Question

我正在开发一个图书馆系统，Octobercms，我需要限制每笔贷款的最大书籍数量，例如：2。这样当你达到选择的数量时，不要让我选择更多的书籍那笔贷款。

请帮助我！

Answer 1

为了使其工作，我们需要different approach，instead adding error when we are selecting我们可以抛出错误when saving，（因为添加java脚本有点难以及其客户端如此不安全）

只需将此code添加到您的controller和change fields according to need。

public function onRelationManageAdd() {
    $checked = \Input::get('checked');
    $field = \Input::get('_relation_field');
    $maximumAllowed = 2;
    // i have used comment $field you need to replace it with your field
    // this will be your hasMany relational field name
    // also added condition to check selected id is more then 2
    if($field == 'comments' && is_array($checked) && count($checked) > $maximumAllowed) {

        // if selected id is more then 2 we add flash error and return blank array
        \Flash::error('You Can Select Only 2 !');
        return [];
    }

    // ADDITIONAL CHECK if you need more check you can add it here and return error
    if($field == 'comments' && isset($this->params[0])) {
        // currently editing record id.
        $currentEditRecordId = $this->params[0];
        $record = \October\Test\Models\Post::find($currentEditRecordId);
        if($record && $record->comments->count() >= $maximumAllowed) {
            \Flash::error('You Can Select Only 2 !');
            return [];
        }
    }

    // if everything is good then handle request by relation manger 
    //and return response
    return $this->asExtension('RelationController')->onRelationManageAdd();
}

我添加了ADDITIONAL CHECK，因为这会允许用户select 2 records per one time，但是用户可以select 2 records multiple time，但我们不允许这样做;）

您可以添加自己喜欢的custom validations。

更新

问题：第一次选择1条记录，然后选择另一条记录 - 解决方案

public function onRelationManageAdd() {
    $checked = \Input::get('checked');
    $field = \Input::get('_relation_field');

    $maximumAllowed = 2;
    $count = 0;

    // i have used comment $field you need to replace it with your field
    // this will be your hasMany relational field name
    // also added condition to check selected id is more then 2
    if($field == 'comments' && is_array($checked)) {
        //$count += count($checked);            
        $count = $count + count($checked);         
    }

    // ADDITIONAL CHECK if you need more check you can add it here and return error
    if($field == 'comments' && isset($this->params[0])) {
        // currently editing record id.
        $currentEditRecordId = $this->params[0];
        $record = \October\Test\Models\Post::find($currentEditRecordId);
        if($record) {
            $count = $count + $record->comments->count();
        }
    }

    if($count > $maximumAllowed) {

        // if selected id is more then 2 we add flash error and return blank array
        \Flash::error('You Can Select Only 2 !');
        return [];
    }

    // if everything is good then handle request by relation manger 
    //and return response
    return $this->asExtension('RelationController')->onRelationManageAdd();
}

信息：您可以将此relational field in update context添加为用户adding new record作为当前记录we don't have information for current record的时间is not saved yet，relation count 第二次检查和validation will fail 。

以避免此问题您可以为该字段添加更新上下文，该字段仅在update中可用。

banner: label: Banner oc.commentPosition: '' mode: file span: auto type: mediafinder context: update <------ add this option

现在此字段仅在用户保存记录时显示。我们现在对验证很满意。

如果您收到任何错误，请发表评论。

Octobercm后端列出选择的最大限制

1 个答案:

更新