Modifying SUSI Skills using SUSI Skill CMS

SUSI Skill CMS is a complete solution right from creating a skill to modifying the skill. The skills in SUSI are well synced with the remote repository and can be completely modified using the Edit Skill feature of SUSI Skill CMS. Here’s how to Modify a Skill.

  1. Sign Up/Login to the website using your credentials in skills.susi.ai
  2. Choose the SKill which you want to edit and click on the pencil icon.
  3. The following screen allows editing the skill. One can change the Group, Language, Skill Name, Image and the content as well.
  4. After making the changes the commit message can be added to Save the changes.

To achieve the above steps we require the following API Endpoints of the SUSI Server.

  1. http://api.susi.ai/cms/getSkillMetadata.json – This gives us the meta data which populates the various Skill Content, Image, Author etc.
  2. http://api.susi.ai/cms/getAllLanguages.json – This gives us all the languages of a Skill Group.
  3. http://api.susi.ai/cms/getGroups.json – This gives us all the list of Skill Groups whether Knowledge, Entertainment, Smalltalk etc.

Now since we have all the APIs in place we make the following AJAX calls to update the Skill Process.

  1. Since we are detecting changes in all the fields (Group Value, Skill Name, Language Value, Image Value, Commit Message, Content changes and the format of the content), the AJAX call can only be sent when there is a change in the PR and there is no null or undefined value in them. For that, we make various form validations. They are as follows.
    1. We first detect whether the User is in a logged in state.
if (!cookies.get('loggedIn')) {
            notification.open({
                message: 'Not logged In',
                description: 'Please login and then try to create/edit a skill',
                icon: <Icon type="close-circle" style={{ color: '#f44336' }} />,
            });
        }
  1. We check whether the image uploaded matches the format of the Skill image to be stored which is ::image images/imageName.png
if (!new RegExp(/images\/\w+\.\w+/g).test(this.state.imageUrl)) {
            notification.open({
                message: 'Error Processing your Request',
                description: 'image must be in format of images/imageName.jpg',
                icon: <Icon type="close-circle" style={{ color: '#f44336' }} />,
            });
        }
  1. We check if the commit message is not null and notify the user if he forgot to add a message.
if (this.state.commitMessage === null) {
            notification.open({
                message: 'Please make some changes to save the Skill',
                icon: <Icon type="close-circle" style={{ color: '#f44336' }} />,
            });
        }
  1. We also check whether the old values of the skill are completely similar to the new ones, in this case, we do not send the request.
if (toldValues===newValues {
            notification.open({
                message: 'Please make some changes to save the Skill',
                icon: <Icon type="close-circle" style={{ color: '#f44336' }} />,
            });
        }

To check out the complete code, go to this link.

  1. Next, if the above validations are successful, we send a POST request to the server and show the notification to the user accordingly, whether the changes to the Skill Data have been updated or not. Here’s the AJAX call snippet.
// create a form object
let form = new FormData();       
/* Append the following fields from the Skill Component:- OldModel, OldLanguage, OldSkill, NewModel, NewGroup, NewLanguage, NewSkill, changelog, content, imageChanged, old_image_name, new_image_name, image_name_changed, access_token */  
if (image_name_changed) {
            file = this.state.file;
            // append file to image
        }

        let settings = {
            "async": true,
            "crossDomain": true,
            "url": "http://api.susi.ai/cms/modifySkill.json",
            "method": "POST",
            "processData": false,
            "contentType": false,
            "mimeType": "multipart/form-data",
            "data": form
        };
        $.ajax(settings)..done(function (response) {
         //show success
        }.
        .fail(function(response){
         // show failure
        }
  1. To verify all this we head to the commits section of the SUSI Skill Data repo and see the changes we made. The changes can be seen here https://github.com/fossasia/susi_skill_data/commits/master 

Resources

  1. AJAX POST Request – https://api.jquery.com/jquery.post/ 
  2. Material UI – http://material-ui.com 
  3. Notifications – http://www.material-ui.com/#/components/notification 
Continue ReadingModifying SUSI Skills using SUSI Skill CMS

Implementing Search Functionality In Calendar Mode On Schedule Page In Open Event Webapp

f79b5a2b-b679-4095-8311-cf403193e0cc.png

Calendar Mode

fef75c16-da0a-4145-a2e5-620d63637194.png

The list mode of the page already supported the search feature. We needed to implement it in the calendar mode. The corresponding issue for this feature is here. The whole work can be seen here.

First, we see the basic structure of the page in the calendar mode.

<div class="{{slug}} calendar">
 <!-- slug represents the currently selected date -->
 <!-- This div contains all the sessions scheduled on the selected date -->
 <div class="rooms">
   <!-- This div contains all the rooms of an event -->
   <!-- Each particular room has a set of sessions associated with it on that particular date -->
   <div class="room">
     <!-- This div contains the list of session happening in a particular room -->
     <div class="session"> <!-- This div contains all the information about a session -->
       <div class="session-name"> {{title}} </div> <!-- Title of the session -->
       <h4 class="text"> {{{description}}} </h4> <!-- Description of the session -->
       <!-- This div contains the info of the speakers presenting the session -->
       <div class="session-speakers-list">
         <div class="speaker-name"><strong>{{{title}}}</div> <!-- Name of the speaker -->
           <div class="session-speakers-more"> {{position}} {{organisation}} </div> <!-- Position and organization of speaker-->
         </div>
       </div>
     </div>
   </div>
 </div>
</div>

The user will type the query in the search bar near the top of the page. The search bar has the class fossasia-filter.

c30a84c8-c456-4116-86fa-c5ffc382bdb3.png

We set up a keyup event listener on that element so that whenever the user will press and release a key, we will invoke the event handler function which will display only those elements which match the current query entered in the search bar. This way, we are able to change the results of the search dynamically on user input. Whenever a single key is pressed and lifted off, the event is fired which invokes the handler and the session elements are filtered accordingly.

Now the important part is how we actually display and hide the session elements. We actually compare few session attributes to the text entered in the search box. The text attributes that we look for are the title of the session, the name, position , and organization of the speaker(s) presenting the session. We check whether the text entered by the user in the search bar appears contiguously in any of the above-mentioned attributes or not. If it appears, then the session element is shown. Otherwise, its display is set to hidden. The checking is case insensitive. We also count the number of the visible sessions on the page and if it is equal to zero, display a message saying that no results were found.

For example:- Suppose the user enters the string ‘wel’ in the search bar, then we will iterate over all the different sessions and only those who have ‘wel’ in their title or in the name/ position/organization of the speakers will be visible. Rest all the sessions would be hidden.

Here is the excerpt from the code. The whole file can be seen here

$('.fossasia-filter').change(function() {
 var filterVal = $(this).val(); // Search query entered by user
 $('.session').each(function() { // Iterating through all the sessions. Check for the title of the session and the name of the
   // speaker and its position and organization
if ($(this).find('.session-name').text().toUpperCase().indexOf(filterVal.toUpperCase()) >= 0 ||
 $(this).find('.session-speakers-list a p span').text().toUpperCase().indexOf(filterVal.toUpperCase()) >= 0 || $(this).find('.speaker-name').text().toUpperCase().indexOf(filterVal.toUpperCase()) >= 0) {
     $(this).show(); // Matched so display the session
   } else {
     $(this).hide(); // Hide the Element
   }
 });
 var calFilterLength = $('.calendar:visible').length;
 if((isCalendarView && calFilterLength == 0)) { // No session elements found
   $('.search-filter:first').after('<p id="no-results">No matching results found.</p>');
 }
}).keyup(function() {
 $(this).change();
});

Below is the default view of the calendar mode on the schedule page

471d6b30-d8db-4dea-8593-df0ad68072a6.png

On entering ‘wel’ in the search bar, sessions get filtered

d6eec31e-fde1-4640-881b-a0216b68533d.png

 References:

Continue ReadingImplementing Search Functionality In Calendar Mode On Schedule Page In Open Event Webapp

API to List All Users on SUSI.AI

In this blog, I discuss how the SUSI server helps in listing out all the users registered on it. The only role Susi server plays is, Whenever it receives a request at

http://api.susi.ai/aaa/getUsers.json

The server evaluate the parameters in the request, validates them and notify the user accordingly. API needs 2 parameters, out of which access-token is a necessary. 2nd parameter has to be one from the given list :

Parameter Data type

  • getPageCount boolean
  • GetUserCount boolean
  • Page integer

On the basis of this 2nd parameter, server gets to know what does the client with given access-token is requesting. Server evaluates the access-token and validates that if the access token belongs to a user with user role atleast ADMIN, then the request is valid and proceed further with fetching the data in next step. Otherwise, server responds with error code “401” and error message “Base user role not sufficient”. It is advisable for clients that before redirecting users to admin panel or any other service, Please hit

http://api.susi.ai/aaa/showAdminService.json

And check that whether the user logged in is allowed to access the admin panel or not. The servlet /showAdminService.json is quite easy to understand for even those new to programming.

Coming back to our topic, by now, server knows that this client is authorized to access the user list. But what all information does server needs to provide? In response to this request, server encodes following attributes in the JSON Array {which is part of JSON object} and sends it to user :

Attribute Description

  • Name Email-Id of the user
  • Anonymous Is this user anonymous or not
  • User Role User Role of the user
  • Confirmed User has verified account or not
  • Last Login IP Last IP from which login was requested
  • Last Login Time Time when last login request was made
  • Signup Time When did the user signed up

First things first, check if enough parameters are provided or not. If not, respond with error stating “Bad Request. No parameter present”. Otherwise, server does a general iteration which has to be done irrespective of the 2nd parameter.

First of all, get a list of all the authorized users using getAuthorizedClients method of Data Access Object class. This method picks up all the keys from authorized file {which are nothing but identification of clients from which requests are received}. Though it, skips those key which are host addresses (which can not be used to identify a user), it does includes all the email ids {which are obvious identification of users}.

public static Collection<ClientIdentity> getAuthorizedClients() {
		ArrayList<ClientIdentity> i = new ArrayList<>();
		for (String id: authorization.keys()) {
		    if(id.contains("host"))
		        continue;
			i.add(new ClientIdentity(id));
		}
		return i;
	}

In next steps, the collection is converted to suitable data types over which iterations are easy and can be converted to JSON objects and Arrays easily. After this, server evaluates which parameter is requested in the request. Let us pick each case one by one for simplicity.

  1. Client has requested number of pages in the request.

Server finds the size of keysArray {one of the object containing list of all the users}. Basic Mathematics to find out how many pages would be formed if size of each page is 50 elements and total elements are given.

if (call.get("getPageCount", false) == true) {
            int pageCount = keysArray.length % 50 == 0 ? (keysArray.length / 50) : (keysArray.length / 50) + 1;
            result.put("pageCount", pageCount);
            result.put("accepted", true);
            result.put("message", "Success: Fetched count of pages");
            return new ServiceResponse(result);
        }
  1. User count is requested

Simply return sizeof list which has list of all the users. List to be used can be anyone from authorized, keysArray or any other derivative of authorized collection. Code is quite easy.

  1.      List of users on any page is requested.

Get the page number and after applying unitary maths, you will figure out the elementary of this.

for (Client client : authorized) {
                JSONObject json = client.toJSON();
                ClientIdentity identity = new ClientIdentity(ClientIdentity.Type.email, client.getName());
                Authorization authorization = DAO.getAuthorization(identity);
                UserRole userRole = authorization.getUserRole();
                json.put("userRole", userRole.toString().toLowerCase());
                userList.add(json);
            }

If any other attribute that is required, it’s encoding will be done here.  For example, to get user role of a user, generate a client identity followed by retrieval of user role from it. Encode it and send back to user.

Other details like last login IP, last login time and signup time are also fetched from respective files.

Resources

Continue ReadingAPI to List All Users on SUSI.AI

Change Password for SUSI Accounts Using Access Token and Email-ID

In this blog, I discuss how the SUSI server synchronizes with SUSI Accounts and SUSI webchat for users to Change Password. When a user logs in, the clients store the email id of the user along with the access token in cookies. These are stored once the client gets a positive login response from the server. Both of these are required at the time of making the final call. Web clients store the email id and access token in the following way.

cookies.set('loggedIn', loggedIn, { path: '/', maxAge: time });
cookies.set('emailId', email, { path: '/', maxAge: time });

First, the client has to ask the user to enter their current password. A javascript test is used to validate that at least 6 characters must be entered by the user. A similar test is run on the new password. But while confirming the password, client checks whether the user has entered the same password as new password or not. These are just the basics. In next stage (which is achieved only when all the above conditions are met), client encodes the email id (which it gets from cookies), current password, new password and the access token (which it again extracts from cookies).

Now, Client just has to make an ajax request to the server. The response is processed and sent back to the client. Let us now look at PasswordChange Servlet.

The base user role is defined as USER. Initial steps of the servlet are to extract the values form the request it receives. The values extracted from the request are in turn used to make a client’s identity. Before that, server checks if current and new password have same values or not. If not, then server returns a JSON response to user stating, “Your current password and new password matches”. Otherwise, it will continue its control flow as it is. Look at the code snippet below:

if(password.equals(newpassword)){
            result.put("message", "Your current password and new password matches");
            result.put("accepted", false);
            return new ServiceResponse(result);
        }

The reader here may think that they have discovered a hack. But they have not. Why? Because this is just the first step. In later stages, the hash of passwords are used to match to see whether the passwords match or not. To obtain a proper client identity, first a Client credentials object is made with support from the email id which is received in ‘changepassword’ attribute. Using the ClientCredentials object made above, an object of Authentication class is made. This object uses a method defined in its class to return a valid client identity. Using the client identity, value of password hash is extracted from the database along with the salt used to hash the password. If any error is encountered while extracting the client’s password hash value and/or salt value, an error is thrown towards the client, with a message stating “invalid credentials”.

ClientCredential pwcredential = new ClientCredential(ClientCredential.Type.passwd_login, useremail);
            Authentication authentication = DAO.getAuthentication(pwcredential);
            ClientCredential emailcred = new ClientCredential(ClientCredential.Type.passwd_login,
                authentication.getIdentity().getName());
            ClientIdentity identity = authentication.getIdentity();
            String passwordHash;
            String salt;

            try {
                passwordHash = authentication.getString("passwordHash");
                salt = authentication.getString("salt");
            } catch (Throwable e) {
                Log.getLog().info("Invalid password try for user: " + identity.getName() + " from host: " + post.getClientHost() + " : password or salt missing in database");
                result.put("message", "invalid credentials");
                throw new APIException(422, "Invalid credentials");
            }

Using the same salt value that was used earlier, a hash for password entered by the user will be generated which now matches  the previous value. This is the point where the hack you were thinking you found, failed. Again the server throws an error message if user’s credential did not match. Passwords are hard to handle and easy to guess. So here we have used quite many tests before changing them. Users are not allowed to use their email id as a password as well.

If the server is clear on all the above facts and tests, It finally generates a new hashed value of the password received in the parameter ‘newpassword’ and replaces the old hash value with the new one. To notify the clients that password change exited with a success response, it sends a JSON object with message “Your password has been changed!” and accepted flag set to true.

if (DAO.hasAuthentication(emailcred)) {
                    Authentication emailauth = DAO.getAuthentication(emailcred);
                    String newsalt = createRandomString(20);
                    emailauth.remove("passwordHash");
                    emailauth.put("passwordHash", getHash(newpassword, salt));
                    Log.getLog().info("password change for user: " + identity.getName() + " via newpassword from host: " + post.getClientHost());
                    result.put("message", "Your password has been changed!");
                    result.put("accepted", true);
                }

 

Additional Resources:

Wikipedia article: What is DAO?

Continue ReadingChange Password for SUSI Accounts Using Access Token and Email-ID

Creating A Better Responsive Design In Susper

A lot of work has been done on making Susper, a wonderful search-engine and still more work have to be done on it. To become a good competitor in the market, one should make their website UI design such that:

  • It should be eye-catching for the users on the first-time visit to the website.
  • It should be easy to use with simple UI features rather than having more complex UI features.

We have been more oriented towards the material design. We have used Bootstrap technology for designing UI. Earlier, we proposed an idea of creating a UI using Angular Material v2 but it was dropped due to time limitations and other issue priorities.

To make Susper a better competitor in the market, we made sure it should be responsive as well on the following devices:

  • Mobile screen devices:
    • 320px – Smaller screen size.
    • 375px – Medium screen size.
    • 425px – Larger screen size.
  • Tablets:
    • 768px – default screen size for tablets.
  • Laptops:
    • 1024px – Smaller screen size.
    • 1440px – Larger screen size.
  • 4K:
    • 2560px – Default screen size.

We targeted these devices using @media queries in CSS3. For e.g. if I want to make a site responsive for the mobile devices, I will be using:

@media screen and (minwidth: 320px) and (maxwidth: 425px) {
  // do something
}

 

Here, min-width: 320px means that the screen size should be greater than and equal to 320px and max-width: 425px means that the screen size should be less than and equal to 425px.

It is not necessary to use only these dimensions. Suppose if there is break in UI design between 320px and 425px then, one can add that screen size using @media query. In this case, nested @media queries play a quite good role.

@media screen and (minwidth: 320px) and (maxwidth: 425px) {
  // do something
  // let’s say, break in UI design is observed at 375px
  // add nested @media query
  @media screen and (minwidth: 375px) {
    // do something
  }
}

 

We’re still improving our CSS code at present following this grid pattern. One can check UI code at Susper repository hosted on GitHub: https://github.com/fossasia/susper.com

We have also used a lot of breakpoints which are not nested. But it’s good practice to break points in nested form. This will be solved while improving our CSS code.

Here are some screenshots of the current responsiveness of Susper:

  • Mobile screen devices:
  • Tablet devices:

  • Laptops:
  • 4K display:

Resources:

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Handling Errors While Parsing the yaml File in Yaydoc

Yaydoc, our automatic documentation generator uses a yaml file to read a user’s configuration. The internal configuration parser basically converts the yaml file to a python dictionary. Then, it serializes the values of that dictionary using a custom serialization format. From there it associates those values with environment variables which are then passed to bash scripts for various tasks such as deployment, generation, etc.. Some of those environment variables are again passed to another python layer which interacts with sphinx where they are deserialized before use. This whole system works pretty well for our use cases.

Now let’s assume a user adds a yaml file where they have a malformed section in the file. For example, to specify a theme, one needs to add the following to the yaml file.

build:
  theme:
    name: sphinx_fossasia_theme

But our user has the following in their yaml file.

build:
  theme: sphinx_fossasia_theme

Now this will raise an error as we expect a dictionary as a value for the key ‘theme’ but we got a string. Now how do we handle such cases without ignoring the entire file as that would be too much of a penalty for such a small mistake? One approach would have been to wrap each call to connect with a bunch of try-catch but that would render the code unreadable as the initial motivation for implementing the connect method was to abstract the internal implementation so that other contributors who may not be well versed with python can also easily add config options without needing to learn a bunch of python constructs.

So, what we did was that, while merging the dictionary containing default options and the dictionary containing the user preferences, we check whether the default has the same data type as that of the incoming value. If they are, It’s deemed safe to merge. There are certain relaxations though, like if the current type is a list, then the incoming value can be of any time as that can always be converted to a list of a single element. This is required to support the following syntax.

key:
  - value
key: value

The above two blocks are equivalent due to the above-mentioned approach although the type is different.

Now, after this pre-validation step is over we can ensure that the if the assumed type for a key is let’s say a dictionary, then it would be a dictionary. Hence no type errors would be raised like trying to access a dict method for another object, say a string which happened with the earlier implementation. After this, an extra parameter was added to the connect method to which we can now pass a validation function which if returns false, those values would be ignored. Usage of this feature has been implemented to a small level where we validate the links to subprojects and if they look like a valid github repo only then will they be included. Note that their existence is not checked. Only a regex based validation is performed.

It was also important to notify the user about these events when we detect that a specific section is invalid and provide informative and helpful error messages without failing the build. Hence proper error messages were also added which were informative so that the user knows exactly which section is to blame. This is similar to compilers where the error message is crucial to debug a certain piece of code.

Resources

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Uploaded Images History in Phimpme Android

In Phimpme Android one core feature is of sharing images to many different platforms. After sharing we usually wants to look in the our past records, where we uploaded what pictures? Which image we uploaded? What time it was? So I added a feature to view the upload history of images. User can go to the Upload history tab, present in the navigation drawer of the app. From there he can browse the repository.

How I added history feature in Phimpme

  • Store the data when User initiate an upload

To get which data uploading is in progress. I am storing its name, date, time and image path. When user approve to upload image from Sharing Activity.

Created a database model

public class UploadHistoryRealmModel extends RealmObject{

   String name;
   String pathname;
   String datetime;

   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   public String getPathname() {
       return pathname;
   }

   public void setPathname(String pathname) {
       this.pathname = pathname;
   }

   public String getDatetime() {
       return datetime;
   }

   public void setDatetime(String datetime) {
       this.datetime = datetime;
   }
} 

This is the realm model for storing the name, date, time and image path.

Saving in database

UploadHistoryRealmModel uploadHistory;
uploadHistory = realm.createObject(UploadHistoryRealmModel.class);
uploadHistory.setName(sharableAccountsList.get(position).toString());
uploadHistory.setPathname(saveFilePath);
uploadHistory.setDatetime(new SimpleDateFormat("dd/MM/yyyy HH:mm:ss").format(new Date()));
realm.commitTransaction();

Creating realm object and setting the details in begin and commit Transaction block

  • Added upload history entry in Navigation Drawer

    <LinearLayout
       xmlns:android="http://schemas.android.com/apk/res/android"
       android:id="@+id/ll_drawer_uploadhistory"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:background="@drawable/ripple"
       android:clickable="true"
       android:orientation="horizontal">
    
       <com.mikepenz.iconics.view.IconicsImageView
           android:id="@+id/Drawer_Upload_Icon"
           android:layout_width="@dimen/icon_width_height"
           android:layout_height="@dimen/icon_width_height"
           app:iiv_icon="gmd-file-upload"/>
    
       <TextView
           android:id="@+id/Drawer_Upload_Item"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="@string/upload_history"
           android:textColor="@color/md_dark_background"
           android:textSize="16sp"/>
    </LinearLayout>

It consist of an ImageView and TextView in a horizontal oriented Linear Layout

  • Showing history in Upload History Activity

Added recyclerview in layout.

<android.support.v7.widget.RecyclerView
   android:id="@+id/upload_history_recycler_view"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:layout_below="@id/toolbar">
</android.support.v7.widget.RecyclerView>

Query the database and updated the adapter of Upload History

uploadResults = realm.where(UploadHistoryRealmModel.class);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
uploadHistoryRecyclerView.setLayoutManager(layoutManager);
uploadHistoryRecyclerView.setAdapter(uploadHistoryAdapter);

Added the adapter for recycler view and created an Item using Constraint layout.

Resources

Continue ReadingUploaded Images History in Phimpme Android

Using RecyclerView Instead Of ViewPager For Gallery

Phimpme is an Image app that provide camera, editing ,sharing options and a gallery section. The Gallery section allows us to view large number of images that are locally available in the users device. Generally developers used viewpager to swipe the horizontal images although we are also using viewPager but the problem is it is taking more time to load large size images and that disturb the user smooth experience. After so much research I came to new solution. So in this post, I will be explaining how to use recyclerview to view gallery images instead of viewPager.

Let’s get started

Make sure you have Recyclerview support in your dependencies in build.gradle. As recyclerView required an adapter and viewHolder to set data in recyclerView. So I will be explaining about adapter.

ViewHolder for RecyclerView

public static class ViewHolder extends RecyclerView.ViewHolder {
  ImageView imageView;
  LinearLayout linearLayout;

  public ViewHolder(View itemView) {
      super(itemView);
      imageView = new ImageView(context);
      linearLayout = (LinearLayout) itemView.findViewById(R.id.layout);
      WindowManager wm = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);
      Display display = wm.getDefaultDisplay();
      Point size = new Point();
      display.getSize(size);
      int width = size.x;
      int height = size.y;
      LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
              width, height);
      imageView.setLayoutParams(params);
      imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
      linearLayout.addView(imageView);
  }
}

Right now the imageView is adjusting according to device screen size so that it will be compatible with all devices.

I am passing the width and height in LayoutParams to parent of imageview i.e in our case linearlayout is parentView.

Adapter for RecyclerView

public ImageAdapter(ArrayList<Media> media) {
  this.media = media;
}

@Override
public ImageAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
  View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.unit_image_pager, null, false);

  return new ViewHolder(view);
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
  Glide.with(getContext())
          .load(media.get(position).getUri())
          .diskCacheStrategy(DiskCacheStrategy.SOURCE)
          .thumbnail(0.5f)
          .into(holder.imageView);
  holder.imageView.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
          basicCallBack.callBack(0,null);
      }
  });
}

MediaList is an arrray of media that contains the list of images with URI that will help to load images. I am using Glide to load images you can use any library to load images. Adapter helps to load data in recyclerView.

Now set viewPager where you require to scroll images horizontally

@Nullable @BindView(R.id.photos_pager)
RecyclerView mRecylerPager;
mRecylerPager.setLayoutManager(linearLayoutManager);
mRecylerPager.setHasFixedSize(true);
mRecylerPager.setLongClickable(true);

Our recycler view is ready now the most important part is to set things onPageChangeListner. For example : In Phimpme we are getting path of current position image to show in image description so to update the value we are writing that codde in onPageChangeListner and to update the toolbar.

mViewPager.setOnPageChangeListener(new PagerRecyclerView.OnPageChangeListener() {
  @Override
  public void onPageChanged(int oldPosition, int position) {
      getAlbum().setCurrentPhotoIndex(position);
      toolbar.setTitle((position + 1) + " " + getString(R.string.of) + " " + size_all);
      invalidateOptionsMenu();
      pathForDescription = getAlbum().getMedia().get(position).getPath();
  }
});

To scroll to the given position we require to set the position to recyclerView and it can be done by the following code

mViewPager.scrollToPosition(getCurrentPsotion());

This is how I implemented the recyclerView instead of ViewPager to load gallery images faster as compare to ViewPager.

RecyclerView in Phimpme to load gallery Images

Resources:     

 

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