How to generate a custom CSV export? - php

Question

I have a page called EventPage that I am managing via a Model admin. Also using Catalog manager: https://github.com/littlegiant/silverstripe-catalogmanager
Question is I need to be able to export all the expired events (And all of the fields).
I have an 'EndDate' => 'Date', field on the EventPage.
So I want to only show EventPages in my CSV export where the EndDate is GreaterThanOrEqual to todays date e.g Expired.
The following generates an CSV export button, but currently it is exporting all the fields, where as I want to filter it so we only show the expired events.
How do I go about this?
<?php
class EventAdmin extends CatalogPageAdmin {
public $showImportForm = false;
private static $managed_models = array(
'EventPage',
'EventCategory',
'EventSubmission',
);
private static $url_segment = 'events';
private static $menu_title = 'Events';
public function getEditForm($id = null, $fields = null) {
$form = parent::getEditForm($id, $fields);
$gridFieldName = 'EventPage';
$gridField = $form->Fields()->fieldByName($gridFieldName);
if ($gridField) {
$gridField->getConfig()->addComponent(new GridFieldExportButton());
}
return $form;
}
}

Answer 1

We can create a custom export button to filter the list of items before exporting them.
First we create a GridFieldExportExpiredEventsButton which extends GridFieldExportButton. This is a complete copy of the current SilverStripe 3.5 generateExportFileData function but with an added filterByCallback on the $items list to filter items that have an EndDate < date('Y-m-d').
class GridFieldExportExpiredEventsButton extends GridFieldExportButton {
public function getHTMLFragments($gridField) {
$button = new GridField_FormAction(
$gridField,
'export',
'Export expired events',
'export',
null
);
$button->setAttribute('data-icon', 'download-csv');
$button->addExtraClass('no-ajax action_export');
$button->setForm($gridField->getForm());
return array(
$this->targetFragment => '<p class="grid-csv-button">' . $button->Field() . '</p>',
);
}
public function generateExportFileData($gridField) {
$separator = $this->csvSeparator;
$csvColumns = $this->getExportColumnsForGridField($gridField);
$fileData = '';
$member = Member::currentUser();
if($this->csvHasHeader) {
$headers = array();
// determine the CSV headers. If a field is callable (e.g. anonymous function) then use the
// source name as the header instead
foreach($csvColumns as $columnSource => $columnHeader) {
$headers[] = (!is_string($columnHeader) && is_callable($columnHeader)) ? $columnSource : $columnHeader;
}
$fileData .= "\"" . implode("\"{$separator}\"", array_values($headers)) . "\"";
$fileData .= "\n";
}
//Remove GridFieldPaginator as we're going to export the entire list.
$gridField->getConfig()->removeComponentsByType('GridFieldPaginator');
$items = $gridField->getManipulatedList();
$items = $items->filterByCallback(function($item) {
// The following line modifies what items are filtered. Change this to change what items are filtered
return $item->EndDate < date('Y-m-d');
});
// #todo should GridFieldComponents change behaviour based on whether others are available in the config?
foreach($gridField->getConfig()->getComponents() as $component){
if($component instanceof GridFieldFilterHeader || $component instanceof GridFieldSortableHeader) {
$items = $component->getManipulatedData($gridField, $items);
}
}
foreach($items->limit(null) as $item) {
if(!$item->hasMethod('canView') || $item->canView($member)) {
$columnData = array();
foreach($csvColumns as $columnSource => $columnHeader) {
if(!is_string($columnHeader) && is_callable($columnHeader)) {
if($item->hasMethod($columnSource)) {
$relObj = $item->{$columnSource}();
} else {
$relObj = $item->relObject($columnSource);
}
$value = $columnHeader($relObj);
} else {
$value = $gridField->getDataFieldValue($item, $columnSource);
if($value === null) {
$value = $gridField->getDataFieldValue($item, $columnHeader);
}
}
$value = str_replace(array("\r", "\n"), "\n", $value);
$columnData[] = '"' . str_replace('"', '""', $value) . '"';
}
$fileData .= implode($separator, $columnData);
$fileData .= "\n";
}
if($item->hasMethod('destroy')) {
$item->destroy();
}
}
return $fileData;
}
}
The extra line that we have added that filters the export items is:
return $item->EndDate < date('Y-m-d');
Alter this to alter the list of items that are exported. I have set this to only return items which have an EndDate that is in the past. Change this as you need.
We then add this export button to our grid field in our event model admin:
class EventAdmin extends CatalogPageAdmin {
private static $managed_models = array(
'EventPage'
);
public function getEditForm($id = null, $fields = null) {
$form = parent::getEditForm($id);
if ($this->modelClass == 'EventPage') {
$gridField = $form->Fields()->fieldByName($this->modelClass);
$gridField->getConfig()->removeComponentsByType('GridFieldExportButton');
$gridField->getConfig()->addComponent(new GridFieldExportExpiredEventsButton('buttons-before-left'));
}
return $form;
}
}

Answer 2

This was originally two answers...
To limit the fields
Have you had a look at the GridFieldExportButton class ?
The constructor
/**
* #param string $targetFragment The HTML fragment to write the button into
* #param array $exportColumns The columns to include in the export
*/
public function __construct($targetFragment = "after", $exportColumns = null) {
$this->targetFragment = $targetFragment;
$this->exportColumns = $exportColumns;
}
So you should be able to pass $exportColumns as an argument.
in your code that would be
if ($gridField) {
$gridField->getConfig()->addComponent(new GridFieldExportButton("after", ["field1", "field2"]));
}
OR - EVEN BETTER SOLUTION
you can define your summary fields on EventPage as such
private static $summary_fields = ["FIeld1", "Field2"];
Then make sure your flush and it should use that as fields.
To filter which items to export in your CSV
So in this case, I think you should create a new class that extends GridFieldExportButton (maybe called EventPageCSVExportButton or something) and override the methods you want. In your case it would probably be generateExportFileData(), just do a check in the loop and exclude data you don't want.
Then use that new class in your EventAdmin.

Answer 3

Have you had a look at the GridFieldExportButton class ?
The constructor
/**
* #param string $targetFragment The HTML fragment to write the button into
* #param array $exportColumns The columns to include in the export
*/
public function __construct($targetFragment = "after", $exportColumns = null) {
$this->targetFragment = $targetFragment;
$this->exportColumns = $exportColumns;
}
So you should be able to pass $exportColumns as an argument.
in your code that would be
if ($gridField) {
$gridField->getConfig()->addComponent(new GridFieldExportButton("after", ["field1", "field2"]));
}
OR - EVEN BETTER SOLUTION
you can define your summary fields on EventPage as such
private static $summary_fields = ["FIeld1", "Field2"];
Then make sure your flush and it should use that as fields.