to my block and to the TablePress run() function to output a trace to a file. Here’s what I get when I click to edit the page.

    In TablePress function run() - Controller selected: admin_ajax
In TablePress function run() - Controller selected: admin
In TablePress function run() - Controller selected: admin_ajax
In TablePress function run() - Controller selected: admin
In Block render - function does not exist <strong>(Could crash here)</strong>
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In Block render - function found OK
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In Block render - function found OK
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: frontend
In TablePress function run() - Controller selected: admin_ajax
In TablePress function run() - Controller selected: admin
In TablePress function run() - Controller selected: admin_ajax

    So in my block code, I have to use if (function_exists('tablepress_print_table') because when it’s first invoked, TablePress is using the “admin” controller.

    I have to say that I’m very surprised that the block is called up three times, and that TablePress is called in so many times, just when I click to edit a page!

    As I say, this is mainly to report the issue so that others can be aware. I am OK with the workaround, which is to use if (function_exists('tablepress_print_table') in my block – then it works and displays the table in the editor as I want it to.

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  • Plugin Author Tobias B?thge

    (@tobiasbg)

    Hi,

    thanks for your post, and sorry for the trouble.

    It’s indeed very interesting, that TablePress apparently is called that often for the block. I have no clue why that is, but I don’t have experience with developing blocks yet.

    Now, that error is essentially the result of a design decision from the early days of TablePress: The Shortcode and Template Tag functions are only loaded in the frontend context, as I couldn’t think of a scenario where they would be needed in the admin area – there was no thought of an editor like Gutenberg back then. This design decision could probably be reverted, but I’m a bit afraid of potential issues with backward compatibility.

    So, that solution that you found looks totally fine here, as it should not be necessary to evaluate the Shortcode in the block editor. Nice find!

    Best wishes,
    Tobias

Viewing 1 replies (of 1 total)
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