Getting a specific list element

[d_stranz]

Unfortunately, I find that the documentation on Qt Quick and QML to be sadly insufficient. What's there is either so basic as to be useless or so involved that it is impossible to understand. When I was looking at XmlListModel last night, the link takes you to a generic List model page that describes all of the various QML list models. The links on -that- page for more information on XmlListModel take you right back to the same page.

The best I can suggest is to go to the Qt Quick Examples and tutorials and start studying things that sound like they might be useful.

[schu4647]

So it turns out I am using QtRpi which uses QT5.7 cross compiled from a Linux machine to a raspberry pi. XML is not a supported module.

I do think I found the answer in the stocqt project. In StockListView.qml they do the following.

First they declare these variables up top

property string currentStockId: ""
property string currentStockName: ""


Then they use a model.get to get the data for the active element.
onCurrentIndexChanged: {
if (currentItem) {
root.currentStockId = model.get(currentIndex).stockId;
root.currentStockName = model.get(currentIndex).name;
}
}

I was playing with it and it pulls the element that is active in currentIndex. I can't try it with my stuff until Monday. My wife will kill me if I mess with this on the weekend.

[d_stranz]

XML is not a supported module.

Surprising. The Qt source code is available, so you could try building the XML module yourself if you are adventurous. If you are more adventurous, you can install a native compiler toolchain on your RPi and build it there instead of cross-compiling.

In any case, you don't really need XML, it is just a convenient way to store hierarchical data in a readable and easily parseable way. You could also use SQLite to make a recipe database; SQLite is implemented as a single source / header pair and you simply compile it as part of your project. You don't even need the database support from Qt.

A database might contain three tables:

- A Recipes table, with fields for RecipeID, Name, Description, and whatever else
- An Ingredient table, with fields for Ingredient ID, Name (this table is independent of recipe - the same ingredient can appear in more than one recipe)
- A RecipeIngredients table linking RecipeID and IngredientID, with fields for Quantity and Unit

From the list view containing recipes, when the user clicks a recipe line, retrieve the RecipeID by searching the Recipes table for the Name.
From the RecipeIngredients table, retrieve all IngredientID entries where RecipeID matches
From the Ingredients table, retrieve the Name for each matching IngredientID and display them in the ingredients list view.

My wife will kill me if I mess with this on the weekend.

"Honey, I'm trying to improve my skills so I can find a better job and make more money so we can have better vacations... I don't have the time to do this during the week."

[high_flyer]

in addition to d_stranz's answers:

I would would pack the whole data in to one treemodel.
Each recipe is a child of the root element - and it contains the name of the recipe.
Each recipe element is a parent to ingredient elements.

Also, remember that how data is stored and how it is in memory can vary, and it often does differ.
I'd do what would be the easiest thing to do, for me.
If you are very strong with XML, do it in XML, if you are strong with MySQL, you can do in MySQL, etc
I would do it in a text file, using QSettings.
Its easy, and you can open it with any editor and still know what the data is, and even mend it manually if needed.
Well, I am a C++ guy, so if you have found something else that works for you better with QML, stick with it, here is just another view on things, maybe it can give you some ideas, maybe not.

As I said, in memory I'd use a tree-model and in your recipe list I'd simply show the first level of children (the recipe names).
For each selected recipe I'd get the list of its children and show that in a list of ingredients at the bottom.

Since you have asked about QML documentation here is a good link if you don't know it yet:
https://qmlbook.github.io/
And for your case you probably would like to jump to:
https://qmlbook.github.io/en/ch06/index.html