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Implemented in Osm Admin:

• new ALTER TABLE algorithm
• NULL to non-NULL data conversion
• new query test suite

This time, I tackled adding an explicit property to an existing table, and then making it non-nullable.

It raised the need for data conversions - additional handling of the existing data - or otherwise, the database engine fails, or the data becomes invalid.

And it made me split migrations in two parts - the one that runs before the data conversion, and the other one that runs afterwards.

While working on diff algorithm I noticed a certain pattern that I use over an over again.

Using this pattern, I implemented notification table diff.

Finally, I rearranged diff/migration code for better code readability.

Yesterday, I moved the table creation code into new schema diff migration engine.

Now, working on notification table migrations.

This time:

• I found out that the whole search index creation should be done during indexing, not migrations.
• I refactored diff algorithm and made it much easier to read.

Before digging into property diff algorithm, let's dig into how exactly it's used, and what other property-related logic is there.

Yesterday, I continued working on schema migrations:

• implemented table diff algorithm;
• took into consideration table renames.

After a system update, I've got some problem with my laptop, and one thing to check was system log files.

This got me thinking: what makes a good log for my own application? And I think that application logs are as useful as they are able to answer potential questions I may have when an application is in production.

Let's think what kind of questions I might have, and what information might be useful to answer them.

Recently, I fixed numerous issues to make the first migration tests work.

Then, I started implementing the schema diff algorithm - the basis for schema migrations.

More dots got connected in the schema migration design, see this post for details.

Then, I tried to return to TDDing it, but strange errors met me there, so I left them to be resolved in the next piece.

Schema migrations are going to be generated and executed automatically under gulp watch. It will result in lots of tiny migrations: add a column, change its type, make it not nullable, and so on.

It's convenient during development, but it might be not optimal to reapply in production. Indeed, it's better to convert a large table to new structure all at once rather than running a conversion for each of the tiny migration.

This observation contradicts the previously stated migration workflow, so let's update it.

In spirit of TDD, I started with a meaningful, but failing test that is reasonably fast. Then, I worked to make it green:

• implemented the loading of schema fixtures from the codebase;
• worked on generating migration files.

After drafting some ideas of how the schema migrations should actually work, let's start implementing it in TDD way.

The goal of the current iteration is to adjust the database schema and preserve/convert existing data according to any changes in schema classes, grids, forms or indexers.

This post presents some thoughts how it might work with class definitions.

After finishing the iteration "#17 Minimum UI", I revisited the goals and the scope of the minimum viable product, and picked the most pressing task for the next iteration - "#18 Database Schema Changes".

I implemented the last user action that is typical to a CRUD application - object deletion.

Done:

• routes responsible for creating new products, and modifying existing products
• incremental indexing
• cloning query objects
• INSERT INTO ... SELECT ... statements

Last two weeks were about implementing initial version of an Osm Admin grid, integrating it seamlessly with the editing form, and enabling mass-editing of multiple objects.

After finishing it, I realized that Osm Admin had become bigger than Osm Framework! To keep up, I started writing docs for it.

And now, you have a step-by-step guide for creating a project, adding Osm Admin to it and a practical example of an admin area that you can copy to your project and try it out locally.

Recently, I implemented mass-editing in Osm Admin. It allows you to view and edit multiple objects in a single operation.

This article describes mass-editing of products in a typical e-commerce application.

The last 4 weeks were mostly a vacation. It's been a time for reflection, but still, I delivered some new features.

In Osm Admin, forms already allow creating new objects and saving them to the database, and editing one or several existing objects.

I've also implemented URL query filters that are applied to the underlying database query and that can be displayed in the user interface.

From now on, Osm Framework and all projects built with it - can be installed and developed under Apache and on Windows.

In the user interface, you can narrow displayed data using grid column filters, or filters displayed in the sidebar. To enable that, apply #[Filter\*] attributes to class properties.

Applied filters appear in the URL query parameters, for example, .../edit?id=5+16+19, and on the page.

You can apply filters not only to a grid page, but also to a form page - to mass edit all matching objects, or to an action URL (edit, delete, or custom) - to perform the action on all matching objects.

In the same way, you can apply filters to the API URLs in order to retrieve or modify matching objects in a script.

In Osm Admin, I've finished indexing. It means that whenever you modify an object in the database, the changes are automatically propagated to all dependent indexed properties in the database.

I've also introduced a grid/form pair as the main user interface concept that is optimized for performing operations on multiple objects. There is also a programming interface (API) that will internally work in the same way, but without visuals. I implemented a part of this interface - an object creation form.

Osm Framework and all projects built with it - including this website and Osm Admin - are upgraded to TailwindCSS 3.0.

Today, I finished implementing an object creation form.

It works according to the specs on Interfaces and Forms. Currently, it only supports string and integer input fields; later, there will be a lot more.

Let's review how it works.

In Osm Admin, a form is an integral part of the class user interface. It's a very specific kind of HTML form.

In this article, I'll review what's in a class form, and how it's reflected from the application code.

Yesterday, I described a user interface pattern for managing data of a certain data class using a grid/form pair. Let's call this grid/form pair class interface in the admin area.

In this article, I'll examine what moving parts are inside a class interface.

So far, I've been concerned about how application data is modeled, stored and handled internally.

Yet, the final objective a user interface for viewing and editing it visually.

Let's dream a bit about how it might look like.

Yay, indexing works!

It's changed quite a bit, so let's review how it works from the very beginning.

For the last two weeks, I figured out two core features that will allow Osm Admin to stand out from other CRUD applications:

1. It will allow mass editing of data objects.
2. It will automatically propagate data changes throughout the database.

The foundation for the mass editing feature is data queries. Data propagation will be ensured via indexing.

I've been working on the Osm Admin indexing engine, and it's still in progress. While working on it, I reworked the inner working of data queries. Finally, I've achieved a very clear separation of various Osm Admin concerns, and documented it.

In Osm Core, I added reflection over class methods.

I'm still working on indexing, and it seems to get one more refactoring. But more on that later.

Meanwhile, let's review Osm Admin modules, their responsibilities and dependencies.