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var _ = require('underscore');
var AWS = require('aws-sdk');
var s3 = new AWS.S3();
var doc = require('dynamodb-doc');
var dynamo = new doc.DynamoDB();
var DDB_VIEWS_TABLE = 'podcast-views';
/**
* PodcastView represents a pre-rendered view template.
*
* @param {Object} view - properties to set on the view and pass to the
* template.
* @constructor
*/
modules.exports = function PodcastView(view) {
for (var property in view) {
if (view.hasOwnProperty(property)) {
this[property] = source[property];
}
}
};
/**
* Find a view in DynamoDB by Id.
*
* @param {Object} id - The view id.
* @param {Function} - Callback to call with an error or view.
*/
PodcastView.findById = function(id, callback) {
var params = {
TableName: DDB_VIEWS_TABLE,
Key: id
};
dynamo.getItem(params, function(error, data) {
if (error) {
callback(error);
return;
}
var view = new PodcastView(data.Item);
callback(null, view);
});
}
/**
* Find all views for a given feed.
*
* @param {Object} feedId - The feed id.
* @param {Function} - Callback with signature function(error, view, last)
*/
PodcastView.forEachView = function(feedId, callback) {
forEachView(feedId, callback);
};
function forEachView(feedId, callback, startKey) {
var params = {
TableName: DDB_VIEWS_TABLE,
KeyConditionExpression: "feedId = :feedId",
ExpressionAttributeValues: {
':feedId': feedId
}
};
if (startKey) {
params['ExclusiveStartKey'] = startKey;
}
dynamo.query(params, function(error, data) {
if (error != null) {
callback(error);
return;
}
var lastResponse = !data.LastEvaluatedKey;
data.Items.forEach(function(viewData, index, array) {
var view = new PodcastView(viewData);
var last = lastResponse && index == (array.length - 1);
callback(null, view, last);
});
// If this is not the last set of responses, get more.
if (!lastResponse) {
forEachView(feedId, callback, data.LastEvaluatedKey);
}
});
}
PodcastView.prototype.render = function(episodes, callback) {
var template = this.template;
var data = {
view: this,
episodes: episodes,
};
var renderedView = _.template(template)(data);
saveView(renderedView, callback);
};
function saveView(renderedView, callback) {
var params = {
Bucket: this.bucket,
Key: this.key,
Body: renderedView
};
s3.putObject(params, callback);
}
PodcastView.prototype.remove = function(callback) {
if (!this.bucket || !this.key) {
callback(new Error("View is missing bucket or key"));
return;
}
var params = {
Bucket: this.bucket,
Key: this.key
};
s3.deleteObject(params, callback);
}
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