PHP Variable echo and WP-JSON

  • Ibby

    (@ibby)


    7 years, 7 months ago

    I am building a mobile application and I am trying to use WP REST API for the first time. My apologies if this has been answered many times before but my search brought no results unfortunately.

    I have a custom theme page template which has a SQL database call for some information and stores this in an array. It then processes the array and stores all of the array data into independent variables which are then echoed onto the page. This works fine on the website, but when I attempt to grab the variable outputs using the JSON URL, none of the echoed data is shown. I am aware that associative arrays and custom objects cannot be held by the REST API and this is why I stored the outputs into local variables.

    Can someone explain why this is not working please?

    //Return the details for this month
$db=dbConnect(); // Connect to database
$thisday = date("Ymd");

$query="select GregDate, aa, bb, cc from aaTimes where GregDate=$thisday";

$result = mysql_query($query);
$num_rows = mysql_num_rows($result);
$aaSTR="";

while($rs = mysql_fetch_array($result)) {
	$GregDate=$rs[0];
	$Aa=$rs[1];
	$Bb=$rs[2];
	$Cc=$rs[3];
}

echo mysql_error();
dbClose($db);

echo "<p>$Aa</p>";
echo "<p>$Bb</p>";
echo "<p>$Cc</p>";

    Thanks in advance.

Viewing 6 replies - 1 through 6 (of 6 total)
  • Joy

    (@joyously)

    7 years, 7 months ago

    This code is the PHP in the theme tempplate file. There is nothing related to the REST API or JSON.

    Dion

    (@diondesigns)

    7 years, 7 months ago

    If the above code is built into your theme, then I don’t think the REST API has the ability to execute it.

    Is there a specific reason why you’re outputting the error status of the query? That doesn’t seem necessary. More concerning, however, is that you’re using mysql functions as opposed to mysqli functions.

    Also, if the database that contains the aaTimes table can be accessed by the DB user in your WordPress installation, you should use the database access built in to WordPress. Opening another DB connection should be avoided if at all possible.

    Thread Starter Ibby

    (@ibby)

    7 years, 7 months ago

    @joyously, sorry my mistake for not explaining fully, that code is placed in the page body area to output the variables onto the actual page. It is those HTML outputs I want to make available via the REST API.

    @diondesigns, I am converting all of my code to mysqli, so this will be fixed. Would the REST API not be able to output the echos in this case? The error status was just for debug and I should have deleted it.
    Also what you said at the end there has peaked my attention; how do I use the built-in db access available to WP? I am not very experienced with WP-PHP though I knnow my way around. I usually just define a function for the db connection and then call the connection when required. It sounds like I’m doing it wrong from what you said.

    Dion

    (@diondesigns)

    7 years, 7 months ago

    I don’t think you understand how the REST API works. Your code would need to be in a function, the endpoint you define must call that function, and the output should be JSON, not HTML. It honestly sounds like what you want is an AJAX handler.

    If your custom table is accessible by the WordPress DB user, then you can use the following code:

    global $wpdb;
$dbh = $wpdb->__get('dbh');

    The $dbh variable will contain the connection handle (called link identifier in the PHP documentation), which is needed for most mysqli procedural functions. If you use this code, make absolutely certain you do not close the DB connection, or bad things will happen. 🙂

    Moderator bcworkz

    (@bcworkz)

    7 years, 7 months ago

    You can use the global $wpdb object which contains the default WP DB connection to communicate with and run queries on the DB server.

    What you do on a template file is completely irrelevant to a mobile app (unless your app has a built-in HTML interpreter :)). PHP is not even the correct programming language. The REST API can only handle standard WP objects by default. It will not give you custom data unless you add your own REST route and endpoints. Which would be in such a case written in PHP via a plugin.

    Alternately, manage your data through WP objects like a post object’s meta data. Be aware that meta data queries are very inefficient. For optimal performance, custom route and endpoints (which run queries through global $wpdb) will be preferable.

    Thread Starter Ibby

    (@ibby)

    7 years, 6 months ago

    Honestly, I actually had no idea WP had an in-built class for database connections. Thank you very much to everyone.

    I will try to do it this way and create a function which calls the variables Aa, Bb and Cc and see if I get an output in the JSON.

Viewing 6 replies - 1 through 6 (of 6 total)

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