This is a really cool, simple method for sketching out what you want your code to do. I came across this flowcharting method from page 23 of the great book “Javascript and JQuery” by Jon Duckett (screenshots below). He describes the motivation for them like this:
“Often scripts will need to perform different tasks in different situation. You can use flowcharts to work out how the task fit together. The flowcharts show the paths between in step.”
“Often scripts will need to perform different tasks in different situation. You can use flowcharts to work out how the task fit together. The flowcharts show the paths between in step.”
The flowchart allows you to see all the different paths of actions a user can take, and how the application should respond. Let's take a look at the key:
In the following example we can see a simple diagram that displays the flow logic for a simple form validation function with some explanation beneath it.
1. The button is clicked which sends an event to trigger your onButtonClicked function.
2. Then you need to access the specific textfield in question and save it's vale.
3. Now the application must make a decision. It needs to compare the value from (2) to some predetermined conditions and see if it is valid. In this example there are only two possible paths, but there may be more.
4. If there is not a name (or valid entry) in the textfield display a message to the user. Then wait for them to hit the button again to trigger the event and start the flow over again.
5. This is neither a decision, event, input, nor output. It's just a calculation done to get the data is a way we can present more easily.
6. Actually present the data to the user and show it on the screen.
2. Then you need to access the specific textfield in question and save it's vale.
3. Now the application must make a decision. It needs to compare the value from (2) to some predetermined conditions and see if it is valid. In this example there are only two possible paths, but there may be more.
4. If there is not a name (or valid entry) in the textfield display a message to the user. Then wait for them to hit the button again to trigger the event and start the flow over again.
5. This is neither a decision, event, input, nor output. It's just a calculation done to get the data is a way we can present more easily.
6. Actually present the data to the user and show it on the screen.
I do believe that this flowcharting technique a really interesting way to flesh out what things you want the application to do in response to different events. It’s much more simplified than something like UML, and writing feels more like you're thinking from the user’s perspective. I’m not saying you shouldn’t write UML once you want to start coding. I’m just saying that it might be a good exercise to build out a quick flowchart of your application before starting to write that UML (or diving into the first unit tests). It's a lean, quick way to outline what the software should do, and it works very nicely on a whiteboard or google drawings. What do you think about this flowchart technique?
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