====== Insert Answer Texts in Follow-up Questions ======

[[::en:create:Placeholders|Placeholders]] allow you to use participants‘ text inputs elsewhere in the questionnaire. This chapter provides you with a number of examples.
 
**Note:** If in a follow-up question you only want to display specific scale items or select options dependent on the participant’s response, please refer to [[:en:create:filter-items]].

**Note:** If you haven’t worked with filters and PHP code, please refer to chapters [[:de:create:php]] and [[:de:create:filter-solving]] first.


===== Use Single Answers =====

On page 2 the participant mentioned the name of a TV presenter in a text input field (tagging ''TX01_01''). Answer validation was applied to ensure the participant did enter something. The entered name is now to be included in following question texts or scale items. 

In the first step, create a placeholder ''[[:en:create:functions:replace]]'' for the name, e. g. ''%presenter%''. In order to do so, place the following PHP code on a page of the questionnaire following the text input question (e. g. in the example on page 3 or later):

<code php>
replace('%presenter%', 'TX01_01', 'response');
</code>

This placeholder can then be inserted anywhere in the questionnaire -– of course, only after it was created via PHP code. For example, the question text of a question on page 3 could be as follows:

<code>
Please assess <strong>%presenter%</strong> with regard to the following characteristics.
</code>

**Note:** It is not possible to use ''replace()'' to display the participant’s entry immediately on the same page of the questionnaire. This function would require [[:en:create:javascript|JavaScript]].

**Note:** In order to check if the placeholder functions correctly, you need to re-start the questionnaire from the beginning – or at least from the page with the text input field where the relevant name was entered (in the example on page 2).

**Tip:** Once a placeholder has been created, it remains valid for any following pages in the questionnaire. Repeating the PHP code on every page is __not__ required. 

**Tip:** The above described PHP code also allows you to enter predefined answers (e.g. from a multi-choice question) in follow-up questions.

**Tip:** As an alternative, the participant’s entry can be read out via ''[[:en:create:functions:value]]'' and subsequently be transferred to ''[[:en:create:functions:replace]]''.

<code php>
$name = value('TX01_01');
replace('%presenter%', $name);
</code>

===== Insert Several Answer Texts =====

A question of the question type "Text Input" (''TX01'') __or__ "Free Mention" (''TX02'') is presented to the participant. Up to 10 answers can be chosen. In a follow-up question (e. g. multiple selection, rank, scale) the answers are to be displayed as items or options. 

The problem in this example is that the participant might complete only part of the input fields. Consequently, the follow-up questions must only display the relevant items/options. Also, it would mean a lot of extra work to write ''redirect()'' 10 times. A for-loop handles the iteration.

In order for the follow-up question to function (e. g. ''FQ01'') properly, create that question as follows: The number of items/options in the question must equal the number of possible text inputs (in the example: 10), and texts used for the items/options are placeholders, e. g. ''%text1%'' to ''%text10%''.

<code>
%text1%
%text2%
%text3%
%text4%
%text5%
%text6%
%text7%
%text8%
%text9%
%text10%
</code>

**Tip:** Of course, additional text may be added to the placeholders, e. g. "evaluation %text1%".

Via ''[[:en:create:functions:value]]'' the following PHP code reads out all of  the ten possible text input fields, checks if an entry has been made, creates the placeholders ''%text1%'' to ''%text10%'' and displays question FQ01 with the matching items/options.

**Important:** The PHP codes for “Text Input“ and “Free Mention” differ slightly in line 4, because the variables are determined according to different patterns (''TX01_01'' vs. ''TX02x01'').

^Text Input^Free Mentions^
|<code php>
$question = 'TX01';
$items = array();
for ($i=1; $i<=10; $i++) {
  $itemID = $question.'_'.sprintf('%02d', $i);
  $answer = value($itemID);
  if (trim($answer) != '') {
    replace('%text'.$i.'%', $answer);
    $items[] = $i;
  }
}
// Folgefrage anzeigen
if (count($items) > 0) {
  question('FF01', $items);
}
</code>|<code php>
$question = 'TX02';
$items = array();
for ($i=1; $i<=10; $i++) {
  $itemID = $question.'x'.sprintf('%02d', $i);
  $answer = value($itemID);
  if (trim($answer) != '') {
    replace('%text'.$i.'%', $answer);
    $items[] = $i;
  }
}
// Folgefrage anzeigen
if (count($items) > 0) {
  question('FF01', $items);
}
</code>|

Explanatory note on the PHP code: The IF filter at the end ensures that the follow-up question is skipped if the participant has not completed the relevant field. Through ''trim()'' blank spaces at the beginning and end of the text entered are removed so that a number of blanks entered into a text field are not interpreted as a valid answer.  Through ''sprintf()'' with its parameter '''%02d''' it is ensured that numbers are displayed as double-digits with leading zeros (e. g. ''01'' instead of ''1'').

**Note:** If the PHP code does not provide the required results, please refer to chapter [[:en:create:filter-solving]].

