The HTML Kit makes it easy to build web pages that interact with DevLess, without writing a line of JavaScript.
To get started with editing data for a table, you can use automatically generated "Scaffolds" for a table. Go to the list of tables in your application, and press the button looking like this: </>. This will download a html file to your browser's download folder.
You can open this file in a browser, and you will be able to interact with the DevLess data directly. Try editing it! This file is meant to be a starting point for writing web applications using DevLess.
This document aims to describe how one can interact with DevLess with quite simple, but detailed, examples. For a larger example of how DevLess can be used, check out the starter pack. There is also a video tutorial on the starter pack setup here.
Go to your DevLess instance, press this buttton: 
. It is located at the top right in your DevLess panel. It should present you with an HTML tag to connect to your instance. It should look something like this:
<script src="http://bestapp.herokuapp.com/js/devless-sdk.js" class="devless-connection" devless-con-token="abcde123456789"></script>Copy the tag from your instance into a HTML page, and you are connected!
In order to add data to a service, you can use a form tag with a class of dv-add-oneto:SERVICE:TABLE.
For example, say that I have a service named contacts with a table named people. I can then use a form with a class of dv-add-oneto:contacts:people. Any inputs within this form will be mapped to the columns in the people table based on the name property.
For example, using the following markup we can add people with name & email to the people table:
<div class="dv-notify-success" style="color: green">Person added</div>
<div class="dv-notify-failed" style="color: red">Failed to add person</div>
<form class="dv-add-oneto:contacts:people">
<input type="text" name="name" placeholder="Name"><br>
<input type="text" name="email" placeholder="Email"><br>
<button type="submit">Submit</button>
</form>
The dv-notify-success and dv-notify-failed classes is a means of getting notifications about if the operation succeeded or not. The dv-notify-success element will be hidden until a person was successfully added, while dv-notify-failed will be hidden until something goes wrong. For example, connection failures or incorrect input.
In order to list data, you can use the dv-get-all:SERVICE:TABLE class. This makes the HTML SDK repeat the inner HTML for all entries in the table. You can use the var-NAME class to populate that element with that entry's value for the column referred to by the NAME.
The classes can be used on any kind of html tag. This makes it trivial to layout your webpage any way you want it.
The var-NAME syntax can also be used within the href attribute of the <a> tag. Note that the <a> tag also needs to have class="var-NAME" set. Within the href attribute, the var-NAME part is interpolated, i.e. you can surround it with other text.
Accessing data in referred tables can be done by using var-REFERED_TABLE_NAME. E.g. var-category-name for a product, which is linked to a category table with a field name.
For example, we can create a list of all our contacts like this:
<div class="dv-notify"></div>
<ul class="dv-get-all:contacts:people">
<li>
<span class="var-name"></span>:
<a class="var-email" href="mailto:var-email">
<span class="var-email"></span>
</a>
</li>
</ul>
NB: In the case of image tags remember to set an empty src tag <img src="" class="var-image"/>
Here we list all entries in the people table in the contacts service. For each contact we print their name and their email. For the email, we also add a mailto link.
NB: In the case of image tags remember to set an empty src tag <img src="" class="var-image"/>
The classes can be used on any kind of html tag. This makes it trivial to layout your webpage any way you want it.
Data can be selected based on any column. This is done by using the dv-where prefix to the get-all class. For example, if I wanted to select all contacts with the name of 'joe', we would do it like this:
<div class="dv-notify"></div>
<ul class="dv-where:name:joe-get-all:contacts:people">
<li>
<span class="var-name"></span>:
<a class="var-email" href="mailto:var-email">
<span class="var-email"></span>
</a>
</li>
</ul>
You can use any of the fields in the row to do this, just replace the name and joe part with the column name and the value.
If you only want to show one entry, use this technique but with a unique key in the where-clause.
Using our previous data listing as the base, we can add deletion functionality by using the dv-delete class. The dv-delete class can be used within a listing, on <a> or <button> elements.
<div class="dv-notify"></div>
<ul class="dv-get-all:contacts:people">
<li>
<span class="var-name"></span>:
<a class="var-email" href="mailto:var-email">
<span class="var-email"></span>
</a>
<button class="dv-delete">Delete</button>
</li>
</ul>
When it comes to updating existing data, we use a combination of the dv-update and dv-update-oneof classes. Within a listing, use the dv-update class on a <button> or <a> tag. Then, create a <form> with the fields you want to update with a class of dv-update-oneof:SERVICE:TABLE. As when adding data, the name of the input elements map to columns in the table.
For example, to updating emails in our contact book:
<div class="dv-notify"></div>
<ul class="dv-update-oneof:contacts:people">
<li>
<span class="var-name"></span>:
<a class="var-email" href="mailto:var-email">
<span class="var-email"></span>
</a>
<button class="dv-update">Update</button>
</li>
</ul>
<form class="dv-update-oneof:contacts:people">
<input type="text" name="email" placeholder="Update email">
<button type="submit">Update</button>
</form>
To signup a user , you will need to add the dv-signup class. You will need to place this in the form tag. Also the list of registered users can be found under the users tab on your DevLess instance.
NB: DevLess will move to the URL set for the action attribute on a successful signup.
The example code below illustrates signing up a user and moving to the dashboard page on success.
<div class="dv-notify"></div>
<form class="dv-signup" action="/dasboard">
<input type="text" name="username" placeholder="Enter username here">
<input type="email" name="email" placeholder="Enter email here">
<input type="number" name="phonenumber" placeholder="Enter phone number here">
<input type="text" name="firstname" placeholder="Enter first name here">
<input type="text" name="lastname" placeholder="Enter last name here">
<input type="password" name="password" placeholder="Enter password here">
<button type="submit">Signup</button>
</form>
To sign in users, you will need to add the dv-signin class to a form.
You will also need to pick either phonenumber , email or username as an identifier and a password for signin.
The example below uses username and password for sign in
<div class="dv-notify"></div>
<form class="dv-signin" action="/dasboard">
<input type="text" name="username" placeholder="Enter username here">
<!--<input type="email" name="email" placeholder="Enter email here">-->
<!--<input type="number" name="phonenumber" placeholder="Enter phone number here">-->
<!-- Choose between username, phone_number and email-->
<input type="password" name="password" placeholder="Enter password here">
<button type="submit">Signin</button>
</form>
Once you are either signed in or signed up. You can now display the profile of the user. You will need the dv-profile class and use var-<profile_field> to get the the field value.
<div class="dv-profile">
<span class="var-username"></span>
<span class="var-email"></span>
<span class="var-firstname"></span>
<span class="var-last_name"></span>
<span class="var-phone_number"></span>
</div>
You can update the profile of a signed up or signed in user using a form.
You will need to add the dv-updateProfile class to the form as well as the fields to be updated.
<div class="dv-notify"></div>
<form class="dv-updateProfile">
<input type="text" name="username">
<input type="email" name="email">
<input type="text" name="firstname">
<input type="text" name="lastname">
<input type="number" name="phone_number">
<input type="password" name="password">
<button type="submit">Update profile</button>
</form>
Logging out a user is as simple as adding the dv-logout class and an action attribute to redirect to once the user is logged out.
<button class="dv-logout" action="/">Logout</button>
There are situations where you might want to set a value of an attribute. EG: Setting the value of a select box.
<select class="dv-get-all:service_name:table_name">
<option class="set-value:var-id "></option>
</select>
The above code will generate a series of option tags each looking like <option value="1">Beverages</option> with changes depending on data from table_name.
To make you page more interactive you may use dv-notify as well as the dv-processing classes.
General notifications: For every of the above operations except for a successful query DevLess returns a more generic message . You may display this by adding the class <div class="dv-notify"></div> This will print out the message as sent from the DevLess backend. These kind of messages are good for debugging purposes.
Specialized notifications: Most likely you will like to show your users friendly message. In this case you may use <div class="dv-notify-success">your success message here :)</div> for successful operations and <div class="dv-notify-failed">you failure message goes here :(</div> for failed operations.
Progress notifications: Some operations might take a couple of seconds and might lead to users having to wait. Its best practice to signal the user when the task starts and when its done. You can use <div class="dv-processing">Sending...</div> to notify users when the processing begins and <div class="dv-doneProcessing">Done</div> when the operation is done