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QMLEngine

new QMLEngine(element)

  • element {HTMLElement}

Returns new QMLEngine object.

There could be only one running QMLEngine at the moment.

engine.start()

Start the engine/application.

engine.stop()

Stop the engine/application.

Restarting is experimental.

engine.loadFile(file[, parentComponent]) {

  • file {String} Path of file to load.
  • parentComponent {Object} Parent component.

Load a .qml or .qml.js file, parse and construct.

engine.loadQML(src[, parentComponent [, file]]) {

  • src {String} QML source.
  • parentComponent {Object} Parent component.
  • file {String} Optional file name for debug purposes.

Parse and construct QML.

engine.loadQMLTree(tree[, parentComponent[, file]]) {

  • tree {Object} Parsed QML tree (see qmlweb-parser).
  • parentComponent {Object} Parent component.
  • file {String} Optional file name for debug purposes.

Construct from an already parsed QML tree.

engine.rootContext()

Get the top-level context of the context hierarchy.

engine.size()

Returns the dimensions of the root object, in format { width: 100, height: 100 }.

engine.loadImports(imports[, currentFileDir])

  • importsArray {Array} Import statements.
  • currentFileDir {String} Base directory for imports lookup.

Performs loading of qmldir files from given qml import records.

importsArray is in qmlweb-parser notation, e.g. [import1, import2, ...] where each importN is also an array: ['qmlimport', 'name', version, as, isQualifiedName].

currentFileDir will be used together with importPathList(). It defaults to base path extracted from the initially loaded file path.

Implicit input

  • engine object function importPathList() - list of urls bases used for qmldir files lookup

Additional implicit input/output

  • engine object variable qmldirsContents - used for caching, e.g. memory for previously loaded qmldir files

Output

  • engine object variable qmldirs - new records will be added there

Return value

  • nothing

Details

For each of given import statements, loadImports

  1. computes qmldir file location according to http://doc.qt.io/qt-5/qtqml-syntax-imports.html
  2. calls readQmlDir for actual reading and parsing of qmldir file content
  3. gets external declarations of that qmldir file and pushes them to engine.qmldirs hash.

engine.qmldirs is a hash of form: { componentName => componentFileUrl } This hash then used by qml.js::construct method for computing component urls.

Notes

  1. This method is not suited for loading js imports. This may be done probably after answering to Q1 (below).
  2. Please look for additional notes at readQmlDir function.

QNA

  • Q1: How and where in engine component names might be prefixed? E.g. names with dot inside: SomeModule.Component1

  • A1: Seems it doesn't matter. Seems we may just save name with dot-inside right to qmldirs, and it may be used by construct() seamlessly. Check it.

  • Q2: How we may access component object from here, to store qmldirs info in components logical scope, and not at engine scope?

  • A2: Probably, answer is in Component.js and in QmlWeb.loadImports

TODO

  • We have to keep output in component scope, not in engine scope.
  • We have to add module "as"-names to component's names (which is possible after keeping imports in component scope).
  • Determine how this stuff is related to QmlWeb.loadImports
  • Check A1
  • Make a complete picture of what going in with imports, including Component.js own imports loading.
  • Note importJs method in import.js