1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 | 2x 16x 16x 22x 6x 16x 2x 6x 6x 6x 16x 16x 16x 16x 16x 32x 6x 6x 6x 6x 10x 10x 16x 10x 10x 4x 8x 8x 8x 8x 4x 2x 2x 16x 2x 24x 24x 24x 32x 32x 32x 24x 16x 10x 10x 10x 16x 8x 8x 8x 8x 24x | import { visit } from 'graphql' import { print } from 'graphql/language/printer' import { ApolloLink, Observable, createOperation } from 'apollo-link' import { BatchLink } from 'apollo-link-batch' const extractGroupInfo = operation => { const variables = {} for (let name in operation.variables) { if (operation.includes.indexOf(name) === -1) { variables[name] = operation.variables[name] } } return { key: `${print(operation.query)}|${JSON.stringify(variables)}`, includes: operation.includes, operationName: operation.operationName, variables: variables, query: operation.query } } const batchHandler = (operations, forward) => { // Early exit in case only one operation is available. Iif (operations.length === 1) { return forward[0](operations[0]).map(result => [result]) } const groups = {} for (let i in operations) { const { key, includes, variables, operationName, query, extensions = {} } = extractGroupInfo(operations[i]) // Ensure group exists. groups[key] = groups[key] || { operations: [], includes: [], variables, operationName, query, extensions } // Attach operation info. groups[key].operations.push(operations[i]) // Merge extensions. groups[key].extensions = { ...groups[key].extensions, ...extensions } // Enforce enabled includes. for (let j in includes) { groups[key].variables[includes[j]] = groups[key].variables[includes[j]] || operations[i].variables[includes[j]] } } // Use first forward as default. // @TODO: this might break context usage from here on! const forwarder = forward[0] return new Observable(observer => { const results = [] for (let key in groups) { const { operationName, query, variables, extensions, operations: groupOperations } = groups[key] const combinedContext = groupOperations.reduce( (combined, operation) => ({ ...combined, ...operation.getContext() }), {} ) const combinedOperation = createOperation(combinedContext, { operationName, query, variables, extensions }) // Dispatch operation // @TODO: handle errors down the link stream. forwarder(combinedOperation).subscribe(result => { groupOperations.forEach(operation => { const context = combinedOperation.getContext() context.httpResponse = context.response // Save response context. operation.setContext(context) // Register as many results as there were // original operations in this group. results.push(result) }) if (results.length === operations.length) { observer.next(results) observer.complete() } }) } }) } /** * Group queries per operationName. */ const batchKey = ({ operationName }) => operationName || null /** * Determines if an operation can be combined based on the existence * of both an operationName and @include directives. */ const defaultCanCombine = operation => { // Early exit when operation is not named. Iif (!operation.operationName) return false let hasIncludes = false visit(operation.query, { Directive: ( { name: { value: name }, arguments: args }, key, parent, path, ancestors ) => { Eif (name === 'include') { hasIncludes = true // Save include variables for further reference. operation.includes = (operation.includes || []).concat( args[0].value.name.value ) } } }) // Early exit when operation has no include directive. if (!hasIncludes) return false return true } export class CombineIncludesLink extends ApolloLink { /** * The batching link. */ batcher /** * A callback to determine if an operation can be combined. */ canCombine constructor ({ /** * The interval at which to batch, in milliseconds. */ batchInterval = 10, /** * The maximum number of operations to include in one fetch. */ batchMax = 10, /** * A custom callback to determine if an operation can be combined. * * Defaults to accounting */ canCombine = defaultCanCombine } = {}) { super() this.canCombine = canCombine this.batcher = new BatchLink({ batchInterval, batchMax, batchHandler, batchKey }) } normalizeResponse = operation => result => { const context = operation.getContext() context.response = context.httpResponse operation.setContext(context) return result } /** * Link query requester. */ request = (operation, forward) => // Can this operation be combined? this.canCombine(operation, defaultCanCombine) ? this.batcher .request(operation, forward) .map(this.normalizeResponse(operation)) : forward(operation) } |