Custom Validation
>>> [!note] Migrated issue
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Reported by: [iLLin](https://www.drupal.org/user/384543)
>>>
<p>The only way I have found to do custom validation on field collections is by prepending a validation hook to the element_validate property of the widget. Below is an example on how I did this.</p>
<div class="codeblock">
<pre><span style="color: #000000"><span style="color: #0000BB"><?php<br></span><span style="color: #FF8000">/*<br> * Adds a validation hook to the beginning of the #element_validate<br> * to provide custom validation on the required fields within the<br> * widget.<br> */<br></span><span style="color: #007700">function </span><span style="color: #0000BB">trip_planner_field_widget_form_alter</span><span style="color: #007700">(&</span><span style="color: #0000BB">$element</span><span style="color: #007700">, &</span><span style="color: #0000BB">$form_state</span><span style="color: #007700">, </span><span style="color: #0000BB">$context</span><span style="color: #007700">) {<br> switch (</span><span style="color: #0000BB">$context</span><span style="color: #007700">[</span><span style="color: #DD0000">'instance'</span><span style="color: #007700">][</span><span style="color: #DD0000">'widget'</span><span style="color: #007700">][</span><span style="color: #DD0000">'type'</span><span style="color: #007700">]) {<br> case </span><span style="color: #DD0000">'field_collection_embed'</span><span style="color: #007700">:<br> </span><span style="color: #FF8000">// @todo check for field name<br> </span><span style="color: #0000BB">array_unshift</span><span style="color: #007700">(</span><span style="color: #0000BB">$element</span><span style="color: #007700">[</span><span style="color: #DD0000">'#element_validate'</span><span style="color: #007700">], </span><span style="color: #DD0000">'trip_planner_validate_line_item'</span><span style="color: #007700">);<br> break;<br> }<br>}<br><br></span><span style="color: #FF8000">/*<br> * Validate our from and to destinations from our field collection<br> * widget. We need to use form_error on each field to fire off the<br> * necessary errors.<br> */<br></span><span style="color: #007700">function </span><span style="color: #0000BB">trip_planner_validate_line_item</span><span style="color: #007700">(</span><span style="color: #0000BB">$element</span><span style="color: #007700">, &</span><span style="color: #0000BB">$form_state</span><span style="color: #007700">, </span><span style="color: #0000BB">$form</span><span style="color: #007700">) {<br> </span><span style="color: #0000BB">form_error</span><span style="color: #007700">(</span><span style="color: #0000BB">$form</span><span style="color: #007700">[</span><span style="color: #DD0000">'field_from_to'</span><span style="color: #007700">][</span><span style="color: #0000BB">LANGUAGE_NONE</span><span style="color: #007700">][</span><span style="color: #0000BB">0</span><span style="color: #007700">][</span><span style="color: #DD0000">'field_tee_time'</span><span style="color: #007700">], </span><span style="color: #DD0000">'test'</span><span style="color: #007700">);<br>}<br></span><span style="color: #0000BB">?></span></span></pre></div>
<p>If you have unlimited values, you will need to iterate over your container (which I will be doing next if anyone is interested). The reason why it needs to be done this way is because the function field_collection_field_widget_embed_validate() validates and submits all in once, so if you add a validation hook anywhere else, except before this function, it just gets ignored.</p>
issue
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Project: project/field_collection
Instance: https://git.drupalcode.org
Before proposing or making any changes, READ each of these files and FOLLOW their guidance:
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Repository: https://git.drupalcode.org/project/field_collection
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