Monthly Archives: September 2017

B4J: Creating a Star Rating component in ABMaterial

StarRating

Michał asked me in the feedback app to implement some kind of Star Rating component. As this is not so commonly needed, I thought this could be another good example of an ABMCustomComponent. One can ‘hover’ over the stars to set its value or it can be set and retrieved by code.

I show you how to do it in ABMaterial 3.75 first with the new features (released soon), and will then explain what needs to be changed for previous versions.

So let’s get started!

1. We create a new standard class CompStarRating:

'Class module
Sub Class_Globals
Public ABMComp As ABMCustomComponent
Dim myInternalName 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, radioName As String)
myInternalName = radioName
Dim CSS As String = $"
#half-stars-example .rating-group {
display: inline-flex;
}
#half-stars-example .rating__icon {
pointer-events: none;
}
/* This is an important part: we MUST override the Materialize CSS implementation of the the radio button! */
#half-stars-example .rating__input + label:before,
#half-stars-example .rating__input + label:after {
position: absolute !important;
left: -9999px !important;
}
#half-stars-example .rating__label {
cursor: pointer;
padding: 0 0.1em;
font-size: 2rem;
margin-top: 1rem;
}
#half-stars-example .rating__label--half {
padding-right: 0;
margin-right: -0.6em;
z-index: 2;
}
#half-stars-example .rating__icon--star {
color: orange;
}
#half-stars-example .rating__icon--none {
color: #eee;
}
#half-stars-example .rating__input--none:checked + .rating__label .rating__icon--none {
color: red;
}
#half-stars-example .rating__input:checked ~ .rating__label .rating__icon--star {
color: #ddd;
}
#half-stars-example .rating-group:hover .rating__label .rating__icon--star,
#half-stars-example .rating-group:hover .rating__label--half .rating__icon--star {
color: orange;
}
#half-stars-example .rating__input:hover ~ .rating__label .rating__icon--star,
#half-stars-example .rating__input:hover ~ .rating__label--half .rating__icon--star {
color: #ddd;
}
#half-stars-example .rating-group:hover .rating__input--none:not(:hover) + .rating__label .rating__icon--none {
color: #eee;
}
#half-stars-example .rating__input--none:hover + .rating__label .rating__icon--none {
color: red;
}"$
ABMComp.Initialize("ABMComp", Me, InternalPage, ID, CSS)
End Sub

Sub ABMComp_Build(InternalPage As ABMPage, internalID As String) As String
Return $"
<div id="half-stars-example">
<div id="${internalID}" class="rating-group"><input id="rating-0" class="rating__input rating__input--none" checked="checked" name="${myInternalName}" type="radio" value="0" />
<label class="rating__label" title="0 stars" for="rating-0"> </label>
<input id="rating-00" class="rating__input" type="radio" value="-1" />
<label class="rating__label rating__label--half" title="0.5 stars" for="rating-05"><i class="rating__icon rating__icon--star fa fa-star-half"></i></label>
<input id="rating-05" class="rating__input" name="${myInternalName}" type="radio" value="0.5" />
<label class="rating__label" title="1 star" for="rating-10"><i class="rating__icon rating__icon--star fa fa-star"></i></label>
<input id="rating-10" class="rating__input" name="${myInternalName}" type="radio" value="1" />
<label class="rating__label rating__label--half" title="1.5 stars" for="rating-15"><i class="rating__icon rating__icon--star fa fa-star-half"></i></label>
<input id="rating-15" class="rating__input" name="${myInternalName}" type="radio" value="1.5" />
<label class="rating__label" title="2 stars" for="rating-20"><i class="rating__icon rating__icon--star fa fa-star"></i></label>
<input id="rating-20" class="rating__input" name="${myInternalName}" type="radio" value="2" />
<label class="rating__label rating__label--half" title="2.5 stars" for="rating-25"><i class="rating__icon rating__icon--star fa fa-star-half"></i></label>
<input id="rating-25" class="rating__input" name="${myInternalName}" type="radio" value="2.5" />
<label class="rating__label" title="3 stars" for="rating-30"><i class="rating__icon rating__icon--star fa fa-star"></i></label>
<input id="rating-30" class="rating__input" name="${myInternalName}" type="radio" value="3" />
<label class="rating__label rating__label--half" title="3.5 stars" for="rating-35"><i class="rating__icon rating__icon--star fa fa-star-half"></i></label>
<input id="rating-35" class="rating__input" name="${myInternalName}" type="radio" value="3.5" />
<label class="rating__label" title="4 stars" for="rating-40"><i class="rating__icon rating__icon--star fa fa-star"></i></label>
<input id="rating-40" class="rating__input" name="${myInternalName}" type="radio" value="4" />
<label class="rating__label rating__label--half" title="4.5 stars" for="rating-45"><i class="rating__icon rating__icon--star fa fa-star-half"></i></label>
<input id="rating-45" class="rating__input" name="${myInternalName}" type="radio" value="4.5" />
<label class="rating__label" title="5 stars" for="rating-50"><i class="rating__icon rating__icon--star fa fa-star"></i></label>
<input id="rating-50" class="rating__input" name="${myInternalName}" type="radio" value="5" /></div>
</div>
"$
End Sub

public Sub GetCurrentRating(InternalPage As ABMPage) As Double
Dim script As String = $"return $('input[name=${myInternalName}]:checked').val();"$
Dim ret As Future = InternalPage.ws.EvalWithResult(script, Null)
InternalPage.ws.Flush

Return ret.Value
End Sub

public Sub SetCurrentRating(InternalPage As ABMPage, value As Double) {
Dim script As String = $" $('input[name=${myInternalName}][value="${value}"]').prop('checked', 'checked');"$
InternalPage.ws.Eval(script, Null)
InternalPage.ws.Flush
End Sub

' Is useful to run some initalisation script.
Sub ABMComp_FirstRun(InternalPage As ABMPage, internalID As String)
Dim script As String = $""$
InternalPage.ws.Eval(script, Array As Object(ABMComp.ID))
' flush not needed, it's done in the refresh method in the lib
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

ABMaterial users will notice I have added the CSS directly into the component. By doing so, we do not need to use the page.AddExtraCSSFile method in the Page_Build() method. (you can still do it this way, and in some cases it may be better as this part can be big. And in the final version, compress it!). In ABMaterial before version 3.75, using AddExtraCSSFile is the only way possible.

The only difficult part in the CSS was I had to override Materialize CSS’s implementation of a radio button (the ‘circle’). So we had to get rid of it.

2. Now we can make a variable for our StarComponent in the page Class_Globals, as we want to be able to Set and Get the value:

Dim myRating As CompStarRating

3. In Page_Connect() we add our component and a couple of buttons:

...
myRating.Initialize(page, "myRating", "rating")
page.Cell(1,1).AddComponent(myRating.ABMComp)

Dim btn As ABMButton
btn.InitializeFlat(page, "btn", "", "", "Get value", "")
page.Cell(2,1).AddComponent(btn)

Dim btn2 As ABMButton
btn2.InitializeFlat(page, "btn2", "", "", "Set 2.5 stars value", "")
page.Cell(3,1).AddComponent(btn2)
...
page.Refresh
...

4. And our Get and Set code in the buttons:

Sub btn_Clicked(Target As String)
Dim value As Double = myRating.GetCurrentRating(page)
Log(value)
End Sub

Sub btn2_Clicked(Target As String)
myRating.SetCurrentRating(page, 2.5)
End Sub

That is all! :)

Changes for versions of ABMaterial before 3.75

1. Save the CSS string into a text file (e.g. star.rating.css) and copy it to the /css/custom folder.
2. Remove the CSS param from ABMComp.Initialize(“ABMComp”, Me, InternalPage, ID, CSS)

ABMComp.Initialize("ABMComp", Me, InternalPage, ID) '<-- CSS param deleted

3. In Sub ABMComp_Build(InternalPage As ABMPage, internalID As String) As String remove the InteranlPage param:

Sub ABMComp_Build(internalID As String) As String

4. In Page_Build(), load the css file you created:

page.AddExtraCSSFile("custom/star.rating.css")

Alwaysbusy

Click here to Donation and support ABMaterial

Or make a donation with Bitcoins:

BTC: 13x7b12GonCj6iphnjLuonrwURK2jCgMdE

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13x7b12GonCj6iphnjLuonrwURK2jCgMdE

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B4XHelp: An ABMaterial WebApp for B4X Library documentation

b4xhelpI’ve created an ABMaterial (3.75) WebApp to show the documentation for the B4X libraries. Everyone who created a library for B4A, B4i or B4J can upload their .xml file to the WebApp and everyone can consult it. You can re-upload a new version for a library if needed.

Link: http://81.165.232.188:50912/b4xhelp/

HTTP/2 SSL Link: https://81.165.232.188:50911/b4xhelp/

b4xhelp

Notes:

  • This WebApp is open for everyone, but please try to keep it clean. Thank you!
  • B4XHelp is running on my personal Raspberry Pi with not a super-duper internet connection, so it also may give some indication how it handles a lot of users.
  • The libraries itself are NOT uploaded to the WebApp! Only the .xml files to parse them.
  • The WebApp also runs on a HTTP/2 server, but I do not have a verified certificate. If you use this link, you will get a warning that it may not be safe. You normally only need to accept this once:

priv

ABMaterial may be overwhelming at first with all its features at your disposal, but once you get the hang of it, creating such a WebApp as this, in pure B4J, can go very fast.

Alwaysbusy

Click here to Donation and support ABMaterial

Or make a donation with Bitcoins:

BTC: 13x7b12GonCj6iphnjLuonrwURK2jCgMdE

This is my bitcoin address as a QR code. It is possible to send bitcoins to me from mobile wallets by scanning this code.

13x7b12GonCj6iphnjLuonrwURK2jCgMdE

 

 


B4J: creating a reCAPTCHA component in ABMaterial

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 Donation and support ABMaterial

Or make a donation with Bitcoins:

BTC: 13x7b12GonCj6iphnjLuonrwURK2jCgMdE

This is my bitcoin address as a QR code. It is possible to send bitcoins to me from mobile wallets by scanning this code.

13x7b12GonCj6iphnjLuonrwURK2jCgMdE


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