@Test
public void pushResolver() throws IOException {
ValueResolver resolver =
new ValueResolver() {
@Override
public Object resolve(final Object context) {
return 1;
}
@Override
public Object resolve(final Object context, final String name) {
return 1;
}
@Override
public Set<Entry<String, Object>> propertySet(final Object context) {
return null;
}
};
Map<String, Object> hash = new HashMap<>();
hash.put("foo", "bar");
Context ctx = Context.newBuilder(hash).push(resolver).build();
assertEquals("bar", ctx.get("foo"));
assertEquals(1, ctx.get("bar"));
}
/**
* Lookup the given key inside the context stack.
*
* <ul>
* <li>Objects and hashes should be pushed onto the context stack.
* <li>All elements on the context stack should be accessible.
* <li>Multiple sections per template should be permitted.
* <li>Failed context lookups should be considered falsey.
* <li>Dotted names should be valid for Section tags.
* <li>Dotted names that cannot be resolved should be considered falsey.
* <li>Dotted Names - Context Precedence: Dotted names should be resolved against former
* resolutions.
* </ul>
*
* @param key The object key.
* @return The value associated to the given key or <code>null</code> if no value is found.
*/
public Object get(final String key) {
// '.' or 'this'
if (MUSTACHE_THIS.equals(key) || THIS.equals(key)) {
return model;
}
// '..'
if (key.equals(PARENT)) {
return parent == null ? null : parent.model;
}
// '../'
if (key.startsWith(PARENT_ATTR)) {
return parent == null ? null : parent.get(key.substring(PARENT_ATTR.length()));
}
String[] path = toPath(key);
Object value = get(path);
if (value == null) {
// No luck, check the extended context.
value = get(extendedContext, key);
// No luck, check the data context.
if (value == null && data != null) {
String dataKey = key.charAt(0) == '@' ? key.substring(1) : key;
// simple data keys will be resolved immediately, complex keys need to go down and using a
// new context.
value = data.get(dataKey);
if (value == null && path.length > 1) {
// for complex keys, a new data context need to be created per invocation,
// bc data might changes per execution.
Context dataContext =
Context.newBuilder(data).resolver(MapValueResolver.INSTANCE).build();
// don't extend the lookup further.
dataContext.data = null;
value = dataContext.get(dataKey);
// destroy it!
dataContext.destroy();
}
}
// No luck, but before checking at the parent scope we need to check for
// the 'this' qualifier. If present, no look up will be done.
if (value == null && !path[0].equals(THIS)) {
value = get(parent, key);
}
}
return value == NULL ? null : value;
}
@SuppressWarnings("unchecked")
@Override
protected void merge(final Context context, final Writer writer) throws IOException {
if (body == null) {
return;
}
final String helperName;
Helper<Object> helper = helper(name);
Template template = body;
final Object childContext;
Context currentScope = context;
if (helper == null) {
childContext = transform(context.get(name));
if (inverted) {
helperName = UnlessHelper.NAME;
} else if (childContext instanceof Iterable) {
helperName = EachHelper.NAME;
} else if (childContext instanceof Boolean) {
helperName = IfHelper.NAME;
} else if (childContext instanceof Lambda) {
helperName = WithHelper.NAME;
template =
Lambdas.compile(
handlebars,
(Lambda<Object, Object>) childContext,
context,
template,
startDelimiter,
endDelimiter);
} else {
helperName = WithHelper.NAME;
currentScope = Context.newContext(context, childContext);
}
// A built-in helper might be override it.
helper = handlebars.helper(helperName);
} else {
helperName = name;
childContext = transform(determineContext(context));
}
Options options =
new Options.Builder(handlebars, helperName, TagType.SECTION, currentScope, template)
.setInverse(inverse == null ? Template.EMPTY : inverse)
.setParams(params(currentScope))
.setHash(hash(context))
.build();
options.data(Context.PARAM_SIZE, this.params.size());
CharSequence result = helper.apply(childContext, options);
if (!isEmpty(result)) {
writer.append(result);
}
}
@Override
public CharSequence apply(final Object context, final Options options) throws IOException {
if (context == null) {
return null;
}
if (options.params.length <= 0) {
return context.toString();
}
Context ctx = Context.newBuilder(options.context, context).build();
Object lookup = ctx.get(options.param(0).toString());
if (lookup == null) {
return null;
}
return lookup.toString();
}
/**
* Lookup the given key inside the context stack.
*
* <ul>
* <li>Objects and hashes should be pushed onto the context stack.
* <li>All elements on the context stack should be accessible.
* <li>Multiple sections per template should be permitted.
* <li>Failed context lookups should be considered falsey.
* <li>Dotted names should be valid for Section tags.
* <li>Dotted names that cannot be resolved should be considered falsey.
* <li>Dotted Names - Context Precedence: Dotted names should be resolved against former
* resolutions.
* </ul>
*
* @param key The object key.
* @return The value associated to the given key or <code>null</code> if no value is found.
*/
public Object get(final String key) {
if (".".equals(key) || "this".equals(key)) {
return model;
}
if (key.startsWith("../")) {
return parent == null ? null : parent.get(key.substring("../".length()));
}
String[] path = toPath(key);
Object value = get(path);
if (value == null) {
// No luck, check the extended context.
value = get(extendedContext, key);
// No luck, but before checking at the parent scope we need to check for
// the 'this' qualifier. If present, no look up will be done.
if (value == null && !path[0].equals("this")) {
value = get(parent, key);
}
}
return value == NULL ? null : value;
}
/**
* Look for the specified key in an external context.
*
* @param external The external context.
* @param key The associated key.
* @return The associated value or null if not found.
*/
private Object get(final Context external, final String key) {
return external == null ? null : external.get(key);
}
@Override
Object doParse(final Context scope, final Object param) {
return scope.get((String) param);
}