How to add content to wordpress loops? - php

Question

I've got some if statements for my plugin that I would like to execute for every post.
For now, lets just say I want to add "Hello World" to every post
I've tried quite a few things, but I can't quite seem to figure this out.
Quite simply, in my plugin I have:
add_filter('the_post','testing');
function testing($content){
echo "Hello World";
}
Obviously I'm doing something wrong as Hello World doesn't how.
Can anyone point me in the right direction please?
Here is the working code on my index.php page of my theme:
http://pastebin.com/xd1ree8W
Id' like to put the if statement at the top, within a function in my plugin, so it loads for every post.

Answer 1

So this works on my install using it in the functions.php
i didnt modify the get_the_ID() parts but you could easily use the object like so $obj->ID
function everypost_func($obj){
echo 'This is sort of cool';
if (get_post_meta(get_the_ID(), 'other-link', true))
{
$url = get_post_meta(get_the_ID(), 'other-link', true);
$status = 200;
$price = NULL;
//echo "Looks like you've got other-link selected";
}
elseif (get_post_meta(get_the_ID(), 'generic-asin', true))
{
$status = 100;
$asin = get_post_meta(get_the_ID(), 'generic-asin', true);
//echo "Looks like you've got a generic-asin";
if($_COOKIE['countrycode'] == "GB")
{
$reg = "co.uk";
//echo "and we've detected you're in the UK <br>";
}
else
{
$reg = "com";
//echo "and we've detected you're not from the UK <br>";
}
}
else
{
if(($_COOKIE['countrycode'] == "GB") && get_post_meta(get_the_ID(), 'link-uk', true))
{
$asin = get_post_meta(get_the_ID(), 'link-uk', true);
$reg = "co.uk";
$status = 100;
//echo "looks like you're in the UK, and we have a UK link<br>";
}
elseif (get_post_meta(get_the_ID(), 'link-us', true))
{
$asin = get_post_meta(get_the_ID(), 'link-us', true);
$reg = "com";
$status = 100;
//echo "looks like you're not in the UK, but we have a US link for you<br>";
}
elseif (get_post_meta(get_the_ID(), 'link-uk', true)) {
$asin = get_post_meta(get_the_ID(), 'link-uk', true);
$reg = "co.uk";
$status = 100;
//echo "looks like you're not the UK, but we have a UK link<br>";
}
else
{
$status = 404;
//echo "looks like nothing is here for you<br>";
}
}
if($status == 100)
{
$results = get_aws_details($reg, $asin);
$price = $results[0][0];
$url = $results[1][0];
$wishlist = $results[2][0];
//echo "Success";
}
elseif($status == 404)
{
$price = NULL;
$url = get_the_permalink();
$wishlist = NULL;
//echo "404";
}
}
add_action('the_post','everypost_func');
So taking in consideration that you are doing it in a plugin it will depend on the context you are constructing it.
Example in OOP : add_action('the_post',array($this,'everypost_func'));
Maybe try to make it work within the theme file ie functions.php then if it works as you are expecting it then move it in your plugin surrounded with all the goodies necessary.
-- will update more upon OP commentary

Answer 2

You have used perfects filter for the add content but you have make slightly mistake in filter function.
here you have need add "hello word" in content. bellow filter fulfilled your requirement.
function testing($content){
return $content. "Hello World";
}
add_filter('the_post','testing');
here Hello world add on beginning of the content.
I hope it's work for you.

Answer 3

When I read the headline I thought the following snippet might be what you are looking for. This supposes that your chosen theme uses the
the_content()
function to render the post content. After browsing through your paste bin I'm not so sure if this snippet addresses the code you put in the paste bin, but I'm leaving it on as it does answer the headline and might point you in the right direction.
add_filter( 'the_content', 'add_my_content' );
function add_my_content( $content ) {
return "Hello World, \n" . $content;
}