doTemplateRender abstract method
- required TemplateManager templateManager,
- required String anchor,
- required List<
List< contexts,BeagleDataContext> > - BeagleUIElement componentManager()?,
- TreeUpdateMode? mode,
Renders according to a template manager and a matrix of contexts.
Each line in the matrix of contexts represents an iteration and each column represents the value
of a template variable. For instance, imagine a template with the variables @{name}, @{sex}
and @{address}. Now suppose we want to render three different entries with this template.
Here's a context matrix that could be used for this example:
[
{ id: 'name', value: 'John' }, { id: 'sex', value: 'M' }, { id: 'address', value: { street: '42 Avenue', number: '256' } },
{ id: 'name', value: 'Sue' }, { id: 'sex', value: 'F' }, { id: 'address', value: { street: 'St Monica St', number: '85' } },
{ id: 'name', value: 'Paul' }, { id: 'sex', value: 'M' }, { id: 'address', value: { street: 'Bv Kennedy', number: '877' } },
]
Note that the parameter contexts adds to the context hierarchy that is already present in the
tree, it doesn't replace it, i.e. you can still use the contexts declared in the current tree.
For each line of the context matrix, a template is chosen from the template manager according to
case, which is a boolean or a beagle expression that resolves to a boolean. When case is an
expression, it's resolved using the entire context of the current tree plus the contexts passed
in the parameter contexts corresponding to the current iteration. If no template attends the
condition the default template is used. If there's no default template, the iteration is skipped.
After processing all items, the resulting tree is attached to the current tree at the node with
id anchor (passed as parameter).
The component manager is an optional parameter and is used to modify the resulting component. This can be very useful for managing ids, for instance. The component manager is a function that receives the component generated and the index of the current iteration, returning the modified component.
@param templateManager templates used to render each line of the context matrix.
@param anchor the id of the node in the current tree to attach the new nodes to.
@param contexts matrix of contexts where each line represents an item to be rendered according to
the templateManager.
@param componentManager optional. When set, the template result goes through this function before being
finally rendered.
@param mode optional. when viewTree is just a new branch to be added to the tree, the mode must be
specified. It can be append, prepend or replace. The default value is replace
Implementation
void doTemplateRender({
required TemplateManager templateManager,
required String anchor,
required List<List<BeagleDataContext>> contexts,
BeagleUIElement Function(BeagleUIElement, int)? componentManager,
TreeUpdateMode? mode,
});