052 Automated database updates in Joomla during development of a component

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Amigo edited this page Jul 26, 2019 · 9 revisions

AUTOMATED DATABASE UPDATES IN JOOMLA DURING DEVELOPMENT OF A COMPONENT

Demonstration - Creating, Updating And Adding Database Tables

I would like to give you a explanation as well as demonstration of how JCB deals with Joomla's implementation when it regards to creating of Database tables, as well as updating them or even adding more. Joomla is a way of doing this through specific file convention within your components file structure package. JCB is also been designed to detect changes in your components development 00:00:37 and create those files for you. The best way to illustrate this is let's compile a component. We have Sermon Distributor. Let's going to compile that for us. Then we'll go to the zip file, unzip it. Have a look at it, and see those files extracted here. 00:01:04 Inside of this(com_sermondistributor) we have an admin folder and inside admin folder a sql folder. Here(installmysql.uft8.sql) is the first file of interest that's what Joomla uses to build a database upon the first install of the component.

Runs Only On Fresh Install - Thereafter It will Not Run Again

Do take note that it runs this file only on a fresh install of the component, thereafter it will not run it again, even if that's file gets updated, even if more values get added and usually it does, JCB updates this file as you create new views which in then it means a new table, and if you add Fields which means a new column or field in the database. 00:0So1:46 This file will update but it is for those clients of yours that is going to install the component for the first time. All those who already have the component installed, this file will mean nothing to them. All the files in this update folder is what would be relevant. If you have a client which has version 1.3.2 installed on his system, and he gets this package from you this 2.0.0 00:02:14 package, it will start with 1.3.2 file, then 1.3.3 and so forth. It will start with a file which is the same version as the version that is currently installed on the Joomla website. 00:02:34 That means JCB builds these files in that expected way.

Making Changes - JCB Updates

Now let's go make a change to the component and see how JCB updates these files. I'm going to install the component so we have it in the database. We can look at the database in the moment to see how things change. I'm going to open the Admin Views and I'm going to add 00:03:07 a field to the Admin View called Sermon. It's going to be any generic field, so that we can at least see it in action. I'm going to call it Mobile Phone, and put in the fourth position, the left tab, that's not really important. We added a field.

Add A New View - JCB Combines These Values In One Update

Now you could at this point also add a new view and JCB will detect both of them and will add both of them to the update file. You could even do that make this change, run the compiler, have this new update, then make another change, run the compiler, and it'll follow along incrementing the version 00:04:01 value of the component as you go. Just for our sake, maybe let me add a view, already in another view and then you'll see how JCB combines these values into one update. I'm going to grab a view that isn't already part of this component and just for illustration. 00:04:26 Save and close. There we go we have a view and a new field. If we compile the component now, it will do all those things that I've explained. There you see it's incremented into 2.0.1 and if we go to the zip file, again extracted, open it up, admin, sql, updates. 00:04:53 We see there is a new file. Let's open this file, just investigate a little. We see here's the command to add that new field and here is another one to create that new table. All of that is been placed into this 2.0.0 00:05:16 file which like I said is the current version of this installed component. If we look at the database at this point you will see there is no Look table. If we look at the Sermon table and Structure then we see that there is you no 00:05:36 Mobile field. Let's install it now and see the change. It's been successful, go back to the table. Let's just refresh this. There you have it, got field added. If we go back to the new table that it had to create, and there is the new table. It's done both of those as expected.

Component Automatically Incremented Its Version Number

Secondly let me show you where it made some changes in JCB to relation to this component. You'll see that the component has automatically incremented it's version number. If we open this component updates area. You'll see that it has dynamically stored that same values that we saw on the file, next to the correct version, and it has created a new version entry. You have to manually update this URL. As there are too many variations here we couldn't implement this dynamically. 00:06:49 This URL is what is being used in your updates server file, if your component is set to have an update server file. At this point you can now continue even adding another view or even another field and it'll just the same it'll increment it and it will update your database upon installation. That is as simple as it is. There are some places where that behavior may not function as expected.

Some Places That The Behavior May Not Function As Expected

The only one I'm very much aware of is the one that happens when you import or export a component from one JCB to another. Those of you that have used this you can export a component and then import it again. That effectively creates all the data in the relation to JCB, but it doesn't recreate the history and the asset IDs and everything else which is related to its integration within the Joomla interface or database.

Example - Only Way To Start History - Open It - Save And Close It

That means for example your there is no history regarding the admin views. The only way to start any history for that view would be to open it, and to save and close it. That's the only way. Now that specific area will have a history track. Same goes with the admin views. You have to open them and save them. This one not the admin view itself but the fields of the admin view. 00:08:36 Open them, save them again. This will create its first entry and serve as a reference point to the last time to which those values were changed. If you compile the component at that point it will add two component IDs to that specific entries, and use it as a reference point like I've said. Then having after compiled it you first saved them, then compile the component and then only start making your changes. You'll bring the component into the motion of what would be the natural 00:09:16 flow of development. This natural flow that you would create a component, add views, then add fields to it, all along saving, closing, saving. That generates the history values that we need to detect changes. If you import a component none of those values exist and so it won't behave as expected. Well that's just a heads up. I supposed many of you might not even have this issue but if you do, you will know at least where to look and what to do to fix it. 00:09:51 That is a quick overview of JCB's implementation to correspond to Joomla's conventions in creating tables and updating them dynamically through the SQL files in the updates folder. I hope that 00:10:16 this is going to be helpful to those who may not have understood this before.