com.day.cq.commons.JS Maven / Gradle / Ivy
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/*
* Copyright 1997-2010 Day Management AG
* Barfuesserplatz 6, 4001 Basel, Switzerland
* All Rights Reserved.
*
* This software is the confidential and proprietary information of
* Day Management AG, ("Confidential Information"). You shall not
* disclose such Confidential Information and shall use it only in
* accordance with the terms of the license agreement you entered into
* with Day.
*/
package com.day.cq.commons;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Collection;
import javax.jcr.Node;
import javax.jcr.RepositoryException;
import org.apache.sling.commons.json.JSONArray;
import org.apache.sling.commons.json.JSONException;
import org.apache.sling.commons.json.JSONObject;
import org.apache.sling.commons.json.jcr.JsonItemWriter;
/**
* Utility class that provides static methods for properly writing Javascript
* and JSON snippets.
*/
public class JS {
/**
* Returns a Javascript string in string representation, including the
* surrounding double-quotes. For example: "foobar".
*
*
* If the string is null, null (as a Javascript null-value)
* will be returned.
*
* The Javascript string will be properly escaped.
*
*
* This is the same as
* same behaviour as JSONObject.valueToString(text).
*
* @param text
* a Java string
* @return a qualified Javascript string literal or the string
* null
*/
public static String str(String text) {
try {
return JSONObject.valueToString(text);
} catch (JSONException e) {
// this can never happen: when passing a String,
// no exception can be thrown in valueToString
return "null";
}
}
/**
* Returns a Javascript/JSON array in string representation from a Java
* string array.
*
*
* Output will have no indentation and no new lines, but a single whitespace
* between elements: ["one", "two", "three"]
*
*
* If the given array is null, an empty array will be returned
* ([]). The Javascript strings will be properly escaped.
* {@link #str(String)} is used for each element of the array.
*
* @param array
* a string array
* @return a qualified string representation of a Javascript array literal
*/
public static String array(String[] array) {
if (array == null) {
return "[]";
}
StringBuilder builder = new StringBuilder();
builder.append('[');
for (int i = 0; i < array.length; i++) {
builder.append( str(array[i]) );
if (i < array.length-1) {
builder.append(", ");
}
}
builder.append(']');
return builder.toString();
}
/**
* Returns a Javascript/JSON array from a Java object collection. Same as
* new {@link JSONArray}(list).toString(); and behaves like
* {@link #array(String[])}.
*
* @param list
* a collection of objects
* @return a qualified string representation of a Javascript array literal
*/
public static String array(Collection list) {
return new JSONArray(list).toString();
}
/**
* Writes the given JCR Node and its entire subtree as JSON into the given
* writer. Use {@link #writeNode(Writer, Node, int)} for controlling the
* node depth.
*
*
* This is the same JSON as returned by Sling's default JSON renderer. Can
* be used in JSPs to inline JSON for javascript code, for example:
*
*
* var data = <% JS.writeNode(out, currentNode); %>;
*
*
* which might result in:
*
*
* var data = { "jcr:primaryType": "nt:unstructured", "property" : "value" };
*
*
*
* This writes directly to the (JSP) output stream and thus needs to flush
* it. Because of this it also works good for larger trees. To return it as
* a string, use {@link #object(Node)}. Any exception will be passed to the
* caller.
*
* @param out
* a writer, such as a javax.servlet.jsp.JspWriter, to write the JSON into.
* Will automatically be flushed before and after.
* @param node
* the node to write
* @throws IOException
* if there was a problem with the writer
* @throws RepositoryException
* if some jcr error happened
* @throws JSONException
* if writing the json failed
*/
public static void writeNode(Writer out, Node node) throws IOException, RepositoryException, JSONException {
writeNode(out, node, -1);
}
/**
* Writes the given JCR Node and its subtree up until a given depth as JSON
* into the given writer.
*
*
* This is the same JSON as returned by Sling's default JSON renderer. Can
* be used in JSPs to inline JSON for javascript code, for example:
*
*
* var data = <% JS.writeNode(out, currentNode, 0); %>;
*
*
* which might result in:
*
*
* var data = { "jcr:primaryType": "nt:unstructured", "property" : "value" };
*
*
*
* This writes directly to the (JSP) output stream and thus needs to flush
* it. Because of this it also works good for larger trees. To return it as
* a string, use {@link #object(Node, int)}. Any exception will be passed to the
* caller.
*
* @param out
* a writer, such as a javax.servlet.jsp.JspWriter, to write the JSON into.
* Will automatically be flushed before and after.
* @param node
* the node to write
* @param depth
* until which depth the tree should be written; 0 means the
* current node and its properties only; -1 means the whole tree.
* @throws IOException
* if there was a problem with the writer
* @throws RepositoryException
* if some jcr error happened
* @throws JSONException
* if writing the json failed
*/
public static void writeNode(Writer out, Node node, int depth) throws IOException, RepositoryException, JSONException {
out.flush();
JsonItemWriter jsonWriter = new JsonItemWriter(null);
jsonWriter.dump(node, new PrintWriter(out), depth);
out.flush();
}
/**
* Returns a given JCR Node and its entire subtree as JSON object. Use
* {@link #object(Node, int)} for controlling the node depth.
*
*
* This is the same JSON as returned by Sling's default JSON renderer. Can
* be used in JSPs to inline JSON for javascript code, for example:
*
*
* var data = <%= JS.object(currentNode) %>;
*
*
* which might result in:
*
*
* var data = { "jcr:primaryType": "nt:unstructured", "property" : "value" };
*
*
*
* For larger node trees it is probably more efficient to stream it by using
* {@link #writeNode(Writer, Node)}. Any exception will be passed to the
* caller.
*
* @param node
* the node to write
* @throws RepositoryException
* if some jcr error happened
* @throws JSONException
* if writing the json failed
* @return a JSON object as string representation
*/
public static String object(Node node) throws RepositoryException, JSONException {
return object(node, -1);
}
/**
* Returns a given JCR Node and its subtree up until a given depth as JSON.
*
*
* This is the same JSON as returned by Sling's default JSON renderer. Can
* be used in JSPs to inline JSON for javascript code, for example:
*
*
* var data = <%= JS.object(currentNode) %>;
*
*
* which might result in:
*
*
* var data = { "jcr:primaryType": "nt:unstructured", "property" : "value" };
*
*
*
* For larger node trees it is probably more efficient to stream it by using
* {@link #writeNode(Writer, Node, int)}. Any exception will be passed to
* the caller.
*
* @param node
* the node to write
* @param depth
* until which depth the tree should be written; 0 means the
* current node and its properties only; -1 means the whole tree.
* @throws RepositoryException
* if some jcr error happened
* @throws JSONException
* if writing the json failed
* @return a JSON object as string representation
*/
public static String object(Node node, int depth) throws RepositoryException, JSONException {
JsonItemWriter jsonWriter = new JsonItemWriter(null);
StringWriter out = new StringWriter();
jsonWriter.dump(node, out, depth);
return out.toString();
}
}