GooglePlace AutoComplete on RadTextBoxControl

[Jean-Charles]

Private Sub AddAutoCompleteItems()

     Me.RadTextBoxControl1.AutoCompleteMode = AutoCompleteMode.Suggest
     Dim resultgoogle As RadListDataItemCollection = RadTextBoxControl1.AutoCompleteItems
     Dim value As String = RadTextBoxControl1.Text
     Dim url As String = "https://maps.googleapis.com/maps/api/place/autocomplete/json?input=" & value & "&types=establishment&language=fr&key=YOURAPIKEY"
     Dim request As WebRequest = WebRequest.Create(url)
     Dim response As HttpWebResponse = request.GetResponse()
     Dim responseStream As Stream = response.GetResponseStream()
     Dim reader As New StreamReader(responseStream)
     Dim jsonData As String = reader.ReadToEnd()
     Dim jResults As JObject = JObject.Parse(jsonData)
     Dim data As List(Of JToken) = jResults.Children().ToList

     reader.Close()

     For Each item As JProperty In data
         item.CreateReader()
         Select Case item.Name
             Case "predictions"

                 For Each msg As JObject In item.Values
                     If resultgoogle.Contains(msg("description")) Then
                         'nothing
                     Else
                         resultgoogle.Add(New RadListDataItem(msg("description")))
                     End If
                 Next
         End Select
     Next

     If RadTextBoxControl1.Text = "" Then
         resultgoogle.Clear()
     End If

 End Sub

 Private Sub RadTextBoxControl1_TextChanged(sender As Object, e As EventArgs) Handles RadTextBoxControl1.TextChanged
     AddAutoCompleteItems()
 End Sub

 

If you have a more efficient solution to limit requests on the google API, do not hesitate to share.

 

JC

[Dess | Tech Support Engineer, Principal]

Hello, Jean-Charles,   

According to the provided code snippet it seems to be a solution for populating the autocomplete items in RadAutoCompleteBox while you are typing. We have a Knowledge Base article introducing a similar approach but for RadDropDownList. You can simply hide the arrow button and leave only the editable part. Here is the article for your reference: https://www.telerik.com/support/kb/winforms/dropdown-checkeddropdown-and-list/details/server-side-auto-complete-for-raddropdownlist

I hope this information helps. If you have any additional questions, please let me know.  

 

Regards,
Dess
Progress Telerik

[Jean-Charles]

Hi Dess,

This code is beautiful and breathes the performance!
An help to adapt it to my need would be welcome.

 

JC

[Dess | Tech Support Engineer, Principal]

Hello, Jean-Charles,    

In order to reduce the requests on the google API, you can extract all items once when loading the application and store the records in an appropriate collection. Thus, when changing the text in the control you have chosen, you can use the already stored collection and don't extract any information from google.

The referred KB approach is applicable only for RadDropDownList because it has a completely different implementation compared to RadAutoCompleteBox. Hence, if you need to use the approach from the KB, feel free to use a RadDropDownList and simply set the hide the arrow by setting the DropDownListElement.ArrowButton.Visibility property to Collapsed. Otherwise, use the RadAutoCompleteBox and cache all records when loading the application in order to reduce the requests.

I hope this information helps. If you have any additional questions, please let me know.  

 

Regards,
Dess
Progress Telerik