Android Open Source - couchdroid Couch Update

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License

The source code is released under:

Apache License

Java Source Code

/**
 * Copyright (c) 2012 Raymond Wilson (http://www.bytefoundry.co.uk) 
 * /*ww w .  j  av a  2s  .c om*/
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */
package census.couchdroid;

import java.util.ArrayList;
import java.util.List;

import org.apache.http.NameValuePair;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.message.BasicNameValuePair;

/**
 * The 'Update' is a mechanism for executing document update handlers against existing documents. These
 * handlers are server-side functions that exist in your database's design documents that allow you to do things
 * such as providing a server-side last modified timestamp, updating individual fields in a document without 
 * first getting the latest revision, etc. See the following web page for more information:
 * <p/>
 * http://wiki.apache.org/couchdb/Document_Update_Handlers
 * 
 * @author rwilson
 *
 */
public class CouchUpdate {
    protected String name;
    protected String docId;
    protected boolean usePOST;
    protected List<NameValuePair> params;
    
    /**
     * Standard c-tor
     * @param name The name should be in the format "[designDoc]/[update]" e.g "accounts/personal" (corresponding
     *     to "_design/accounts/_update/personal/").
     */
    public CouchUpdate(String name) {
        this.name = name;       
        docId = null;
        usePOST = false;
        params = new ArrayList<NameValuePair>();
    }   
        
    /**
     * Overloaded C-tor with ID of document to update specified.
     * @param name
     * @param docId
     */
    public CouchUpdate(String name, String docId) {
        this.name = name;
        this.docId = docId;
        usePOST = false;
        params = new ArrayList<NameValuePair>();
    }
    
    /**
     * Overloaded c-tor with doc ID and whether or not to use POST method specified. Note the default
     * update method is PUT with the data passed via a query string. 
     * @param name
     * @param docId
     * @param usePOST
     */
    public CouchUpdate(String name, String docId, boolean usePOST) {
        this.name = name;
        this.docId = docId;
        this.usePOST = usePOST;
        params = new ArrayList<NameValuePair>();
    }
    
    /**
     * The ID of the document to update. This is a requirement and the update will fail
     * without it.
     * @param docId
     */
    public void setDocId(String docId) {
        this.docId = docId;
    }
    
    /**
     * Get the ID of the document to update.
     * @return
     */
    public String getDocId() {
        return docId;
    }
    
    /**
     * The name of design document and the update function in the format "[designDoc]/[updateFunc]" e.g. 
     * "accounts/personal" (corresponding to "_design/accounts/_update/personal").
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }
    
    /**
     * Get the name of the update handler.
     * @return
     */
    public String getName() {
        return name;
    }
    
    /**
     * Set whether or not to use POST rather than PUT. Note that your document update handler must be 
     * written to use POST parameters (e.g. 'req.form.field' as opposed to 'req.query.field').
     * @param usePOST
     */
    public void setMethodPOST(boolean usePOST) {
        this.usePOST = usePOST;
    }
    
    /**
     * Get whether or not to use the POST method.
     * @return
     */
    public boolean getMethodPOST() {
        return usePOST;
    }
    
    /**
     * Add a key/value parameter to be passed to the document update handler function. Note that if 
     * the key already exists, all instances of it will be removed prior to insertion.
     * @param key
     * @param value
     */
    public void addParameter(String key, String value) {
        if ((key == null) || (key.equals(""))) {
            return;
        }
        
        removeParameter(key);
        
        params.add(new BasicNameValuePair(key, value));
    }
    
    /**
     * Remove a key/value parameter from being passed to the document update handler function. If 
     * multiple instances of the key exists they will all be removed.
     * @param key
     */
    public void removeParameter(String key) {
        if ((key == null) || (key.equals(""))) {
            return;
        }
        
        List<NameValuePair> toRemove = new ArrayList<NameValuePair>();
        
        for (NameValuePair p : params) {
            if (p.getName().equals(key)) {
                toRemove.add(p);
            }
        }       
        
        for (NameValuePair p : toRemove) {
            params.remove(p);
        }
    }
    
    /**
     * Return the parameters as a query string. You're unlikely to call this yourself as it will be called 
     * by the Database::updateDocment() method depending on whether or not it is using PUT or POST.
     * @return
     */
    public String getQueryString() {
        String qs = "";
        
        for (NameValuePair p : params) {
            qs += p.getName() + "=" + p.getValue() + "&"; 
        }
        
        // Strip the trailing ampersand
        if (qs.endsWith("&")) {
            qs = qs.substring(0, (qs.length() - 1));
        }
        
        return qs;
    }
    
    /**
     * Return the parameters in a format compatible with the 'x-www-form-urlencoded' content type. This 
     * is called by the Database::updateDocument() method to perform a POST update
     * @return
     */
    public String getURLFormEncodedString() {
        return URLEncodedUtils.format(params, "UTF-8");
    }
}

Java Source Code List

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