7
March
2022
Engineering

New Intelligent Drag and Drop Experience for Appsmith’s User Interface Builder

Developers can quickly build any custom business software with pre-built UI widgets that connect to any data source on Appsmith. It’s a reliable and fast method to develop internal tools quickly. We created Appsmith to help developers save valuable time building complex applications for internal uses within their organizations. For this to work for everyone, we believe that the core parts of Appsmith need to run smoothly and should be continuously improved.  Appsmith’s UI is built using React, Redux, Web Workers, Immer, among other things. 

One of the key issues that users faced with Appsmith was that when they would drag the widgets onto the canvas, they would only get dragged in if there was enough space on the drop area. This was not a pleasant experience; it would involve dragging the widget onto some other free area on the canvas, re-designing the desired drop area, and then dragging it up. We realized that this was a significant flaw slowing down the UI building process. So we immediately fixed it.  

Click here to view the issue


In this blog, we’ve interviewed Appsmith engineers Ashok M and Rahul Ramesha to learn more about the process and challenges involved in solving this problem. 

What was the issue with resizing and dragging widgets? 

Simply put, the problem that we had was that whenever we would drag a new widget or any existing widget into a position where it would collide with any other widget, that kind of movement was often restricted. We did not have an option to auto-resize the widget dragged into a particular space. There was also no possibility for the existing widgets on the page to automatically move around to make space for a new widget. For anyone trying to create an application, this can be a frustrating experience because when users design things, they don’t necessarily do it in order. There are many instances where they might remember to add something later. We wanted the experience of making an app on Appsmith should be smooth and delightful. 

Take a look at the screenshots below to see the previous experience:  


When you try to resize a widget, and there’s a widget already in the path, a user would not be able to resize the new widget without explicitly moving the existing widgets out of the way. 


In this image above, you can see that the ‘Container’ widget cannot be resized into the size shown in the image below without moving the ‘Checkbox’ widget.


These problems often arise when there is a real estate shortage on the canvas, when the widget's size falls short by a small size change or when the movement of other widgets is restricted within a particular space. For example, when placing a button between two existing buttons, the widget being dragged is one column size larger than the available space on the canvas. Generally speaking, users don't usually know how much resizing needs to be done to the existing widgets to make space for a new widget or dragging other previously dragged-in widgets.

What was user feedback around this issue? 

Users often asked us to allow dropping widgets on top of each other (which some of the UI building products and most of the canvas building products provide) to deal with UI block collision checks. These checks ensure that no two widgets are overlapping and are fully/partially out of the main canvas. Going in this direction would have meant building layers and dealing with layers. 

For some context, layers are actually Z-Index layers, which could have allowed for dropping widgets one on top of the other by adding a higher Z-index value. An example that comes to mind is Adobe Photoshop; Tooljet, Miro, Figma also allow layers in a way. For Appsmith, this kind of a solution isn’t ideal because one can often forget that there are widgets behind a widget in a lower Z-index layer, and adding more layers would mean more time for the dom to render and paint. 

After a few internal discussions around this, we found that this would not be a scalable solution, and it would also make resizing, selecting, focusing widgets very difficult. We also want to develop the experience of building UI on Appsmith to be more intelligent. 


Can you elaborate on this vision of enhancing UI building experience and the solution you created? 

When we brainstormed this issue, we knew that the solution had to be scalable. It also had to be intelligent enough to auto-adjust according to the screen resolutions of different devices. We wanted to develop Reflow as a solution to this problem. Reflow is a process of technically deciding which widgets to move and resize in real-time to allow space for the dragging/resizing widget. Widget resizing allows the user to resize a widget while holding another widget to make space. This only works when the widget is cramped against a boundary on the canvas.

How did you go about developing the solution? What were some other approaches you had considered, and what were their limitations? 

Conceptualizing and building this feature took less than time than expected. However, we spent time thinking about the right solution. We did this by trying out POCs of different solutions. We built three POCs to realize that reflowing while dragging would be an essential part of our solution. We then also had to consider the two behaviors of Reflow: Natural and Relative. 

Natural: 

  • While resizing a static widget, when colliding with a widget in a particular direction, the widgets reflow after cascading collision without maintaining any relative spacing
  • While dragging a static widget, the widgets reflow similar with cascading collisions. Even here, the dragging widget can be made to fit into any space.

Relative: 

  • While resizing a static widget, when colliding with a widget in a particular direction, all the widgets in the path of collision of the colliding widget will be moved while maintaining relative spacing till the edge of the canvas. At the edge of the canvas, it reduces the relative spacing on further resizing a static widget.
  • While dragging a static widget, when colliding with a widget in a particular direction, all the widgets move as per the reflow algorithm, similar to resizing reflow. The direction of collision is critical while reflowing with dragging. The static widget itself can move other widgets that can help fit in between any space on the canvas.

We developed two more POCs to get feedback on which reflow was more user-friendly and likable. We understood that ‘Natural’ was more predictable, but both behaviors had their own merits. Finally, we built “Drag and Drop Experience” to resize widgets at the corners to allow space for the dragging widget, which seemed essential. 


Can you explain your the new algorithm for the experience? 

At its core, the algorithm’s behavior is to push all the widgets the dragged widget is colliding with. Let us explain what happens under the hood in more detail; consider the widget dragged on the canvas to be a ‘static’ widget. When this type of widget is dragged onto the canvas, we compare its coordinates with all other widgets on the canvas to check for overlapping collisions. The overlapping widgets are further put through the same process recursively. This helps create a tree structure of widgets, wherein a parent node will have overlapping widgets as children nodes and become parents for their overlapping widgets. With the help of this tree structure, the direction of the static widget, displacement of the static widget and canvas boundaries, X and Y movement values of each widget are calculated. When moved along the X and Y axis from their original position, these widgets will create the illusion of pushing the colliding widgets.

Here’s a link to the code where this algorithm is implemented

This is the core logic of our algorithm, but there’s a lot more to this. For example, we are tweaking the direction of movement in corner cases, keeping track of multiple directions of widgets, smooth canvas exits, and entries, among a few more.


Can this algorithm be applied in other scenarios or projects?

So we will extend this project to the cut/copy/paste feature where you can paste a widget anywhere on the canvas, and the rest of the widgets will move away to make space for the copied widget. We will also be including it in the dynamic height project, where widgets like Table, List etc. can grow in height and push other widgets to the bottom. Another extension for this algorithm would be to push widgets around based on device resolutions, ie, develop position responsiveness of widgets.


Can you talk about the performance of your fix? What happens when there are hundreds of widgets on the canvas?

We tested it out with 100 widgets, and there was no problem with performance, but performance is expected to degrade with more and more widgets. We tested this out with our high-performance laptops by slowing down the CPU by 6x using Chrome’s CPUthrottle; there were minor lags but nothing that is unusable. 


What is the roadmap of this particular feature? Are there any further enhancements and improvements that you’re planning to make? 

We think that this is just the beginning! We’ve got some significant enhancements planned. 

  • Multiple widget reflow (Major Enhancement):

Reflow widgets even when multiple widgets are moved together.

  • Locked widgets (Major Enhancement):

So container jumps(moving a widget from the main canvas into a container or vice versa) will be tricky and irritate some users because people might not want to move widgets from the carefully designed positions. So we will lock a widget not to allow it to resize or move from its position.

  • Dynamic resize limit (Minor Enhancement): 

There is a resize limit for our widgets: 4 rows x 2 columns, and the same for all widgets. We can’t go below these dimensions. It doesn't make sense for widgets like a divider or sometimes button and checkbox, so we might try to get the minimum dimensions in real-time based on the widget it affects.

What was the most challenging part of building this feature? 

Building this feature was quite challenging because there aren’t many readily available examples on the internet; and building this also meant enabling others to understand what was in our minds. We wrote close to 8000 lines of code. Still, we’ve pushed only 4500 lines into the repo because we have had to build two behaviors to understand the solution among internal stakeholders better. 

We learned that there is no right way to build new experiences. Different solutions helped solve issues in different scenarios. We could always come up with a scenario that would cause the existing solution to fail. In the end, we had to choose a solution that catered to most of the scenarios and not all.

In the beginning, we built a solution to do one thing: to push colliding widgets in a direction and then add code to tackle one problem at a time. As the solution started to feel more and more refined, other problems surfaced. While trying to tackle a complex problem, identifying the core logic of the solution and adding to it one step at a time is critical in solving it.



Ashok M is a Frontend Engineer at Appsmith. 

Rahul Ramesha is a Frontend Engineer at Appsmith. 


We hope that you enjoyed reading this blog.

Appsmith is built in public, and we love sharing our knowledge with everyone. If you have a special request to know more about behind-the-scenes for specific features, write to me vishnupriya@appsmith.com


New Intelligent Drag and Drop Experience for Appsmith’s User Interface Builder

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Developers can quickly build any custom business software with pre-built UI widgets that connect to any data source on Appsmith. It’s a reliable and fast method to develop internal tools quickly. We created Appsmith to help developers save valuable time building complex applications for internal uses within their organizations. For this to work for everyone, we believe that the core parts of Appsmith need to run smoothly and should be continuously improved.  Appsmith’s UI is built using React, Redux, Web Workers, Immer, among other things. 

One of the key issues that users faced with Appsmith was that when they would drag the widgets onto the canvas, they would only get dragged in if there was enough space on the drop area. This was not a pleasant experience; it would involve dragging the widget onto some other free area on the canvas, re-designing the desired drop area, and then dragging it up. We realized that this was a significant flaw slowing down the UI building process. So we immediately fixed it.  

Click here to view the issue


In this blog, we’ve interviewed Appsmith engineers Ashok M and Rahul Ramesha to learn more about the process and challenges involved in solving this problem. 

What was the issue with resizing and dragging widgets? 

Simply put, the problem that we had was that whenever we would drag a new widget or any existing widget into a position where it would collide with any other widget, that kind of movement was often restricted. We did not have an option to auto-resize the widget dragged into a particular space. There was also no possibility for the existing widgets on the page to automatically move around to make space for a new widget. For anyone trying to create an application, this can be a frustrating experience because when users design things, they don’t necessarily do it in order. There are many instances where they might remember to add something later. We wanted the experience of making an app on Appsmith should be smooth and delightful. 

Take a look at the screenshots below to see the previous experience:  


When you try to resize a widget, and there’s a widget already in the path, a user would not be able to resize the new widget without explicitly moving the existing widgets out of the way. 


In this image above, you can see that the ‘Container’ widget cannot be resized into the size shown in the image below without moving the ‘Checkbox’ widget.


These problems often arise when there is a real estate shortage on the canvas, when the widget's size falls short by a small size change or when the movement of other widgets is restricted within a particular space. For example, when placing a button between two existing buttons, the widget being dragged is one column size larger than the available space on the canvas. Generally speaking, users don't usually know how much resizing needs to be done to the existing widgets to make space for a new widget or dragging other previously dragged-in widgets.

What was user feedback around this issue? 

Users often asked us to allow dropping widgets on top of each other (which some of the UI building products and most of the canvas building products provide) to deal with UI block collision checks. These checks ensure that no two widgets are overlapping and are fully/partially out of the main canvas. Going in this direction would have meant building layers and dealing with layers. 

For some context, layers are actually Z-Index layers, which could have allowed for dropping widgets one on top of the other by adding a higher Z-index value. An example that comes to mind is Adobe Photoshop; Tooljet, Miro, Figma also allow layers in a way. For Appsmith, this kind of a solution isn’t ideal because one can often forget that there are widgets behind a widget in a lower Z-index layer, and adding more layers would mean more time for the dom to render and paint. 

After a few internal discussions around this, we found that this would not be a scalable solution, and it would also make resizing, selecting, focusing widgets very difficult. We also want to develop the experience of building UI on Appsmith to be more intelligent. 


Can you elaborate on this vision of enhancing UI building experience and the solution you created? 

When we brainstormed this issue, we knew that the solution had to be scalable. It also had to be intelligent enough to auto-adjust according to the screen resolutions of different devices. We wanted to develop Reflow as a solution to this problem. Reflow is a process of technically deciding which widgets to move and resize in real-time to allow space for the dragging/resizing widget. Widget resizing allows the user to resize a widget while holding another widget to make space. This only works when the widget is cramped against a boundary on the canvas.

How did you go about developing the solution? What were some other approaches you had considered, and what were their limitations? 

Conceptualizing and building this feature took less than time than expected. However, we spent time thinking about the right solution. We did this by trying out POCs of different solutions. We built three POCs to realize that reflowing while dragging would be an essential part of our solution. We then also had to consider the two behaviors of Reflow: Natural and Relative. 

Natural: 

  • While resizing a static widget, when colliding with a widget in a particular direction, the widgets reflow after cascading collision without maintaining any relative spacing
  • While dragging a static widget, the widgets reflow similar with cascading collisions. Even here, the dragging widget can be made to fit into any space.

Relative: 

  • While resizing a static widget, when colliding with a widget in a particular direction, all the widgets in the path of collision of the colliding widget will be moved while maintaining relative spacing till the edge of the canvas. At the edge of the canvas, it reduces the relative spacing on further resizing a static widget.
  • While dragging a static widget, when colliding with a widget in a particular direction, all the widgets move as per the reflow algorithm, similar to resizing reflow. The direction of collision is critical while reflowing with dragging. The static widget itself can move other widgets that can help fit in between any space on the canvas.

We developed two more POCs to get feedback on which reflow was more user-friendly and likable. We understood that ‘Natural’ was more predictable, but both behaviors had their own merits. Finally, we built “Drag and Drop Experience” to resize widgets at the corners to allow space for the dragging widget, which seemed essential. 


Can you explain your the new algorithm for the experience? 

At its core, the algorithm’s behavior is to push all the widgets the dragged widget is colliding with. Let us explain what happens under the hood in more detail; consider the widget dragged on the canvas to be a ‘static’ widget. When this type of widget is dragged onto the canvas, we compare its coordinates with all other widgets on the canvas to check for overlapping collisions. The overlapping widgets are further put through the same process recursively. This helps create a tree structure of widgets, wherein a parent node will have overlapping widgets as children nodes and become parents for their overlapping widgets. With the help of this tree structure, the direction of the static widget, displacement of the static widget and canvas boundaries, X and Y movement values of each widget are calculated. When moved along the X and Y axis from their original position, these widgets will create the illusion of pushing the colliding widgets.

Here’s a link to the code where this algorithm is implemented

This is the core logic of our algorithm, but there’s a lot more to this. For example, we are tweaking the direction of movement in corner cases, keeping track of multiple directions of widgets, smooth canvas exits, and entries, among a few more.


Can this algorithm be applied in other scenarios or projects?

So we will extend this project to the cut/copy/paste feature where you can paste a widget anywhere on the canvas, and the rest of the widgets will move away to make space for the copied widget. We will also be including it in the dynamic height project, where widgets like Table, List etc. can grow in height and push other widgets to the bottom. Another extension for this algorithm would be to push widgets around based on device resolutions, ie, develop position responsiveness of widgets.


Can you talk about the performance of your fix? What happens when there are hundreds of widgets on the canvas?

We tested it out with 100 widgets, and there was no problem with performance, but performance is expected to degrade with more and more widgets. We tested this out with our high-performance laptops by slowing down the CPU by 6x using Chrome’s CPUthrottle; there were minor lags but nothing that is unusable. 


What is the roadmap of this particular feature? Are there any further enhancements and improvements that you’re planning to make? 

We think that this is just the beginning! We’ve got some significant enhancements planned. 

  • Multiple widget reflow (Major Enhancement):

Reflow widgets even when multiple widgets are moved together.

  • Locked widgets (Major Enhancement):

So container jumps(moving a widget from the main canvas into a container or vice versa) will be tricky and irritate some users because people might not want to move widgets from the carefully designed positions. So we will lock a widget not to allow it to resize or move from its position.

  • Dynamic resize limit (Minor Enhancement): 

There is a resize limit for our widgets: 4 rows x 2 columns, and the same for all widgets. We can’t go below these dimensions. It doesn't make sense for widgets like a divider or sometimes button and checkbox, so we might try to get the minimum dimensions in real-time based on the widget it affects.

What was the most challenging part of building this feature? 

Building this feature was quite challenging because there aren’t many readily available examples on the internet; and building this also meant enabling others to understand what was in our minds. We wrote close to 8000 lines of code. Still, we’ve pushed only 4500 lines into the repo because we have had to build two behaviors to understand the solution among internal stakeholders better. 

We learned that there is no right way to build new experiences. Different solutions helped solve issues in different scenarios. We could always come up with a scenario that would cause the existing solution to fail. In the end, we had to choose a solution that catered to most of the scenarios and not all.

In the beginning, we built a solution to do one thing: to push colliding widgets in a direction and then add code to tackle one problem at a time. As the solution started to feel more and more refined, other problems surfaced. While trying to tackle a complex problem, identifying the core logic of the solution and adding to it one step at a time is critical in solving it.



Ashok M is a Frontend Engineer at Appsmith. 

Rahul Ramesha is a Frontend Engineer at Appsmith. 


We hope that you enjoyed reading this blog.

Appsmith is built in public, and we love sharing our knowledge with everyone. If you have a special request to know more about behind-the-scenes for specific features, write to me vishnupriya@appsmith.com


What’s a Rich Text element?

The rich text element allows you to create and format headings, paragraphs, blockquotes, images, and video all in one place instead of having to add and format them individually. Just double-click and easily create content.

  • xvcmbmvkmnkmbknmbkmlnj
  • A rich text element can be used with static or dynamic content. For static content, just drop it

A rich text element can be used with static or dynamic content. For static content, just drop it into any page and begin editing. For dynamic content, add a rich text field to any collection and then connect a rich text element to that field in the settings panel. Voila!

  1. A rich text element can be used with static or dynamic content. For static content, just drop it into any page and begin editing. For dynamic content, add a rich text field to any collection and then connect a rich text element to that field in the settings panel. Voila!

How to customize formatting for each rich text

Headings, paragraphs, blockquotes, figures, images, and figure captions can all be styled after a class is added to the rich text element using the "When inside of" nested selector system.

ksnopirirfnb [aorewmb[oiewsn b[opebr
  1. then connect a rich text

dfbstjsrykmsry

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Debugging your apps in Appsmith with the Appsmith Debugger, part 2
27
September
2022
Product

Debugging your apps in Appsmith with the Appsmith Debugger, part 2

Debugging your apps in Appsmith with the Appsmith Debugger, part 2
Ayush Pahwa
0
 minutes ↗
#
product
#
errors
#
troubleshooting
#
debugger
Product
Meet the sidekicks, Logs and Inspect Entity

The first part of this teardown helped you see how the Error pane can save you hours in debugging and build better internal apps. In this one, let’s meet two seemingly innocuous features that can give you debugging super-powers when used right.

Logs

The Logs pane shows you everything logged by Appsmith and, like Errors, in lockstep with the sequence of code execution in your build. Borrowing from the experience of showing logs in general—in the browser console, from a shell, or on your favorite IDE—the Logs pane has four views for specific debugging use cases.

Post_5.jpg (1920×1080)

All Logs

This view shows you all logs timestamped by when we saw them in your Appsmith session. Updated a widget’s property? Wrote a new action to your GraphQL datasource? Ran a JS Object to concat two queries? It all gets logged, including the errors you see in the Errors pane, in a separate view called Error Logs. You will see how that can be useful in a GIF, pun intended.

The All Logs view can be a little overwhelming, though, and a bit of work when you have been at your build for a while. For easier tracking of relevant logs, use one of the three options below.

Post_6.gif (1440×810)

Errors Logs

Everything you learned about the Errors pane applies to this view, too, but there’s more to this view. Here's a likely scenario to show that.

State #1

You have a button to reload a table, presumably to refresh the data from your datasource.

Condition #1

You use the Button property, onClick, which runs the query to fetch the latest data into the table.

Scenario #1

Your query fails.

- On just the Error pane

  • You see just the error for the failing query. Although helpful, it doesn’t offer context for the before and after of the error.

- On the Error Logs pane under Logs

  1. You see logs for the Button click and the executed onClick event .
  2. Because the onClick property is binded to queries and JS Objects, you see the ones that are successfully executed and those that fail.
Error_Logs__Appsmith.gif (1440×810)

The triaging in our example above is especially useful when you have nested queries, several dependent bindings, and a more complex workflow overall.

Console Logs

console.log_in_the_Editor__Appsmith.jpg (1920×1080)

Just introduced in the Debugger, console methods in Appsmith help you see statements for just JS Objects and JavaScript bindings so much better than in the browser sub-window.

Set points in your code that you want to log statements at, view tabular data, or see groups for repeated errors.

System Logs

Post_7.jpg (1920×1080)

Automatically tracking all your interactions with Appsmith during build, System Logs show a helpful trail of activity by descending order of timestamp, especially useful when you want to go back in time or pivot from a point of failure to everything that led to it.

They show up for different situations and interactions for the type of entity you are working with.

With widgets, you see a log when you

  • Drag-and-drop a new widget on the canvas.
  • Update the widget’s properties
    Updating a property also updates all its dependent properties which then show up in System Logs.
Dependent_properties_updates_in_system_logs__Appsmith.gif (1280×720)
For example, when you update the tableData property, you also see its dependent properties like selectedRowIndex, filters, triggeredRowIndex, and so on.
  • Trigger events with an end-user action.
Trigger_events_with_an_end-user_action__Appsmith.gif (1280×720)
For example, when you are using an end-user action to store a value with storeValue or when you want a click-action to trigger an operation like an update or delete and are using onClick, you see them show up in System Logs.
  • Delete a widget from the canvas

With actions, you see them when you

  • Create a new datasource or a query
  • Update query properties like queryName, queryBody, queryConfiguration, and queryProperties.
  • Execute a query
Execute_a_query.gif (1440×810)
This can be either from query pane, running a plain REST API query, a JS Object, or via a widget’s bindings.
  • Delete a query

With JS Objects, you’ll see system logs when you

  • Create and update code inside JS Objects
  • Execute JS Objects
Execute_JS_Objects.gif (1440×810)

Just like errors, system logs are native to entities and have four parts to them.

Parts_of_a_system_log_line__Appsmith.jpg (1920×1080)

The timestamp

Logged as your entities are created, updated and deleted, these little breadcrumbs help you track back from when the error occurred to when it was last A-Okay.

Timestamped_logs_in_System_Logs.gif (1440×810)

The message

Useful during build, the message of the log answers two questions— what were you doing with an entity—creating it, updating it, deleting it—and what happened with your action—success or failure.

  • With widgets, outside of CRUD information, you also see event-specific info like onClick and showAlert linked to those widgets.
  • Queries and JS Objects are straightforward with start and end points that indicate if they were updated, ran, and failed.

The source

Like errors, a system log has two parts to its source—the entity’s name.the type of entity, e.g., SELECT1.TABLE1.WIDGET.

Redirect_from_an_Inspect_Entity_sub-window.gif (1440×810)
👌🏽 Appsmith Experience plug

Clicking the source from the logs takes you to the associated entity anywhere in Appsmith, be it a widget, a query, or a JS Object. Noice!

The response

This doesn’t always show, but when it does, it can be useful confirmation of a binding working, a query running successfully, or a JS Object executing completely.

  • For widgets, you see which properties are updated when you are configuring them and how.
    Say you’re updating the text widget’s background property and you don’t see it change on the canvas. Track the log to the response for a quick confirmation of that and troubleshoot the canvas next.
  • For queries, you’ll see two different logs—the start of a query run and the status of its execution.
    The first type of log will show you configuration details of the query—helpful to verify if the config matches the request.        

{
    "timeoutInMillisecond":10000
    "paginationType":"NONE"
    "encodeParamsToggle":true
    "body":"SELECT * FROM public."users" LIMIT 10;"
    "pluginSpecifiedTemplates":[
        0:{
            "value":true
        }
    ]
}

  • The second type will throw an error if the run fails. When the query runs successfully, it shows all the parameters that the query ran with and the time taken for the response.

{
	"response" : [...],
	"request" : {
		"actionId" "6321c1193668£71e£7caala2"
		"requestedAt" : 1663912830.640344
		"requestParams": {...}
}

  • With JS Objects, you see the response from the function as a JSON after an object is successfully run. This shows you how Appsmith handles the function while evaluating and running it and can be useful for spotting conflicts, undefined references, or troublesome variables.

Inspect Entity

Borrowing from a modern browser’s Inspect Element feature, Inspect Entity lets you see incoming and outgoing entities for any widget. These entities can be queries, JS Objects, or even other widgets.

Group_8480.png (1920×1080)
  • Incoming entities are those that fetch data from the datasource into the widget.
    For example, if the data on a table is populated by a Postgres query, you’ll see the query name under the Incoming entities column.
  • Outgoing entities are those that can specify the data that’s to be sent to the datasource in a typical CUD operation and then send it to your datasource.
    Say, a text widget is binded to a table's selectedRow property, you will see the text widget’s name under the Outgoing entities column.

The Inspect Entity pane lets you see dependencies for all your widgets on the canvas, especially useful if you have a medium-complex app with several widgets working off of each other. For example, when you have a parent widget or query that controls bindings on other dependent widgets---call them children widgets---, Inspect Entity can show you all those children when you click the parent and quickly take you to any one of them directly.

In combination with Errors, Logs and Inspect Entity round out the Debugger for several scenarios during build and save you hours in building an app end-users love. Try out the Debugger and let us know how you like it, what it's missing, and what we can improve. Our Discord is the best place for that feedback.

The Appsmith Debugger now supports Console methods
23
September
2022
Announcement

The Appsmith Debugger now supports Console methods

The Appsmith Debugger now supports Console methods
Rishabh Rathod
0
 minutes ↗
#
debugger
#
troubleshooting
#
console-methods
Announcement

For a while now, you have used and loved the Appsmith Debugger, nearly complete with a Error pane, system and error logs, and an entity inspector. We say nearly complete because it was missing one of the most popular debugging tools in a dev’s toolkit—console methods.

We are happy to announce the availability of console methods for both cloud users and self-hosters on v1.8.0.

“But, what is the Appsmith Debugger?”

Image_1.png (1920×1080)

Think of the Appsmith Debugger as a set of Chrome DevTools—like for Appsmith. It lives on the familiar 🐞 everywhere in Appsmith and

  • shows helpful error messages for bindings, queries, and variables
  • lets you inspect entity relationships
  • filters system and user logs

All of this is helpful when debugging unexpected API responses or app viewer experiences. Should you care to learn more, this post breaks down the debugger by each one of its features.

“Okay, and console methods are…”

Just one of the most popular ways of print debugging in modern browsers, console methods, exposed by the console API, are a set of functions that help you log the values of variables at set points in your code, messages, or even tabular data so you can investigate them in your browser’s debugging console.

Before today, you could use all supported browser console methods, but only in the browser’s dev tools sub-window. To any developer with their hands dirty with front-end code, the browser debugging subwindow is a necessary evil—a thousand lines of errors, messages, values, and steps that you would have to sift through. We are not going to say, “Looking for the literal needle in the haystack”, but you know you are thinking it.

“And the Appsmith Debugger has a console now?”

Yes! 🥳

So, instead of something like,

you now see,

Image_3.png (1920×1080)

Sweet? This gets sweeter.

Supported methods

  • log

Almost synonymous with console, the .log() method is one of the most popular ways to log a message or the values of variables defined in your Javascript.

It can also be used to show helpful messages or comments, say, the entry and exit points of functions.

Example


getUUID: () => {
		console.log("entry - getUUID function");
		let prefix;
		
		let d = new Date().getTime();
		console.log("new date created -", d);
		d += (parseInt(Math.random() * 100)).toString();
		console.log(d, "random number generated by getUUID")
		if (undefined === prefix) {
			prefix = 'uid-';
		}
		d = prefix + d;
		console.log("UUID created -", d);
		console.log("exit - getUUID function")
		return d;
	}

Result

Image_4.png (1920×1080)
  • error

the .error() method logs an error message to the Appsmith console, be it a a string like, “This is an error message” or the value of a function.

Say you've written a function and you suspect it’s returning an error., but you don’t know what kind. For unknown unknowns like this, `error` comes handy.

Example


checkTextWidget: () => {
		const element = Text1.text;
		if (element == "") {
			console.error("There is an error. The Text property is empty ");
		}
		return element;
	}

Result

Image_5.png (1920×1080)
  • warn

Jus as .error() aids error investigations, .warn() shows, well, warnings for known knowns. Some situations this can come in handy are,- When the evaluated value of binded data on a widget is not using the same datatype as the expected value- When widgets continue to use deprecated queries or functions- When the timezone used in a datetime functions doesn't match the browser’s

Example


selectDefaultValue: () => {
	 const defaultValue = Select1.selectedOptionValue;
		if (defaultValue == ""){
			console.warn("No values selected on Select1 widget ")
		}
		return defaultValue;
}

Result

Image_6.png (1920×1080)
  • table

table (.) just does what it says—logs a Table widget’s data in key-value pairs for rows as objects. While we support this in Appsmith, we are still working on a browser console-like table, especially as we make the Table feature-richer.

Example


table1DataFunc: () =>{
		const data = Table1.tableData;
		console.table(data)
}

Result

Image_7.png (1920×1080)

That’s it! You now have the power of the console right within in Appsmith. There are other useful views available under Logs and we'll talk about them in a follow-up to the Debugger teardown soon. Bookmark this page. Thank us later.

Debugging your app in Appsmith with the Appsmith Debugger, Part 1
20
September
2022
Product

Debugging your app in Appsmith with the Appsmith Debugger, Part 1

Debugging your app in Appsmith with the Appsmith Debugger, Part 1
Ayush Pahwa
0
 minutes ↗
#
product
#
errors
#
troubleshooting
#
debugger
Product

That title is a tongue twister, innit? Almost.

Here’s a meme that isn’t. It’s just the painful truth.

Debugging_is_like_being_lost_in_a_deser.jpg (749×500)

There is no perfect code, so you know debugging is inevitable, but it’s still a chore and is as crushing often times as the meme claims it is.

But, while debugging is inevitable, making it painful is optional, especially when you have the Appsmith Debugger. We have claimed we champion developer experience as many times as we could before without being brazen about it. We think. So, we thought some more and said, “Let’s prove the claim, too.”

“Wait, wait. What is the Appsmith Debugger?”

In 2021, we shipped the Appsmith Debugger, a set of Chrome DevelTools-like features that have helped you investigate and resolve errors in Appsmith.

We recorded a video for it in a series about the Debugger, talked about it in our docs, and referenced it enough times to make you groan about our obsession with errors. If this is the first you are hearing of it, get on our Discord so we can tell you some more about it.

Why we did this

Browser dev tools are as helpful as a magnet when looking for iron fillings in a pristine haystack. To the untrained eye, they can be downright criminal, too.

Browser_debugger.jpeg (960×506)
Source: Reddit

Sure, sure, they nest groups of errors and there are separate tabs for the console and the debugger, but meh! There’s a sea of error messages, system logs, console logs, and then there’s you swimming in it.

Before we shipped the debugger, you saw,

  • errors inside a widget's Property pane that floated on your canvas which probably already had several widgets
  • the Editor’s Response pane, which clubbed legit responses with errors

The Debugger solved several of those problems.

Post_8.jpg (1920×1080)

What’s the Debugger have

Available on app.appsmith.com and our self-hosted release images, it can be called by toggling the debug icon—the one that looks like a bug—on the bottom-right corner of your Appsmith screen or with CTRL/CMD +D.

Inside the Debugger, live three panes, Errors, Logs, and Inspect Entity, each with their own uses. In the first part of this two part post, we will break the Error pane down for you and see how it can save you hours over browser dev tools in debugging.

If you would much rather just learn about Logs and Inspect Entity, bookmark this post. We will link to Part 2 in five days. :-)

Errors

Borrowing from a browser’s dev tools sub-window but improving on it radically, the Error pane lists all errors that we see when you are building inside Appsmith. Familiar examples include syntax errors from JavaScript bindings, reference errors from queries, and datatype mismatch errors.

Errors in the pane are specific to an Appsmith entity. Translated from Appsmithlish, it means you see helpful error messages about a faulting widget, a rogue query, or a stubborn JS Object.

Untitled.gif (1440×810)
Example of a faulting widget and the error beaconing it
Untitled.gif (1440×810)
A JS Object error

  • These errors get logged to the pane in lockstep with the sequence of code execution in Appsmith.
  • The Error pane is the default view when working with widgets—most noticeable if you have the Debugger sub-window resized as in the pictures in purple—so you know what’s going wrong and where in real-time.
  • The Editor's Error Pane is smarter. It doesn’t automatically switch to the Error pane—Response is the default on this screen—when an error occurs. Instead, the Debug icon lights up in red with a numeric notification that’s like a running ticker for the number of errors the Debugger sees with your queries or JS Objects. Click it to open the Error pane.
  • Every error you see in the pane follows a template with a few helpful pieces of info to help you debug.
image_high.jpeg (1920×1080)
Numbers on this image correspond to bullets below. Images in sub-bullets below show what the sub-bullet talks about.

The timestamp

Logged as your code executes or a value evaluates with your widgets, these little breadcrumbs help you track back from when the error occurred to when last it was A-Okay.

The issue

Depending on the error type, you will see a couple different kinds of issues.

  1. With widgets, you’ll see the faulting widget property’s name. An example of this is the commonplace The value at tableData is invalid, occurring when the property tableData expects an Array<Object> datatype but you have an Array<List> instead.
  2. With queries, you see more specific errors, often specific to the datasource you are running your queries to, often indicated by status codes returned by your failing requests.
  3. With JS Objects, we straight-up level with you about the parseability of your functions. Parseability probably isn’t a word, but you know what we mean.

The source

This has two parts to it—the entity’s name.the type of entity the troublesome one is, e.g., SELECT1.WIDGET. As is obvious and has been to you, SELECT1 is the entity’s name and WIDGET is the entity type.

👌🏾 Appsmith Experience plug: Clicking the source takes you to the faulting entity anywhere in Appsmith, be it a widget, a query, or a JS Object. Noice!

The message

This is the most helpful part of the message, beginning with Error and ending with a helpful bit of text or a number.

  1. Because widgets bind to queries or JS Objects using JavaScript, quite a few errors you see are the same as familiar JavaScript errors like SyntaxError or TypeError. Some other errors show is not defined. This is when a variable, a query, or a JS Object isn’t defined, but you have specified it in the Property pane.
  2. In the Editor, these messages go a step further and call out the line number in the editor that has the faulting code. For example, Line 2: Unrecognized token '$'. This type of message has three parts to it.
Post_9.jpg (1920×1080)

1. The type: Error

2. The string: relation “public.user” does not exit

3. The line number: Position 15

😻 Appsmith Experience plug: Clicking the message will open our in-app docs finder and run a helpful search to show you top docs matching the error.

Response from queries or bindings

This doesn’t always show, but when it does, it can show you helpful responses with query params or evaluated values of data bindings.

Post_10.jpg (1920×1080)
  1. With widgets, you’ll see the evaluated value from the bindings.
  2. With queries, you’ll see the payload from the API you are querying.

“How does all of this help?”

Consider two situations we have painfully drawn for you.

State #1

You have several queries and widgets on your way to a complete build.

Condition #1

You have nested queries inside JS Objects. Meaning, these queries are binded to multiple widgets via JavaScript transformations and have dependent parameters with each other.

Scenario #1

A query fails and returns an error.

Without the Appsmith Debugger

You decide to sift through the browser dev tools sub-window, trying to locate the faulty query in something that looks like ↓.

The_browser_console.png (1920×1080)

When you find the first problem query, you’re hoping against hope this is your patient zero.

  1. If so, congratulations aren’t quite in order yet. You’re still going to have to surgery the query to see what went wrong where.
  2. With browser tools, may you be lucky and find a fix in the first hour.

Most times, though, Murphy’s Law applies.

  1. Meaning, you will need to find the last problem query.
  2. Repeat steps #1 and #2 with all the sub-steps in between

If you have a friend who’s on Appsmith, you hear them say, “Good morning. Do you have a ready app? No? Try the Debugger. 🙄”

With the Appsmith Debugger

You see all the errors from all the failed queries In the Error pane and nothing else to crowd your investigation.

  1. You quickly scan by the type of errors.
  2. Errors are listed in the sequence of query execution.
Post_11.jpg (1920×1080)
So you can simply scroll to the first failed query, and investigate further.

  1. The error message tells you what failed with the params in which line, neatly indented neatly for you.

Don’t remember the query’s name? Pfft! We got it. Click the error message, and go right to the error source.

Trouble troubleshooting? Click the error message and find super-relevant docs in Appsmith’s doc finder.

At the end of it, you save a whole night’s hair-pulls, wake up bright and fresh, sip your coffee, and wonder why some people still use browser dev tools. 🤔 Maybe you should refer them to us.

State #2

You have the data from a REST API and the table for your dashboard, but you have left the chart for the very end. You are sensible like that. Charts are tricky things in general.

Condition #2

You have to bind the chart widget from Fusion Charts or one of our defaults with a query that should output the format Array<{ x: string, y: number Required }> as input to the widget. This will need JavaScript transformations.

Scenario #2

You get a datatype mismatch error.

Without the Appsmith Debugger

You toggle around the floating EXPECTED STRUCTURE, EXPECTED STRUCTURE - EXAMPLE, and EVALUATED VALUE panes to understand the chart widget’s configuration.

You have a JS Object for the transformation, so you now switch back and forth between the canvas and the JS Editor for each possible fix in the JS code.

  1. By now, you have console.loged your way to the browser tools sub-window. Magnet, meet Iron Fillings In A Haystack.
  2. Forgot the change you made to the JS Object five tries ago? Yeah, well, no System Logs, so what can you do, right? Maybe note each change on Sublime or VS Code from this point on.

With the Appsmith Debugger

Post_12.jpg (1920×1080)

Right after you run the transformation, you see the floating-pane-that-we-don’t have-a-name-for-yet show you some red and the Error pane light up with all your errors, timestamped and sequenced by the order of code execution.

  1. You see the type of error and the evaluated value for the faulting entity. Stick to this without worrying about the unnamed floating pane.
  2. Your query has trouble getting a response from your datasource, so you see that error, but hey, you also see the binding failure of that same query with the widget.
  3. No hunting for the query or the widget you want to troubleshoot. One click from the Debugger and you are transported to the associated entity.
Debugger_with_click-actions__JS_Editor.jpg (1920×1080)

You see all the errors from the transformation in one pane with click-actions for each one of them.

Docs_finder_from_Response__Appsmith.gif (1440×810)

Error messages not enough? Click the error and choose, Browse code snippets, and voila! You now now search for the chart + the query right there and see some of our helpful docs.

Made it to here? Your life inside Appsmith is going to change.

Also, this is just part one of this two-part breakdown. What’s next?

https://media.giphy.com/media/3kIGmlW0lvpnmF3bGy/giphy.gif

Better than post-credits. A whole other movie featuring Logs and Inspect Entity. Meanwhile, here’s a few things you can do.

Until the next Debugger post, Appsmiths.

P.S.: We love you.