Creating a preview page feature in Laravel 5.1 - php

Question

I am new to Laravel and I am creating content management system as practice to get familiar with the framework. Currently, I am working on the feature for the user to preview the information they have entered for updating the new page they want to create and here is code for the view:
<div ng-controller="PagesController">
<form action="{{url('admin/page/preview')}}" method="post" name="pageForm">
<div class="col-md-9">
<div class="panel-body">
<div class="row">
<div class="form-group">
<label>Title</label>
<input type="hidden" name="_token" value="{{ csrf_token() }}">
<input type="text" class="form-control input-md" name="title" ng-model="page.title">
</div>
<!-- <input type="submit" value="Preview"> -->
</div>
<div class="row">
<div class="form-group">
<fieldset style="border: 1px solid #E4E4E4; padding-top: 5px; padding-bottom: 5px;">
<div class="form-group">
<div class="col-md-5">
<label>Add File</label>
<input type="file" name="upload" nv-file-select uploader="updateUploader" value="Select Picture" ng-model="page.upload" >
</div>
<div class="col-md-6">
<table class="table">
<thead>
<tr>
<th>Name</th>
<th>Progress</th>
<th>Actions</th>
</tr>
</thead>
<tbody>
<tr ng-repeat="item in updateUploader.queue">
<td style="max-width: 170px; word-wrap: break-word;" ng-cloak><strong>#{{ item.file.name}}</strong></td>
<td><div class="col-md-12"><progressbar value="item.progress"></progressbar></div></td>
<td nowrap ng-cloak>
<button type="button" class="btn btn-danger btn-xs" ng-click="item.remove()">
<span class="glyphicon glyphicon-trash"></span> Remove
</button>
</td>
</tr>
</tbody>
</table>
</div>
</div>
</fieldset>
</div>
</div><br>
<div class="row">
<div class="form-group">
<label>Body</label>
<input type="hidden" name="body" value="#{{page.body}}"/>
<summernote name="body" ng-model="page.body" config="options" height="300"></summernote>
<div ng-messages="pageForm.body.$error" ng-if="pageForm.body.$dirty">
<div ng-message="required">
<span class="error-msgs">Please enter page information</span>
</div>
</div>
</div>
</div>
<br/>
<div class="row">
<div class="form-group">
<div class="col-md-12 text-left">
</div>
</div>
</div>
</div>
<div class="row">
<div class="form-group">
<div class="checkbox col-md-12 text-left">
<label><input type="checkbox" value="" ng-model"page.serivice" ng-false-value="0" ng-true-value="1" ><strong>Update page to services</strong></label>
</div>
</div>
</div>
<div class="row">
<div class="form-group">
<div class="col-md-12 text-left">
<button type="button" class="btn btn-success" name="update" ng-disabled="pageForm.$invalid" ng-click="update()">Update</button>
<input type="submit" class="btn btn-default btn-md" value="Preview">
</div>
</div>
</div>
</div>
<div class="col-md-3">
<div class="panel panel-default general-panel publish" style="margin-top: 35px;">
<div class="panel-heading">
<div class="title">Navigation</div>
</div>
<div class="panel-body">
<span class="">
<i></i><strong>Parent pages</strong>
<div class="btn-group">
<select class="form-control" name="publish_period" ng-model="page.parent_nav">
<option value="">No Parent Navigation</option>
<option value="about-us">About Us</option>
<option value="media">Media</option>
<option value="publication">Publication</option>
<option value="law">Law</option>
<option value="legislation">Legislation</option>
<option value="compliance">Compliance</option>
<option value="license">Applying For License</option>
</select>
</div><br><br>
</span>
</div>
</div>
<div class="panel panel-default general-panel general-summary">
<div class="panel-body">
<table class="table">
<thead>
<tr>
<th colspan="3"><h5>Uploaded Documents</h5></th>
</tr>
</thead>
<tbody>
<tr ng-repeat="document in documents">
<td style="max-width: 100px; word-wrap: break-word;">#{{document.file_path}}</td>
<td>
<i class="fa fa-download fa-fw"></i>Download
</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</form>
</div>
Here is the code for the route for previewing the page:
Route::post('page/preview','PagesController#preview');
and the controller method for the preview function:
public function preview(Request $request)
{
return view('admin.pages.preview')->with('title',$request->input('title'))->with('body',$request->input('body'));
}
This works for me, but when I refreshed the preview page it would generate an error saying BadMethodCallException. So I am wondering how can eliminate this from happening? and thanks in advance.