Category: Programming

reCAPTCHA is a free service that protects your website from spam and abuse. reCAPTCHA uses an advanced risk analysis engine and adaptive CAPTCHAs to keep automated software from engaging in abusive activities on your site. It does this while letting your valid users pass through with ease.

First, we do have to register a Google API key for our WebApp here.

After registering, we receive our API key:
For this demo, I’m using the developer API key (which works with localhost) so it will show a warning that this is not the real key in red.
NOTE: this code is for ABMaterial 3.75. For earilier versions, see below what needs to be changed in the code.

Create a new class CompReCAPTCHA:

'Class module
Sub Class_Globals
   Public ABMComp As ABMCustomComponent
   Dim mAPIKey As String
End Sub

'Initializes the object. You can add parameters to this method if needed.
Public Sub Initialize(InternalPage As ABMPage, ID As String, APIKey As String)
   ABMComp.Initialize("ABMComp", Me, InternalPage, ID, "")
   mAPIKey = APIKey
End Sub
Sub ABMComp_Build(InternalPage As ABMPage, internalID As String) As String
   Return $"
<div id="${internalID}render" class="g-recaptcha" data-sitekey="${mAPIKey}"></div>
"$
End Sub
' Is useful to run some initalisation script.
Sub ABMComp_FirstRun(InternalPage As ABMPage, internalID As String)
   Dim script As String = $"grecaptcha.render(
"${internalID}render",
{"sitekey": "${mAPIKey}", "theme": "light"}
) "$
   InternalPage.ws.Eval(script, Array As Object(ABMComp.ID))
   ' flush not needed, it's done in the refresh method in the lib
End Sub

public Sub Reset(InternalPage As ABMPage)
   Dim script As String = $"grecaptcha.reset()"$
   InternalPage.ws.Eval(script, Null)
   InternalPage.ws.Flush
End Sub

public Sub CheckValidation(InternalPage As ABMPage) As Boolean
   Dim script As String = $"return (grecaptcha && grecaptcha.getResponse().length !== 0);"$
   Dim ret As Future = InternalPage.ws.EvalWithResult(script, Null)
   InternalPage.ws.Flush

   Return ret.Value
End Sub
' runs when a refresh is called
Sub ABMComp_Refresh(InternalPage As ABMPage, internalID As String)
   Dim script As String = $""$
   InternalPage.ws.Eval(script, Array As Object(ABMComp.ID))
End Sub
' do the stuff needed when the object is removed
Sub ABMComp_CleanUp(InternalPage As ABMPage, internalID As String)
End Sub

In BuildPage(), add the Google api:

page.AddExtraJavaScriptFile("<a class="linkification-ext" title="Linkification: https://www.google.com/recaptcha/api.js" href="https://www.google.com/recaptcha/api.js">https://www.google.com/recaptcha/api.js</a>")

In Class_Globals make a variable:

Dim myReCAPTCHA As CompReCAPTCHA

In ConnectPage create the component (and a couple of buttons):

...
' note that this is Googles demo API key.  Use your own!
myReCAPTCHA.Initialize(page, "myReCAPTCHA", "6LeIxAcTAAAAAJcZVRqyHh71UMIEGNQ_MXjiZKhI")
page.Cell(1,1).AddComponent(myReCAPTCHA.ABMComp)

Dim btn As ABMButton
btn.InitializeFlat(page, "btn", "", "", "Submit", "")
page.Cell(1,1).AddComponent(btn)

Dim btn2 As ABMButton
btn2.InitializeFlat(page, "btn2", "", "", "Reset", "")
page.Cell(1,1).AddComponent(btn2)

' refresh the page
page.Refresh
...

The code in the buttons to check its validation and to reset the captcha.

Sub btn_Clicked(Target As String)
   Dim bool As Boolean = myReCAPTCHA.CheckValidation(page)
   Log(bool)
End Sub

Sub btn2_Clicked(Target As String)
   myReCAPTCHA.Reset(page)
End Sub

Et voila, we do have a new reCAPTCHA component at our disposal in ABMaterial!

For ABMaterial pre 3.75, make these changes in the code:

Public Sub Initialize(InternalPage As ABMPage, ID As String, APIKey As String)
   ABMComp.Initialize("ABMComp", Me, InternalPage, ID) ' last param removed
   mAPIKey = APIKey
End Sub
...
Sub ABMComp_Build( internalID As String) As String ' InternalPage param removed
   Return $"
<div id="${internalID}render" class="g-recaptcha" data-sitekey="${mAPIKey}"></div>
"$
End Sub

Until next Time!

Alwaysbusy

Click here to and support ABMaterial

I recently had a question if it was possible to create a Facebook-like WebApp with ABMaterial for B4J. I had some time to spare tonight (yeah right) and decided to give it a go…

All I needed were a couple of ABMContainers and the new CloseContent/OpenContent feature introduced in 3.02. The existing NextContent system would provide the infinite page.

It also uses a ABMCustomComponent for the ‘Like’ feature (I based it on this project), and you can find the source code of the class under the video:

About an hour, and 200 lines of B4J code later, I had a working timeline!  A real project would of course need some way to add an article, save them in the database, user management, etc but this is out of scope of this article.

Note: This example will be included in the upcoming 3.02 Maintenance Update, but I would like to share the source source code for the ‘Like’ functionality beforehand.

Source code for the ‘Like’ custom component.
You’ll need this zip file for the images and js/css files. Put the images and css in the /www/css/custom folder, the js file in the /www/js/custom/ folder.

The class LikeComponent:

'Class module
Sub Class_Globals
   Public ABMComp As ABMCustomComponent
   Public Counter As Int
End Sub

'Initializes the object. Countries and data are Json Strings
Public Sub Initialize(InternalPage As ABMPage, ID As String, AlreadyLiked As Int)
   ABMComp.Initialize("ABMComp", Me, InternalPage, ID)
   Counter = AlreadyLiked
End Sub

Sub ABMComp_Build(internalID As String) As String
   Return $"
<div id="${internalID} class="facebook-reaction"><!-- container div for reaction system -->
        <span class="like-btn"> <!-- Default like button -->
          <span class="like-btn-emo like-btn-default"></span> <!-- Default like button emotion-->
           <span class="like-btn-text">Like</span> <!-- Default like button text,(Like, wow, sad..) default:Like  -->
<ul class="reactions-box"> <!-- Reaction buttons container-->
	<li class="reaction reaction-like" data-reaction="Like"></li>
	<li class="reaction reaction-love" data-reaction="Love"></li>
	<li class="reaction reaction-haha" data-reaction="HaHa"></li>
	<li class="reaction reaction-wow" data-reaction="Wow"></li>
	<li class="reaction reaction-sad" data-reaction="Sad"></li>
	<li class="reaction reaction-angry" data-reaction="Angry"></li>
</ul>
</span>
<div class="like-stat"> <!-- Like statistic container-->
           <span class="like-emo"> <!-- like emotions container -->
             <span class="like-btn-like"></span> <!-- given emotions like, wow, sad (default:Like) -->
           </span>
           <span class="like-details">${Counter} others</span></div>
</div>
"$
End Sub

Sub ABMComp_FirstRun(InternalPage As ABMPage, internalID As String)
   Dim script As String = $"$("#${internalID} .reaction").on("click",function(){  // like click
     var data_reaction = $(this).attr("data-reaction");
     $("#${internalID} .like-details").html("You and ${Counter} others");
     $("#${internalID} .like-btn-emo").removeClass().addClass('like-btn-emo').addClass('like-btn-'+data_reaction.toLowerCase());
     $("#${internalID} .like-btn-text").text(data_reaction).removeClass().addClass('like-btn-text').addClass('like-btn-text-'+data_reaction.toLowerCase()).addClass("active");;

     if(data_reaction == "Like") {
         $("#${internalID} .like-emo").html('<span class="like-btn-like"></span>');
     } else {
         $("#${internalID} .like-emo").html('<span class="like-btn-like"></span><span class="like-btn-'+data_reaction.toLowerCase()+'"></span>');
     }
     var json = {'target': '${internalID}', 'like': data_reaction};
     b4j_raiseEvent('likecomponent_liked', json);
     });    

     $("#${internalID} .like-btn-text").on("click",function(){ // undo like click
     if($(this).hasClass("active")){
       $("#${internalID} .like-btn-text").text("Like").removeClass().addClass('like-btn-text');
       $("#${internalID} .like-btn-emo").removeClass().addClass('like-btn-emo').addClass("like-btn-default");
       $("#${internalID} .like-emo").html('<span class="like-btn-like"></span>');
       $("#${internalID} .like-details").html("${Counter} others");
       var json = {'target':'${internalID}'};
         b4j_raiseEvent('likecomponent_unliked', json);
       }
     })"$

   InternalPage.ws.Eval(script, Array As Object(ABMComp.ID))
   ' flush not needed, it's done in the refresh method in the lib
End Sub

Sub ABMComp_Refresh(InternalPage As ABMPage, internalID As String)

End Sub

' do the stuff needed when the object is removed
Sub ABMComp_CleanUp(InternalPage As ABMPage, internalID As String)

End Sub

Usage:

Sub Class_Globals
   ...
   Dim myLike As LikeComponent
   ...
End Sub

' adding the component
myLike.initialize(page, ID & "Like", Rnd(20, 500))
myContainer.Cell(4,1).AddComponent(myLike.ABMComp)

Events (the name LikeComponent is set in the FirstRun() method of the class:

public Sub LikeComponent_Liked(value As Map)
   Log(value.Get("like") & " ----> " & value.Get("target"))
End Sub

public Sub LikeComponent_UnLiked(value As Map)
   Log("Unliked ----> " & value.Get("target"))
End Sub

Et voila,  a nice little demonstration of what you can make using B4J and ABMaterial.

I’ll end with a little word of advice:

If you only plan to learn one programming language this year, B4X is definitely the one you should pick!  With ABMaterial, I give you the power to write responsive, professional WebApps, and with the other B4X tools you write native Android, iOS, Desktop (Mac, Windows, Linux), Raspberry Pi and Arduino apps.  All with the same language!  You’ll wonder why you ever bothered looking at all those other pricy programming tools out there…

Happy programming!

Alwaysbusy

Click here to and get the latest ABMaterial first!